WO2010113507A1

WO2010113507A1 - Double-stranded molecule inhibiting the expression of gpc3

Info

Publication number: WO2010113507A1
Application number: PCT/JP2010/002379
Authority: WO
Inventors: Yusuke Nakamura; Ryuji Ohsawa; Akiko Konuma
Original assignee: Oncotherapy Science Inc
Current assignee: Oncotherapy Science Inc
Priority date: 2009-04-02
Filing date: 2010-03-31
Publication date: 2010-10-07
Anticipated expiration: 2011-10-02

Abstract

The invention features an isolated double-stranded molecule inhibiting a growth of GPC3 expressing cell. The invention also features a method for treating GPC3-related disease including esophageal cancer, gastric cancer, hepatic cancer, osteosarcoma, soft tissue cancer or endometriosis by administering the double-stranded molecule against a GPC3 gene. Furthermore, the invention features products, including the double-stranded molecules and vectors encoding them, as well as compositions containing the molecules or vectors, useful in the provided methods.

Description

DOUBLE-STRANDED MOLECULE INHIBITING THE EXPRESSION OF GPC3

Cross-Reference to Related Applications
The present application claims the benefit of U.S. Provisional Application No. 61/211,797, filed April 2, 2009, the entire disclosure of which is hereby incorporated herein by reference.

Technical Field
The present invention relates to the field of biological science, more specifically to the field of cancer research. In particular, the present invention relates to a double-stranded nucleic acid molecule that inhibits the expression of GPC3, and a composition containing the same. The present invention further relates to methods of treating cancer using the molecules or compositions.

RNA interference (RNAi) can be induced by transfection of double-stranded molecules, including short interfering RNA (siRNA). In RNAi, one strand of double-stranded molecule has the polynucleotide sequence that is identical or substantially identical to the nucleotide sequence of the targeted gene transcript (i.e., the mRNA), whereas the second strand of the double-stranded molecule has a complementary sequence thereto. Without wishing to be bound by theory, it is generally accepted that once the double-stranded molecules are introduced into a cell or are generated from longer double-stranded molecules in the cell by the RNaseIII-like enzyme, the double-stranded molecule associates with a protein complex, known as the RNA-induced silencing complex (RISC).

The RISC then guides the small double-stranded molecule to the mRNA where the two strands of the double-stranded molecule separate, at which point the antisense strand associates with the mRNA and a nuclease cleaves the mRNA at the antisense strand : double-stranded molecule binding site (NPL 1/Hammond SM et al., Nature 2000 Mar 16, 404(6775): 293-6). The mRNA is subsequently further degraded by cellular nucleases. Short hairpin types have been shown to be potent RNAi triggers and, in some instances, may be more effective than double-stranded molecules (NPL 2/Siolas D et al., Nat Biotechnol 2005 Feb, 23(2): 227-31, Epub 2004 Dec 26). Short hairpin RNAs (shRNAs) may be produced by chemical synthesis as well as recombinant methods.

In recent years, a new approach of cancer therapy using gene-specific siRNA has undergone clinical trial (NPL 3/Bumcrot D et al., Nat Chem Biol 2006 Dec, 2(12): 711-9). Although RNAi seems to have already earned a place among the major technology platforms (NPL 4/Putral LN et al., Drug News Perspect 2006 Jul-Aug, 19(6): 317-24; NPL 5/Frantz S, Nat Rev Drug Discov 2006 Jul, 5(7): 528-9; NPL 6/Dykxhoorn DM et al., Gene Ther 2006 Mar, 13(6): 541-52), problems for clinical use remain. For example, the possibility of toxicity related to the silencing of partially homologous genes or the induction of universal gene suppression by activating the interferon response has been recognized in the art (NPL 7/Judge AD et al., Nat Biotechnol 2005 Apr, 23(4): 457-62, Epub 2005 Mar 20; NPL 8/Jackson AL & Linsley PS, Trends Genet 2004 Nov, 20(11): 521-4).

Glypican 3 (GPC3: Genbank Accession No. NM_004484; SEQ ID NO: 1) encodes a protein (SEQ ID NO: 2) having a molecular weight of 66 kD. GPC3 is a member of the family of cell surface heparan sulfate proteoglycans known to link to the extracytoplasmic cell-surface membrane by means of a glycosylphosphatidylinositol anchor (NPL 9/Filmus J and Selleck SB, J Clin Invest 2001; 108: 497-501). Heparan sulfate proteoglycans are known to interact with growth factors through heparan sulfate chains (NPL 10/Zhang Z et al., J Biol Chem 2001; 276: 41921-9, NPL 11/Paine-Saunders S et al., Dev Biol 2000; 225: 179-87, NPL 12/Grisaru S et al., Dev Biol 2001; 231: 31-46). In addition, GPC3 has been known as an oncofetal protein that overexpressed in some carcinoma, including hepatocellular carcinoma and gastric carcinoma.

GPC3 is also a candidate serum marker for the disease because GPC3 is detectable in the serum of cancer patients (NPL 13/Hippo Y et al., Cancer Res 2004; 64: 2418-23, NPL 14/Capurro M et al., Gastroenterology 2003; 125: 89-97). GPC3 may also find utility as a target for cancer immunotherapy (NPL 15/Nakatsura T et al., Clin Can Res 2004; 10: 8630-40). To that end, an anti-GPC3 monoclonal antibody against C-terminal region of GPC3 has been shown to induce antibody-dependent cellular cytotoxicity (NPL 16/Ishiguro T et al., Cancer Res 2008; 68: 9832-38). Thus, GPC3 may not only be useful for diagnosis of some types of cancer but also as a target of cancer therapy.

[NPL 1] Hammond SM et al., Nature 2000 Mar 16, 404(6775): 293-6
[NPL 2 ]Siolas D et al., Nat Biotechnol 2005 Feb, 23(2): 227-31, Epub 2004 Dec 26
[NPL 3] Bumcrot D et al., Nat Chem Biol 2006 Dec, 2(12): 711-9
[NPL 4] Putral LN et al., Drug News Perspect 2006 Jul-Aug, 19(6): 317-24
[NPL 5] Frantz S, Nat Rev Drug Discov 2006 Jul, 5(7): 528-9
[NPL 6] Dykxhoorn DM et al., Gene Ther 2006 Mar, 13(6): 541-52
[NPL 7] Judge AD et al., Nat Biotechnol 2005 Apr, 23(4): 457-62, Epub 2005 Mar 20
[NPL 8] Jackson AL & Linsley PS, Trends Genet 2004 Nov, 20(11): 521-4
[NPL 9] Filmus J and Selleck SB, J Clin Invest 2001; 108: 497-501
[NPL 10 ]Zhang Z et al., J Biol Chem 2001; 276: 41921-9
[NPL 11] Paine-Saunders S et al., Dev Biol 2000; 225: 179-87
[NPL 12] Grisaru S et al., Dev Biol 2001; 231: 31-46
[NPL 13] Hippo Y et al., Cancer Res 2004; 64: 2418-23
[NPL 14] Capurro M et al., Gastroenterology 2003; 125: 89-97
[NPL 15] Nakatsura T et al., Clin Can Res 2004; 10: 8630-40
[NPL 16] Ishiguro T et al., Cancer Res 2008; 68: 9832-38

The present invention is based, at least in part, on the discovery that double-stranded nucleic acid molecules having specific nucleotide sequences (in particular, SEQ ID NOs: 16 and 28) are effective in inhibiting cellular growth of esophagus cancer cell line. In particular, the present invention provides small interfering RNAs (siRNAs) that target the GPC3 gene.
Accordingly, it is an object of the present invention to provide the double-stranded nucleic acid molecules that target the GPC3 gene or the vectors encoding them that can express the double-stranded nucleic acid molecules both in vivo and in vitro.

The double-stranded nucleic acid molecules and vectors of the present invention have the ability to inhibit cell growth of cells expressing the GPC3 gene. Thus, it is a further object of the present invention to provide methods for inhibiting cell growth and treating GPC3-related disease by administering the double-stranded nucleic acid molecules or vectors of the present invention. Such methods may include administering to a subject a composition containing one or more of the double-stranded nucleic acid molecules or vectors.
It is yet a further object of the present invention to provide compositions for treating GPC3-related disease containing at least one of the double-stranded nucleic acid molecules or vectors of the present invention.

In addition to the above, other objects and features of the invention will become more fully apparent when the following detailed description is read in conjunction with the accompanying examples, data, figures and all reasonable inferences to be drawn therefrom, alone or with consideration of the references incorporated herein. However, it is to be understood that both the foregoing summary of the invention and the following detailed description are of exemplified embodiments, and not restrictive of the invention or other alternate embodiments of the invention. In particular, while the invention is described herein with reference to a number of specific embodiments, it will be appreciated that the description is illustrative of the invention and is not constructed as limiting of the invention. Various modifications and applications may occur to those who are skilled in the art, without departing from the spirit and the scope of the invention, as described by the appended claims.

Various aspects and applications of the present invention will become apparent to the skilled artisan upon consideration of the brief description of the figures and the detailed description of the present invention and its preferred embodiments that follows.

Part (A) depicts the expression analysis of GPC3 in cancer cell lines by RT-PCR. Four breast cancer cell lines and fifteen esophagus cancer cell lines were used in this analysis. Part (B) depicts the results of treatment with GPC3-si#4 and GPC3-si#8 demonstrating the knock down effect. Knock down effects by siRNA treatment were assessed using siRNA transfected TE8 cells by RT-PCR. Treatments with GPC3-si#4 or GPC3-si#8 decreased mRNA expression of GPC3 in the TE8 cells.

Figure 2 depicts the measurement of inhibition of cell proliferation using optimized siRNA sequences against the GPC3 gene. Nine siRNAs against the GPC3 gene (GPC3-si#1~si#9) were synthesized and used in this experiment. Transfection with no oligonucleotide and with an siRNA against Luciferase were performed as negative control. Part (A) depicts the growth suppression effect and non-specific cell death inducing ability of siRNAs evaluated using nine siRNAs and TE8 cells, endogenously expressing the GPC3 gene. Statistics analysis of growth suppression with GPC3-si#4 and GPC3-si#8 treatment was performed. Proliferation of TE8 cells was significantly suppressed by treatments with GPC3-si#4 or GPC3-si#8 compared with control in vitro. "*" and "**" mean p<0.05 and p<0.01, respectively (Student's t-test). Part (B) depicts the specificity of RNAi reactions assessed using TE7 cells, in which the expression of the GPC3 gene is hardly detectable.

Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present invention, the preferred methods, devices, and materials are now described. However, before the present materials and methods are described, it is to be understood that the present invention is not limited to the particular sizes, shapes, dimensions, materials, methodologies, protocols, etc., described herein, as these may vary in accordance with routine experimentation and optimization. It is also to be understood that the terminology used in the description is for the purpose of describing the particular versions or embodiments only, and is not intended to limit the scope of the present invention which will be limited only by the appended claims.
The disclosure of each publication, patent or patent application mentioned in this specification is specifically incorporated by reference herein in its entirety. However, nothing herein is to be construed as an admission that the invention is not entitled to antedate such disclosure by virtue of prior invention.

Definitions:
Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. However, in case of conflict, the present specification, including definitions, will control.
The words "a", "an", and "the" as used herein mean "at least one" unless otherwise specifically indicated.

The term "gene", "polynucleotide", "oligonucleotide" "nucleotide", "nucleic acid", and "nucleic acid molecule" are used interchangeably herein to refer to a polymer of nucleic acid residues and, unless otherwise specifically indicated are referred to by their commonly accepted single-letter codes. The terms apply to nucleic acid (nucleotide) polymers in which one or more nucleic acids are linked by ester bonding. The nucleic acid polymers may be composed of DNA, RNA or a combination thereof and encompass both naturally-occurring and non-naturally occurring nucleic acid polymers.

The terms "polypeptide", "peptide", and "protein" are used interchangeably herein to refer to a polymer of amino acid residues. The terms apply to amino acid polymers in which one or more amino acid residue is a modified residue, or a non-naturally occurring residue, such as an artificial chemical mimetic of a corresponding naturally occurring amino acid, as well as to naturally occurring amino acid polymers.

As used herein, the term "isolated double-stranded molecule" refers to a nucleic acid molecule that inhibits expression of a target gene and includes, for example, short interfering RNA (siRNA; e.g., double-stranded ribonucleic acid (dsRNA) or small hairpin RNA (shRNA)) and short interfering DNA/RNA (siD/R-NA; e.g., double-stranded chimera of DNA and RNA (dsD/R-NA) or small hairpin chimera of DNA and RNA (shD/R-NA)). Herein, the double-stranded molecule is also referred to as "double-stranded nucleic acid molecule".

As used herein, a target sequence is a nucleotide sequence within mRNA or cDNA sequence of a target gene, which will result in suppress of translation of the whole mRNA of the target gene if the double-stranded molecule is introduced within a cell expressing the gene. A nucleotide sequence within mRNA or cDNA sequence of a target gene can be determined to be a target sequence when a double-stranded molecule having a sequence corresponding to the target sequence inhibits expression of the gene in a cell expressing the gene. When a target sequence is shown by cDNA sequence, a sense strand sequence of a double-stranded cDNA, i.e., a sequence that mRNA sequence is converted into DNA sequence, is used for defining a target sequence. A double-stranded molecule is composed of a sense strand that has a sequence corresponding to a target sequence and a antisense strand that has a complementary sequence to the target sequence, and the antisense strand hybridizes with the sense strand at the complementary sequence to form a double-stranded molecule.

Herein, the phrase " corresponding to" means converting a target sequence according to the kind of nucleic acid that constitutes a sense strand of a double-stranded molecule. For example, when a target sequence is shown in DNA sequence and a sense strand of a double-stranded molecule has an RNA region, base "t"s within the RNA region is replaced with base "u"s. On the other hand, when a target sequence is shown in RNA sequence and a sense strand of a double-stranded molecule has a DNA region, base "u"s within the DNA region is replaced with "t"s.

For example, when a target sequence is the DNA sequence shown in SEQ ID NO: 16 or 28 and the sense strand of the double-stranded molecule is composed of RNA, "a sequence corresponding to a target sequence" is "GUUCAGUAAGGACUGUGGC" (for SEQ ID NO: 16) or "CCAGCUCCUGAGAACCAUG" (for SEQ ID NO: 28). Also, a complementary sequence to a target sequence for an antisense strand of a double-stranded molecule can be defined according to the kind of nucleic acid that constitutes the antisense strand. For example, when a target sequence is the DNA sequence shown in SEQ ID NO: 16 or 28 and the antisense strand of the double-stranded molecule is composed of RNA, " a complementary sequence to a target sequence " is "GCCACAGUCCUUACUGAAC" (for SEQ ID NO: 16) or "CAUGGUUCUCAGGAGCUGG" (for SEQ ID NO: 28).

A double-stranded molecule may has one or two 3'overhangs having 2 to 5 nucleotides in length (e.g., uu) and/or a loop sequence that links a sense strand and an antisense strand to form hairpin structure, in addition to a sequence corresponding to a target sequence and complementary sequence thereto.
As used herein, the term "siRNA" refers to a double-stranded RNA molecule which prevents translation of a target mRNA. Standard techniques of introducing siRNA into the cell are used, including those in which DNA is a template from which RNA is transcribed. The siRNA includes sense nucleic acid sequence (also referred to as "sense strand"), complementary antisense nucleic acid sequence (also referred to as "antisense strand") or both. The siRNA may be constructed such that a single transcript has both the sense and complementary antisense nucleic acid sequences of the target gene, e.g., a hairpin. The siRNA may either be a dsRNA or shRNA.

As used herein, the term "dsRNA" refers to a construct of two RNA molecules composed of complementary sequences to one another and that have annealed together via the complementary sequences to form a double-stranded RNA molecule. The nucleotide sequence of two strands may include not only the "sense" or "antisense" RNAs selected from a protein coding sequence of target gene sequence, but also RNA molecule having a nucleotide sequence selected from non-coding region of the target gene.

The term "shRNA", as used herein, refers to an siRNA having a stem-loop structure, composed of first and second regions complementary to one another, i.e., sense and antisense strands. The degree of complementarity and orientation of the regions is sufficient such that base pairing occurs between the regions, the first and second regions may be joined by a loop region, and the loop results from a lack of base pairing between nucleotides (or nucleotide analogs) within the loop region. The loop region of an shRNA is a single-stranded region intervening between the sense and antisense strands and may also be referred to as "intervening single-strand".

As used herein, the term "siD/R-NA" refers to a double-stranded polynucleotide molecule which is composed of both RNA and DNA, and includes hybrids and chimeras of RNA and DNA and prevents translation of a target mRNA. Herein, a hybrid indicates a molecule wherein a polynucleotide composed of DNA and a polynucleotide composed of RNA hybridize to each other to form the double-stranded molecule; whereas a chimera indicates that one or both of the strands composing the double stranded molecule may contain RNA and DNA. Standard techniques of introducing siD/R-NA into the cell are used. The siD/R-NA includes sense strand, antisense strand or both. The siD/R-NA may be constructed such that a single transcript has both the sense and complementary antisense nucleic acid sequences from the target gene, e.g., a hairpin. The siD/R-NA may either be a dsD/R-NA or shD/R-NA.

As used herein, the term "dsD/R-NA" refers to a construct of two molecules composed of complementary sequences to one another and that have annealed together via the complementary sequences to form a double-stranded polynucleotide molecule. The nucleotide sequence of two strands may include not only the "sense" or "antisense" polynucleotides sequence selected from a protein coding sequence of target gene sequence, but also polynucleotide having a nucleotide sequence selected from non-coding region of the target gene. One or both of the two molecules constructing the dsD/R-NA are composed of both RNA and DNA (chimeric molecule), or alternatively, one of the molecules is composed of RNA and the other is composed of DNA (hybrid double-strand).

The term "shD/R-NA", as used herein, refers to an siD/R-NA having a stem-loop structure, composed of a first and second regions complementary to one another, i.e., sense and antisense strands. The degree of complementarity and orientation of the regions is sufficient such that base pairing occurs between the regions, the first and second regions being joined by a loop region, the loop results from a lack of base pairing between nucleotides (or nucleotide analogs) within the loop region. The loop region of an shD/R-NA is a single-stranded region intervening between the sense and antisense strands and may also be referred to as "intervening single-strand".
As used herein, an "isolated nucleic acid" is a nucleic acid removed from its original environment (e.g., the natural environment if naturally occurring) and thus, synthetically altered from its natural state. In the present invention, examples of isolated nucleic acid includes DNA, RNA, and derivatives thereof.

Double-stranded molecules and vectors:
GPC3 (glypican3) belongs to the cell surface heparan sulfate proteoglycan family whose members contain a core protein (about 60 kD) anchored to the cytoplasmic membrane via a glycosyl phosphatidylinositol linkage. A typical sequence of the GPC3 gene is shown in SEQ ID NO: 1 (Genbank Accession No. NM_004484) , and the amino acid sequence of the GPC3 protein encoded by the gene sequence is shown in SEQ ID NO: 2 (Genbank Accession No. NP_004475.1).
A double-stranded molecule against GPC3, i.e., a molecule whose antisense strand hybridizes to the GPC3 mRNA, induces degradation of the mRNA by guiding the RISC to the mRNA, thereby interfering with translation and thus, inhibiting expression of the protein. As demonstrated herein, the expression of GPC3 in an esophageal cancer cell line was inhibited by dsRNAs designed against the GPC3 gene (Fig. 1B). Also, the dsRNAs inhibited the cell proliferation of the cell line when the dsRNAs were introduced into the cell (Fig. 2A).

Therefore the present invention provides isolated double-stranded molecules that are capable of inhibiting the expression of the GPC3 gene as well as cell proliferation when introduced into a cell expressing the GPC3 gene. The target sequences of the double-stranded molecules may be designed by an siRNA design algorithm such as that mentioned below:
SEQ ID NO: 16 (at the position 931-949nt of SEQ ID NO: 1) and
SEQ ID NO: 28 (at the position 1600-1618nt of SEQ ID NO: 1).

Specifically, the present invention provides the following double-stranded molecules of[1] to[16]:
[1] An isolated double-stranded molecule that, when introduced into a cell expressing the GPC gene, inhibits the expression of the GPC3 gene and cell proliferation, such molecules composed of a sense strand and an antisense strand complementary thereto, hybridized to each other to form the double-stranded molecule;
[2] The double-stranded molecule of [1], wherein the sense strand has a sequence corresponding to a target sequence selected from among SEQ ID NOs: 16 and 28;
[3] The double-stranded molecule of [2], having a length of between about 19 and about 100 nucleotides;
[4] The double-stranded molecule of [3], having a length of between about 19 and about 25 nucleotides;
[5] The double-stranded molecule of [1], composed of a single polynucleotide having both the sense and antisense strands linked by an intervening single-strand;
[6] The double-stranded molecule of [5], having the general formula 5'-[A]-[B]-[A']-3', wherein[A] is the sense strand containing a sequence corresponding to a target sequence selected from among SEQ ID NOs: 16 and 28,[B] is the intervening single-strand composed of 3 to 23 nucleotides, and[A'] is the antisense strand containing a sequence complementary to[A];
[7] The double-stranded molecule of any one of [1] to[6], composed of RNA;
[8] The double-stranded molecule of any one of [1] to[6], composed of both DNA and RNA;
[9] The double-stranded molecule of [8], wherein the molecule is a hybrid of a DNA polynucleotide and an RNA polynucleotide;
[10] The double-stranded molecule of [9] wherein the sense and the antisense strands are composed of DNA and RNA, respectively;
[11] The double-stranded molecule of [8], wherein the molecule is a chimera of DNA and RNA;
[12] The double-stranded molecule of [11], wherein a region flanking to the 3'-end of the antisense strand, or both of a region flanking to the 5'-end of the sense strand and a region flanking to the 3'-end of the antisense strand are RNA;
[13] The double-stranded molecule of [16], wherein the flanking region is composed of 9 to 13 nucleotides;
[14] The double-stranded molecule of any one of [1] to[13], wherein the molecule contains one or two 3' overhangs;
[15] The double-stranded molecule of [14], wherein the 3' overhang has a length of between 2 and 5 nucleotides;
[16] A vector expressing the double-stranded molecule of any one of [1] to[15];
[18] A vector containing a sequence that encodes the sense strand of the double-stranded molecule of any one of [1] to[16];
[19] A vector containing a sequence that encodes the antisense strand of the double-stranded molecule of any one of [1] to[18];
[20] A vector set containing the vector of [18] and the vector of [19], wherein the sense strand and the antisense strand are encoded in the each vector separately; and
[21] Vectors containing each of a combination of a polynucleotide having a sense strand nucleic acid and an antisense strand nucleic acid, wherein the sense strand has a sequence corresponding to a target sequence selected from among SEQ ID NOs: 16 and 28, and has a length of between about 19 to about 25 nucleotides and the antisense strand nucleic acid consists of a nucleotide sequence complementary to the sense strand, wherein the transcripts of the sense strand and antisense strand hybridize to each other to form a double-stranded molecule, and wherein the vector, when introduced into a cell expressing the GPC3 gene, inhibits cell proliferation.

I. Double-stranded molecules of the present invention:
The double-stranded molecule of the present invention will be described in more detail below.

Methods for designing double-stranded molecules having the ability to inhibit target gene expression in cells are known. (See, for example, US Patent No. 6,506,559, herein incorporated by reference in its entirety). For example, a computer program for designing siRNAs is available from the Ambion website (www.ambion.com/techlib/misc/siRNA_finder.html).
The computer program selects target nucleotide sequences for double-stranded molecules based on the following protocol.

Selection of Target Sites:
1. Beginning with the AUG start codon of the transcript, scan downstream for AA di-nucleotide sequences. Record the occurrence of each AA and the 3' adjacent 19 nucleotides as potential siRNA target sites. Tuschl et al. recommend to avoid designing siRNA to the 5' and 3' untranslated regions (UTRs) and regions near the start codon (within 75 bases) as these may be richer in regulatory protein binding sites, and UTR-binding proteins and/or translation initiation complexes may interfere with binding of the siRNA endonuclease complex.
2. Compare the potential target sites to the appropriate genome database (human, mouse, rat, etc.) and eliminate from consideration any target sequences with significant homology to other coding sequences. Homology search against other coding sequences may be conducted using the BLAST search engine, which can be found on the NCBI server at: www.ncbi.nlm.nih.gov/BLAST/ (Altschul SF et al., Nucleic Acids Res 1997 Sep 1, 25(17): 3389-402).
3. Select qualifying target sequences for synthesis. Selecting several target sequences along the length of the gene to evaluate is typical.
In the present invention, the target sequences of the double-stranded molecules against the GPC3 gene were designed as:
SEQ ID NOs: 7, 10, 13, 16, 19, 22, 25, 28 and 31.

Double-stranded molecules targeting the above-mentioned target sequences were respectively examined for their ability to suppress the growth of cells expressing the target genes. Among above target sequences, the double-stranded molecules designed for the target sequences shown in SEQ ID NO: 16 or SEQ ID NO: 28, significantly inhibited the cell growth in cells expressing the GPC gene while they had no effect on cells in which the GPC expression was hardly detectable. Therefore, in preferred embodiments, the double-stranded molecules of the present invention target a nucleotide sequence selected from the group consisting of
SEQ ID NO: 16 (at the position 931-949nt of SEQ ID NO: 1) and SEQ ID NO: 28 (at the position 1600-1618nt of SEQ ID NO: 1).

Examples of double-stranded molecules of the present invention that target the above-mentioned target sequence of the GPC3 gene include isolated polynucleotides that contain the nucleic acid sequences corresponding to target sequences and/or complementary sequences to the target sequences. Preferred examples of polynucleotides targeting the GPC3 gene include those containing the sequence corresponding to SEQ ID NO: 16 or 28 and/or complementary sequences to these sequences.

In an embodiment, a double-stranded molecule is composed of two polynucleotides, one polynucleotide has a sequence corresponding to a target sequence, i.e., sense strand, and another polypeptide has a complementary sequence to the target sequence, i.e., antisense strand. The sense strand polynucleotide and the antisense strand polynucleotide hybridize to each other to form double-stranded molecule. Examples of such double-stranded molecules include dsRNA and dsD/R-NA .
In an another embodiment, a double-stranded molecule is composed of a polynucleotide that has both a sequence corresponding to a target sequence, i.e., sense strand, and a complementary sequence to the target sequence, i.e., antisense strand. Generally, the sense strand and the antisense strand are linked by a intervening strand, and hybridize to each other to form a hairpin loop structure. Examples of such double-stranded molecule include shRNA and shD/R-NA.

In other words, a double-stranded molecule of the present invention comprises a sense strand polynucleotide having a nucleotide sequence of the target sequence and anti-sense strand polynucleotide having a nucleotide sequence complementary to the target sequence, and both of polynucleotides hybridize to each other to form the double-stranded molecule. In the double-stranded molecule comprising the polynucleotides, a part of the polynucleotide of either or both of the strands may be RNA, and when the target sequence is defined with a DNA sequence, the nucleotide "t" within the target sequence and complementary sequence thereto is replaced with "u".
In one embodiment of the present invention, such a double-stranded molecule of the present invention comprises a stem-loop structure, composed of the sense and antisense strands. The sense and antisense strands may be joined by a loop. Accordingly, the present invention also provides the double-stranded molecule comprising a single polynucleotide containing both the sense strand and the antisense strand linked or flanked by an intervening single-strand.

In the present invention, double-stranded molecules targeting the GPC3 gene may have a sequence selected from among SEQ ID NOs: 7, 10, 13, 16, 19, 22, 25, 28 and 31 as a target sequence. In preferred embodiments, the target sequence is a sequence of SEQ ID NO: 16 or 28. Accordingly, preferable examples of the double-stranded molecule of the present invention include polynucleotides that hybridize to each other at a sequence corresponding to SEQ ID NO: 16 or 28 and a complementary sequence thereto, and a polynucleotide that has a sequence corresponding to SEQ ID NO: 16 or 28 and a complementary sequence thereto.

However, the present invention is not limited to these examples, and minor modifications in the aforementioned nucleic acid sequences are acceptable so long as the modified molecule retains the ability to suppress the expression of the GPC3 gene. Herein, the phrase "minor modification" as used in connection with a nucleic acid sequence indicates one, two or several substitution, deletion, addition or insertion of nucleotides to the sequence.
In the context of the present invention, the term "several" as applies to nucleotide substitutions, deletions, additions and/or insertions may mean 3-7, preferably 3-5, more preferably 3-4, even more preferably 3 nucleic acid residues. In a preferred embodiment, the number of modified constitute no more than 5% of the total sequence.

According to the present invention, a double-stranded molecule of the present invention can be tested for its ability using the methods described in the Examples below. In the Examples herein below, double-stranded molecules composed of sense strands of various portions of mRNA of the GPC3 gene and antisense strands complementary thereto were tested in vitro for their ability to decrease production of a GPC3 gene product in esophageal cancer cell lines according to standard methods. Furthermore, for example, reduction in a GPC3 gene product production in cells transfeted with candidate double-stranded molecules as compared to that in cells transfected no oligonucleotide or a negative control siRNA ( e.g., siRNA against the luciferase gene) can be detected by, e.g., RT-PCR using primers for the GPC3 mRNA mentioned under Example 1 "Semi-quantitative RT-PCR". Candidate target sequences that decrease the production of a GPC3 gene product in in vitro cell-based assays can then be tested for their inhibitory effects on cell growth. Target sequences that inhibit cell growth in in vitro cell-based assay may be further tested for their in vivo ability using animals with cancer, e.g., nude mouse xenograft models, to confirm decreased production of the GPC3 product and decreased cancer cell growth.

When the isolated polynucleotide is an RNA or derivative thereof, base "t" should be replaced with "u" in the nucleotide sequences. As used herein, the term "complementary" refers to Watson-Crick or Hoogsteen base pairing between nucleotides units of a polynucleotide, and the term "binding" means the physical or chemical interaction between two polynucleotides. When the polynucleotide includes modified nucleotides and/or non-phosphodiester linkages, these polynucleotides may also bind each other as same manner. Generally, complementary polynucleotide sequences to each other hybridize under appropriate conditions to form stable duplexes containing few or no mismatches. Furthermore, the sense strand and antisense strand of the isolated polynucleotide of the present invention can form double-stranded molecule or hairpin loop structure by the hybridization. In a preferred embodiment, such duplexes contain no more than 1 mismatch for every 10 matches. In an especially preferred embodiment, where the strands of the duplex are fully complementary, such duplexes contain no mismatches.

The polynucleotide is preferably less than 2,382 nucleotides in length. For example, the polynucleotide is less than 500, 200, 100, 75, 50, or 25 nucleotides in length for all of the genes. The isolated polynucleotides of the present invention are useful for forming double-stranded molecules against the GPC3 gene or preparing template DNAs encoding the double-stranded molecules. When the polynucleotides are used for forming double-stranded molecules, the sense strand of polynucleotide may be longer than 19 nucleotides, preferably longer than 21 nucleotides, and more preferably has a length of between about 19 and 25 nucleotides. Accordingly, the present invention provides the double-stranded molecules composed of a sense strand and an antisense strand, wherein the sense strand has a nucleotide sequence corresponding to a target sequence. In preferable embodiments, the sense strand hybridizes with antisense strand at the target sequence to form the double-stranded molecule having between 19 and 25 nucleotide pair in length.

The double-stranded molecule serves as a guide for identifying homologous sequences in mRNA for the RISC complex, when the double-stranded molecule is introduced into cells. The identified target RNA is cleaved and degraded by the nuclease activity of Dicer, through which the double-stranded molecule eventually decreases or inhibits production (expression) of the polypeptide encoded by the RNA. Thus, a double-stranded molecule of the invention can be defined by its ability to generate a single-strand that specifically hybridizes to the mRNA of the GPC3 gene under stringent conditions. Herein, the portion of the mRNA that hybridizes with the single-strand generated from the double-stranded molecule is referred to as "target sequence", "target nucleic acid" or "target nucleotide". In the present invention, the nucleotide sequence of the "target sequence" can be shown using not only the RNA sequence of the mRNA, but also the DNA sequence of cDNA synthesized from the mRNA.

The double-stranded molecules of the invention may contain one or more modified nucleotides and/or non-phosphodiester linkages. Chemical modifications well known in the art are capable of increasing stability, availability, and/or cell uptake of the double-stranded molecule. The skilled person will be aware of other types of chemical modification which may be incorporated into the present molecules (WO03/070744; WO2005/045037). In one embodiment, modifications can be used to provide improved resistance to degradation or improved uptake. Examples of such modifications include, but are not limited to, phosphorothioate linkages, 2'-O-methyl ribonucleotides (especially on the sense strand of a double-stranded molecule), 2'-deoxy-fluoro ribonucleotides, 2'-deoxy ribonucleotides, "universal base" nucleotides, 5'-C- methyl nucleotides, and inverted deoxybasic residue incorporation (US20060122137).

In another embodiment, modifications can be used to enhance the stability or to increase targeting efficiency of the double-stranded molecule. Examples of such modifications include, but are not limited to, chemical cross linking between the two complementary strands of a double-stranded molecule, chemical modification of a 3' or 5' terminus of a strand of a double-stranded molecule, sugar modifications, nucleobase modifications and/or backbone modifications, 2-fluoro modified ribonucleotides and 2'-deoxy ribonucleotides (WO2004/029212). In another embodiment, modifications can be used to increased or decreased affinity for the complementary nucleotides in the target mRNA and/or in the complementary double-stranded molecule strand (WO2005/044976). For example, an unmodified pyrimidine nucleotide can be substituted for a 2-thio, 5-alkynyl, 5-methyl, or 5-propynyl pyrimidine. Additionally, an unmodified purine can be substituted with a 7-deaza, 7-alkyl, or 7-alkenyl purine. In another embodiment, when the double-stranded molecule is a double-stranded molecule with a 3' overhang, the 3'- terminal nucleotide overhanging nucleotides may be replaced with deoxyribonucleotides (Elbashir SM et al., Genes Dev 2001 Jan 15, 15(2): 188-200). For further details, published documents such as US20060234970 are available. The present invention is not limited to these examples and any known chemical modifications may be employed for the double-stranded molecules of the present invention so long as the resulting molecule retains the ability to inhibit the expression of the target gene.

Furthermore, the double-stranded molecules of the invention may include both DNA and RNA, e.g., dsD/R-NA or shD/R-NA. Specifically, a hybrid polynucleotide of a DNA strand and an RNA strand or a DNA-RNA chimera polynucleotide shows increased stability. Mixing of DNA and RNA, i.e., a hybrid type double-stranded molecule composed of a DNA strand (polynucleotide) and an RNA strand (polynucleotide), a chimera type double-stranded molecule containing both DNA and RNA on either or both of the single strands (polynucleotides), or the like may be formed for enhancing stability of the double-stranded molecule.
The hybrid of a DNA strand and an RNA strand may be either where the sense strand is DNA and the antisense strand is RNA, or the opposite so long as it can inhibit expression of the target gene when introduced into a cell expressing the gene. Preferably, the sense strand polynucleotide is DNA and the antisense strand polynucleotide is RNA. Also, the chimera type double-stranded molecule may be either where both of the sense and antisense strands are composed of DNA and RNA, or where any one of the sense and antisense strands are composed of DNA and RNA so long as it has an activity to inhibit expression of the target gene when introduced into a cell expressing the gene. In order to enhance stability of the double-stranded molecule, the molecule preferably contains as much DNA as possible, whereas to induce inhibition of the target gene expression, the molecule is required to be RNA within a range to induce sufficient inhibition of the expression.

As a preferred example of the chimera type double-stranded molecule, an upstream partial region (i.e., a region flanking to the target sequence or complementary sequence thereof within the sense or antisense strands) of the double-stranded molecule is RNA. Preferably, the upstream partial region indicates the 5' side (5'-end) of the sense strand and the 3' side (3'-end) of the antisense strand. Alternatively, regions flanking to 5'-end of sense strand and/or 3'-end of antisense strand are referred to upstream partial region. That is, in preferred embodiments, a region flanking to the 3'-end of the antisense strand, or both of a region flanking to the 5'-end of the sense strand and a region flanking to the 3'-end of the antisense strand are composed of RNA. For instance, the chimera or hybrid type double-stranded molecule of the present invention include following combinations:
sense strand:
5'-[---DNA---]-3'
3'-(RNA)-[DNA]-5'
:antisense strand,
sense strand:
5'-(RNA)-[DNA]-3'
3'-(RNA)-[DNA]-5'
:antisense strand, and
sense strand:
5'-(RNA)-[DNA]-3'
3'-(---RNA---)-5'
:antisense strand.

The upstream partial region preferably is a domain composed of 9 to 13 nucleotides counted from the terminus of the target sequence or complementary sequence thereto within the sense or antisense strands of the double-stranded molecules. Moreover, preferred examples of such chimera type double-stranded molecules include those having a strand length of 19 to 21 nucleotides in which at least the upstream half region (5' side region for the sense strand and 3' side region for the antisense strand) of the double-stranded molecule is RNA and the other half is DNA. In such a chimera type double-stranded molecule, the effect to inhibit expression of the target gene is much higher when the entire antisense strand is RNA (US20050004064).

In the present invention, the double-stranded molecule may form a hairpin, such as a short hairpin RNA (shRNA) and short hairpin consisting of DNA and RNA (shD/R-NA). The shRNA or shD/R-NA is a sequence of RNA or mixture of RNA and DNA making a tight hairpin turn that can be used to silence gene expression via RNA interference. The shRNA or shD/R-NA includes a sense strand containing a sequence corresponding to the target sequence and a antisense strand containing a complementary sequence to the target sequence on a single strand wherein the sequences are separated by a loop sequence. Generally, the hairpin structure is cleaved by the cellular machinery into dsRNA or dsD/R-NA, which is then bound to the RNA-induced silencing complex (RISC). This complex binds to and cleaves mRNAs which match the target sequence of the dsRNA or dsD/R-NA.

A loop sequence composed of an arbitrary nucleotide sequence can be located between the sense and antisense sequence in order to form the hairpin loop structure. Thus, the present invention also provides a double-stranded molecule having the general formula 5'-[A]-[B]-[A']-3', wherein[A] is the sense strand containing a sequence corresponding to a target sequence,[B] is an intervening single-strand and[A'] is the antisense strand containing a complementary sequence to[A]. The target sequence may be selected from among, for example, sequences of SEQ ID NOs: 7, 10, 13, 16, 19, 22, 25, 28 and 31. Preferably, the target sequence may be selected from among sequences of SEQ ID NOs: 16 and 28.

The present invention is not limited to these examples, and the target sequence in[A] may be modified sequences from these examples so long as the double-stranded molecule retains the ability to suppress the expression of the targeted GPC3 gene. The region[A] hybridizes to[A'] to form a loop composed of the region[B]. The intervening single-stranded portion[B], i.e., loop sequence may be preferably 3 to 23 nucleotides in length. The loop sequence, for example, can be selected from among the following sequences (www.ambion.com/techlib/tb/tb_506.html). Furthermore, a loop sequence consisting of 23 nucleotides also provides active siRNA (Jacque JM et al., Nature 2002 Jul 25, 418(6896): 435-8, Epub 2002 Jun 26):
CCC, CCACC, or CCACACC: Jacque JM et al., Nature 2002 Jul 25, 418(6896): 435-8, Epub 2002 Jun 26;
UUCG: Lee NS et al., Nat Biotechnol 2002 May, 20(5): 500-5; Fruscoloni P et al., Proc Natl Acad Sci USA 2003 Feb 18, 100(4): 1639-44, Epub 2003 Feb 10; and
UUCAAGAGA: Dykxhoorn DM et al., Nat Rev Mol Cell Biol 2003 Jun, 4(6): 457-67.

Examples of preferred double-stranded molecules of the present invention having hairpin loop structure are shown below. In the following structure, the loop sequence can be selected from among AUG, CCC, UUCG, CCACC, CTCGAG, AAGCUU, CCACACC, and UUCAAGAGA; however, the present invention is not limited thereto:
GUUCAGUAAGGACUGUGGC-[B]-GCCACAGUCCUUACUGAAC (for target sequence SEQ ID NO: 16), and
CCAGCUCCUGAGAACCAUG-[B]-CAUGGUUCUCAGGAGCUGG (for target sequence SEQ ID NO: 28).

Furthermore, in order to enhance the inhibition activity of the double-stranded molecules, several nucleotides can be added to 3'end of the sense strand and/or antisense strand of the double-stranded molecule, as 3' overhangs. The number of nucleotides to be added is at least 2, generally 2 to 10, preferably 2 to 5. The added nucleotides form single strand at the 3'end of the sense strand and/or antisense strand of the double-stranded molecule. The nucleotides for 3' overhang are preferably "u" or "t", but are not limited to. When the double-stranded molecule has a hairpin loop structure, a 3' overhang is added to the 3' end of the antisense strand.

The method for preparing the double-stranded molecule is not particularly limited, though it is preferable to use a chemical synthetic method known in the art. According to the chemical synthesis method, sense and antisense single-stranded polynucleotides are separately synthesized and then annealed together via an appropriate method to obtain a double-stranded molecule. Specific example for the annealing includes wherein the synthesized single-stranded polynucleotides are mixed in a molar ratio of preferably at least about 3:7, more preferably about 4:6, and most preferably substantially equimolar amount (i.e., a molar ratio of about 5:5). Next, the mixture is heated to a temperature at which double-stranded molecules dissociate and then is gradually cooled down. The annealed double-stranded polynucleotide can be purified by usually employed methods known in the art. Examples of purification methods include methods utilizing agarose gel electrophoresis. Remaining single-stranded polynucleotides may be optionally removed by, e.g., degradation with appropriate enzyme.

Alternatively, the double-stranded molecules may be transcribed intracellularly by cloning its coding sequence into a vector containing a regulatory sequence that directs the expression of the double-stranded molecule in an adequate cell (e.g., a RNA poly III transcription unit from the small nuclear RNA (snRNA) U6 or the human H1 RNA promoter) adjacent to the coding sequence. The regulatory sequences flanking the coding sequences of double-stranded molecule may be identical or different, such that their expression can be modulated independently, or in a temporal or spatial manner. Details of vectors which are capable of producing the double-stranded molecules will be described bellow.

II. Vectors containing a double-stranded molecule of the present invention:
Also included in the present invention are vectors containing one or more of the double-stranded molecules described herein, and a cell containing such a vector. A vector of the present invention preferably encodes a double-stranded molecule of the present invention in an expressible form. Herein, the phrase "in an expressible form" indicates that the vector, when introduced into a cell, will express the molecule. In a preferred embodiment, the vector includes regulatory elements necessary for expression of the double-stranded molecule. Such vectors of the present invention may be used for producing the present double-stranded molecules, or directly as an active ingredient for treating cancer.

Vectors of the present invention can be produced, for example, by cloning GPC3 sequence (i.e., sequence encoding a sense strand and an antisense strand of the doubles-stranded molecule) into an expression vector so that regulatory sequences are operatively-linked to GPC3 sequence in a manner to allow expression (by transcription of the DNA molecule) of both strands (Lee NS et al., Nat Biotechnol 2002 May, 20(5): 500-5). For example, RNA molecule that is the antisense strand is transcribed by a first promoter (e.g., a promoter sequence flanking to the 3' end of the cloned DNA) and RNA molecule that is the sense strand is transcribed by a second promoter (e.g., a promoter sequence flanking to the 5' end of the cloned DNA). After transcribed, the sense and antisense strands hybridize to each other to generate a double-stranded molecule constructs for silencing of the gene. Alternatively, the sense strand and the antisense strand of the double-stranded molecule may be encoded by two vectors respectively. The vectors respectively express the sense and anti-sense strands and then the transcribed strands hybridize to each other to form a double-stranded molecule construct. Furthermore, the cloned sequence may encode a construct having a secondary structure (e.g., hairpin); namely, a single transcript of a vector contains both the sense strand and antisense strand sequences of the double-stranded molecule.

The vectors of the present invention may also be prepared to achieve stable insertion into the genome of the target cell (see, e.g., Thomas KR & Capecchi MR, Cell 1987, 51: 503-12 for a description of homologous recombination cassette vectors). See, e.g., Wolff et al., Science 1990, 247: 1465-8; US Patent Nos. 5,580,859; 5,589,466; 5,804,566; 5,739,118; 5,736,524; 5,679,647; and WO 98/04720. Examples of DNA-based delivery technologies include "naked DNA", facilitated (bupivacaine, polymers, peptide-mediated) delivery, cationic lipid complexes, and particle-mediated ("gene gun") and pressure-mediated delivery (see, e.g., US Patent No. 5,922,687).

The vectors of the present invention include, for example, viral or bacterial vectors. Examples of expression vectors include attenuated viral hosts, such as vaccinia or fowlpox (see, e.g., US Patent No. 4,722,848). This approach involves the use of vaccinia virus, e.g., as a vector to express nucleotide sequences that encode the double-stranded molecule. When introduced into a cell expressing the target gene, the recombinant vaccinia virus expresses the double-stranded molecule and thereby suppresses the proliferation of the cell. Another example of useable vector includes Bacille Calmette Guerin (BCG). BCG vectors are described in Stover et al., Nature 1991, 351: 456-60. A wide variety of other vectors are useful for therapeutic administration and production of the double-stranded molecules; examples include adeno and adeno-associated virus vectors, retroviral vectors, Salmonella typhi vectors, detoxified anthrax toxin vectors, and the like. See, e.g., Shata et al., Mol Med Today 2000, 6: 66-71; Shedlock et al., J Leukoc Biol 2000, 68: 793-806; and Hipp et al., In Vivo 2000, 14: 571-85.

Alternatively, the present invention provides vectors including each of a combination of polynucleotide having a sense strand nucleic acid and an antisense strand nucleic acid, wherein the sense strand has a sequence corresponding to a target sequence selected from among SEQ ID NOs: 7, 10, 13, 16, 19, 22, 25, 28 and 31, and the antisense strand nucleic acid consists of a sequence complementary to the sense strand, wherein the transcripts of the sense strand and the antisense strand hybridize to each other to form a double-stranded molecule, and wherein the vectors, when introduced into a cell expressing the GPC3, inhibits expression of the gene. Preferably, the polynucleotide is an oligonucleotide of between about 19 and 25 nucleotides pair in length (e.g., contiguous nucleotides from the nucleotide sequence of SEQ ID NO: 1. More preferably, the combination of polynucleotide includes a single nucleotide transcript having the sense strand and the antisense strand linked via a single-stranded nucleotide sequence. More preferably, the combination of polynucleotide has the general formula 5'-[A]-[B]-[A']-3', wherein[A] is a nucleotide sequence corresponding to a target sequence selected from among SEQ ID NOs: 7, 10, 13, 16, 19, 22, 25, 28 and 31;[B] is a nucleotide sequence consisting of about 3 to about 23 nucleotide; and[A'] is a nucleotide sequence complementary to[A].

Methods of inhibiting or reducing growth of a cancer cell and treating cancer using a double-stranded molecule of the present invention:
In the present invention, some dsRNAs against the GPC3 gene were tested for their ability to inhibit cell growth. The two of them, which significantly suppressed the growth of cells expressing the GPC3 gene, were also tested for their knock down effect, and effectively knocked down the expression of the gene in esophageal cancer cell lines.
Therefore, the present invention provides methods for inhibiting cell growth, e.g., growth of esophageal cancer cell, gastric cancer cell, hepatic cancer cell, osteosarcoma cell, soft tissue cancer cell or endometriosis related cell, by inducing dysfunction of the GPC3 gene via inhibiting the expression of GPC3. GPC3 gene expression can be inhibited by any of the aforementioned double-stranded molecules of the present invention which specifically target of the GPC3 gene or the vectors of the present invention that can express any of the double-stranded molecules.

Such ability of the present double-stranded molecules and vectors to inhibit GPC3 expressing cell growth indicates that they can be used for methods for treating GPC3 -related disease. Thus, the present invention provides methods to treat patients with GPC3 -related disease, e.g., esophageal cancer, gastric cancer, hepatic cancer, osteosarcoma, soft tissue cancer or endometriosis, by administering a double-stranded molecule against the GPC3 gene or a vector expressing the molecule. The treatment methods of the present invention are expected to cause little adverse effect because the GPC3 gene was hardly detected in normal organs.

Specifically, the present invention provides the following methods of[1] to[18]:
[1] A method for inhibiting a growth of GPC3 expressing cell and treating GPC3 -related disease, which method includes the step of administering at least one isolated double-stranded molecule inhibiting the expression of GPC3 in the cell and the cell proliferation, wherein the molecule is composed of a sense strand and an antisense strand complementary thereto, hybridized to each other to form the double-stranded molecule.
[2] The method of [1], wherein the sense strand has a sequence corresponding to a target sequence selected from among SEQ ID NOs: 16 and 28;
[3] The method of [1] or [2], wherein the GPC3 -related disease to be treated is esophageal cancer, gastric cancer, hepatic cancer, osteosarcoma, soft tissue cancer or endometriosis;
[4] The method of any one of [1] to[3], wherein plural kinds of the double-stranded molecules are administered;
[5] The method of any one of [1] to[4], wherein the double-stranded molecule has a length of between about 19 and about 100 nucleotides;
[6] The method of [5], wherein the double-stranded molecule has a length of between about 19 and about 25 nucleotides;
[7] The method of any one of [1] to [6], wherein the double-stranded molecule is composed of a single polynucleotide containing both the sense strand and the antisense strand linked by an intervening single-strand;
[8] The method of [7], wherein the double-stranded molecule has the general formula 5'-[A]-[B]-[A']-3', wherein[A] is the sense strand containing a sequence corresponding to a target sequence selected from among SEQ ID NOs: 16 and 28,[B] is the intervening single strand composed of 3 to 23 nucleotides, and[A'] is the antisense strand containing a sequence complementary to[A];
[9] The method of any one of [1] to[8], wherein the double-stranded molecule is an RNA;
[10] The method of any one of [1] to[8], wherein the double-stranded molecule contains both DNA and RNA;
[11] The method of [10], wherein the double-stranded molecule is a hybrid of a DNA polynucleotide and an RNA polynucleotide;
[12] The method of [11], wherein the sense and antisense strand polynucleotides are composed of DNA and RNA, respectively;
[13] The method of [10], wherein the double-stranded molecule is a chimera of DNA and RNA;
[14] The method of [13], wherein a region flanking to the 3'-end of the antisense strand, or both of a region flanking to the 5'-end of the sense strand and a region flanking to the 3'-end of the antisense strand are composed of RNA;
[15] The method of [14], wherein the flanking region is composed of 9 to 13 nucleotides;
[16] The method of any one of [1] to[15], wherein the double-stranded molecule contains one or two 3' overhangs;
[17] The method of any one of [1] to[16], wherein the double-stranded molecule is encoded by a vector;
[18] The method of any one of [1] to[17], wherein the double-stranded molecule is contained in a composition which includes, in addition to the molecule, a transfection-enhancing agent and pharmaceutically acceptable carrier.
[19] A method for inhibiting a growth of GPC3 expressing cell and treating GPC3 -related disease, which method includes the step of administering at least one vector that encoding at least one isolated double-stranded molecule inhibiting the expression of GPC3 in the cell and the cell proliferation, wherein the molecule is composed of a sense strand and an antisense strand complementary thereto, hybridized to each other to form the double-stranded molecule.
[20] The method of [19], wherein the sense strand has a sequence corresponding to a target sequence selected from among SEQ ID NOs: 16 and 28;
[21] The method of [19] or [20], wherein the GPC3 -related disease to be treated is esophageal cancer, gastric cancer, hepatic cancer, osteosarcoma, soft tissue cancer or endometriosis;
[22] The method of any one of [19] to [21], wherein the vector encodes plural kinds of the double-stranded molecules;
[23] The method of any one of [19] to [22], wherein plural kinds of the vectors are administered;
[24] The method of any one of [19] to [23], wherein the double-stranded molecule has a length of between about 19 and about 100 nucleotides;
[25] The method of [24], wherein the double-stranded molecule has a length of between about 19 and about 25 nucleotides;
[26] The method of any one of [19] to [25], wherein the double-stranded molecule is composed of a single polynucleotide containing both the sense strand and the antisense strand linked by an intervening single-strand;
[27] The method of [26], wherein the double-stranded molecule has the general formula 5'-[A]-[B]-[A']-3', wherein[A] is the sense strand containing a sequence corresponding to a target sequence selected from among SEQ ID NOs: 16 and 28,[B] is the intervening single strand composed of 3 to 23 nucleotides, and[A'] is the antisense strand containing a sequence complementary to [A];
[28] The method of any one of [19] to[27], wherein the double-stranded molecule contains one or two 3' overhangs; and
[29] The method of any one of [19] to[28], wherein the vector is contained in a composition which includes, in addition to the vector, a transfection-enhancing agent and pharmaceutically acceptable carrier.

The method of the present invention will be described in more detail below.
The growth of cells expressing the GPC3 gene may be inhibited by contacting the cells with a double-stranded molecule against the GPC3 gene, a vector expressing the molecule or a composition containing the same. The cells may be further contacted with a transfection agent. Suitable transfection agents are known in the art. The phrase "inhibition of cell growth" indicates that the cell proliferates at a lower rate or has decreased viability as compared to a cell not exposed to the molecule. Cell growth may be measured by methods known in the art, e.g., using the MTT cell proliferation assay.
The growth of any kind of cells may be suppressed according to the present method so long as the cell expresses or over-expresses the GPC3 gene. Exemplary cells include esophageal cancer cell, gastric cancer cell, hepatic cancer cell, osteosarcoma cell, soft tissue cancer cell or endometriosis related cell.

Thus, patients suffering from or at risk of developing disease related to GPC3 may be treated by administering at least one of the present double-stranded molecules, at least one vector expressing at least one of the molecules or at least one composition containing at least one of the molecules. For example, patients of esophageal cancer, gastric cancer, hepatic cancer, osteosarcoma, soft tissue cancer or endometriosis may be treated according to the present methods. The type of disease may be identified by standard methods. In preferred embodiments, patients treated by the methods of the present invention may be selected by detecting the expression of GPC3 in a biopsy specimen from the patient, for example by RT-PCR or immunoassay. Preferably, before the treatment of the present invention, the biopsy specimen from the subject is confirmed for GPC3 gene over-expression by methods known in the art, for example, immunoassay such as immunohistochemical analysis and ELISA, or RT-PCR.

The term "specifically inhibit" as used in the context of inhibitory polynucleotides and polypeptides refers to the ability of an agent or ligand to inhibit the expression or the biological function of GPC3. Specific inhibition typically results in at least about a 2-fold inhibition over background, preferably greater than about 10 fold and most preferably greater than 100-fold inhibition of GPC3 expression (e.g., transcription or translation) or measured biological function (e.g., cell growth or proliferation). Expression levels and/or biological function can be measured in the context of comparing treated and untreated cells, or a cell population before and after treatment. In some embodiments, the expression or biological function of GPC3 is completely inhibited. Typically, specific inhibition is a statistically meaningful reduction in GPC3 expression or biological function (e.g., p < or = 0.05) using an appropriate statistical test.

In some embodiments, plural kinds of the double-stranded molecules against the GPC3 gene (or vectors) may be administered to a subject. According to the present method to inhibit cell growth and thereby treating GPC3 -related disease, when administering plural kinds of the double-stranded molecules (or vectors expressing or compositions containing the same), each of the molecules may have different structures but may act at mRNA which matches the same target sequence of GPC3. Alternatively plural kinds of the double-stranded molecules may acts at mRNA which matches different target sequence of the same gene.
For inhibiting cell growth, a double-stranded molecule of the present invention may be directly introduced into the cells in a form to achieve binding of the molecule with corresponding mRNA transcripts. Alternatively, as described above, a DNA encoding the double-stranded molecule may be introduced into cells as a vector. For introducing the double-stranded molecules or vectors into the cells, transfection-enhancing agent, such as FuGENE (Roche diagnostics), Lipofectamine 2000 (Invitrogen), Oligofectamine (Invitrogen), and Nucleofector (Wako pure Chemical), may be employed.

A treatment is deemed "efficacious" if it leads to clinical benefit such as, reduction in expression of the GPC3 gene, or a decrease in size, prevalence, or metastatic potential of the cancer in the subject. When the treatment is applied prophylactically, "efficacious" means that it retards or prevents GPC3 -related disease from forming, or prevents or alleviates a clinical symptom of disease. Efficaciousness is determined in association with any known method for diagnosing or treating the particular disease type.
It is understood that the double-stranded molecules of the invention degrade the GPC3 mRNA in substoichiometric amounts. Without wishing to be bound by any theory, it is believed that the double-stranded molecules of the invention cause degradation of the target mRNA in a catalytic manner. Thus, compared to standard cancer therapies, significantly less a double-stranded molecule needs to be delivered at or near the site of cancer to exert therapeutic effect.

One skilled in the art can readily determine an effective amount of the double-stranded molecules of the invention to be administered to a given subject, by taking into account factors such as body weight, age, sex, type of disease, symptoms and other conditions of the subject; the route of administration; and whether the administration is regional or systemic. Generally, an effective amount of the double-stranded molecules of the invention is an intercellular concentration of from about 1 nanomolar (nM) to about 100 nM, preferably from about 2 nM to about 50 nM, more preferably from about 2.5 nM to about 10 nM. It is contemplated that greater or smaller amounts of the double-stranded molecules can be administered. The precise dosage required for a particular circumstance may be readily and routinely determined by one of skill in the art.

The present methods can be used to inhibit the growth or metastasis of GPC3-related disease; for example, esophageal cancer, gastric cancer, hepatic cancer, osteosarcoma, soft tissue cancer or endometriosis. In particular, a double-stranded molecule containing a target sequence of GPC3 (i.e., SEQ ID NO: 16 or 28) is particularly preferred for the treatment of esophageal cancer, gastric cancer, hepatic cancer, osteosarcoma, soft tissue cancer or endometriosis.

For treating cancer, the double-stranded molecule of the invention can also be administered to a subject in combination with a pharmaceutical agent different from the double-stranded molecule. Alternatively, the double-stranded molecule of the invention can be administered to a subject in combination with another therapeutic method designed to treat disease. For example, the double-stranded molecule of the invention can be administered in combination with therapeutic methods currently employed for treating cancer or preventing cancer metastasis (e.g., radiation therapy, surgery and treatment using chemotherapeutic agents, such as cisplatin, carboplatin, cyclophosphamide, 5-fluorouracil, adriamycin, daunorubicin or tamoxifen).

In the present methods, the double-stranded molecule can be administered to a subject either as a naked double-stranded molecule, in conjunction with a delivery reagent, or as a recombinant plasmid or viral vector which expresses the double-stranded molecule.
Suitable delivery reagents for administration in conjunction with the present double-stranded molecule include LipoTrust^TM; Mirus Transit TKO lipophilic reagent; lipofectin; lipofectamine; cellfectin; or polycations (e.g., polylysine), or liposomes. A preferred delivery reagent is a liposome.

Liposomes can aid in the delivery of the double-stranded molecule to a particular tissue, such as tumor tissue, and can also increase the blood half-life of the double-stranded molecule. Liposomes suitable for use in the invention are formed from standard vesicle-forming lipids, which generally include neutral or negatively charged phospholipids and a sterol, such as cholesterol. The selection of lipids is generally guided by consideration of factors such as the desired liposome size and half-life of the liposomes in the blood stream. A variety of methods are known for preparing liposomes, for example, as described in Szoka et al., Ann Rev Biophys Bioeng 1980, 9: 467; and US Pat. Nos. 4,235,871; 4,501,728; 4,837,028; and 5,019,369, the entire disclosures of which are herein incorporated by reference.

Preferably, the liposomes encapsulating the present double-stranded molecule includes a ligand molecule that can deliver the liposome to the seat of disease. Ligands which bind to receptors prevalent in tumor or vascular endothelial cells, such as monoclonal antibodies that bind to tumor antigens or endothelial cell surface antigens, are preferred.
Particularly preferably, the liposomes encapsulating the present double-stranded molecule may be modified so as to avoid clearance by the mononuclear macrophage and reticuloendothelial systems, for example, by having opsonization-inhibition moieties bound to the surface of the structure. In one embodiment, a liposome of the invention can include both opsonization-inhibition moieties and a ligand.

Opsonization-inhibiting moieties for use in preparing the liposomes of the invention are typically large hydrophilic polymers that are bound to the liposome membrane. As used herein, an opsonization-inhibiting moiety is "bound" to a liposome membrane when it is chemically or physically attached to the membrane, e.g., by the intercalation of a lipid-soluble anchor into the membrane itself, or by binding directly to active groups of membrane lipids. These opsonization-inhibiting hydrophilic polymers form a protective surface layer which significantly decreases the uptake of the liposomes by the macrophage-monocyte system ("MMS") and reticuloendothelial system ("RES"); e.g., as described in US Pat. No. 4,920,016, the entire disclosure of which is herein incorporated by reference. Liposomes modified with opsonization-inhibition moieties thus remain in the circulation much longer than unmodified liposomes. For this reason, such liposomes are sometimes called "stealth" liposomes.

Stealth liposomes are known to accumulate in tissues fed by porous or "leaky" microvasculature. Thus, target tissue characterized by such microvasculature defects, for example, solid tumors, will efficiently accumulate these liposomes; see Gabizon et al., Proc Natl Acad Sci USA 1988, 18: 6949-53. In addition, the reduced uptake by the RES lowers the toxicity of stealth liposomes by preventing significant accumulation in liver and spleen. Thus, liposomes that are modified with opsonization-inhibition moieties can effectively deliver the present double-stranded molecule to target cells.

Opsonization-inhibiting moieties suitable for modifying liposomes are preferably water-soluble polymers with a molecular weight from about 500 to about 40,000 daltons, and more preferably from about 2,000 to about 20,000 daltons. Such polymers include polyethylene glycol (PEG) or polypropylene glycol (PPG) derivatives; e.g., methoxy PEG or PPG, and PEG or PPG stearate; synthetic polymers such as polyacrylamide or poly N-vinyl pyrrolidone; linear, branched, or dendrimeric polyamidoamines; polyacrylic acids; polyalcohols, e.g., polyvinylalcohol and polyxylitol to which carboxylic or amino groups are chemically linked, as well as gangliosides, such as ganglioside GM1. Copolymers of PEG, methoxy PEG, or methoxy PPG, or derivatives thereof, are also suitable. In addition, the opsonization-inhibiting polymer can be a block copolymer of PEG and either a polyamino acid, polysaccharide, polyamidoamine, polyethyleneamine, or polynucleotide. The opsonization-inhibiting polymers can also be natural polysaccharides containing amino acids or carboxylic acids, e.g., galacturonic acid, glucuronic acid, mannuronic acid, hyaluronic acid, pectic acid, neuraminic acid, alginic acid, carrageenan; aminated polysaccharides or oligosaccharides (linear or branched); or carboxylated polysaccharides or oligosaccharides, e.g., reacted with derivatives of carbonic acids with resultant linking of carboxylic groups.
Preferably, the opsonization-inhibiting moiety is a PEG, PPG, or derivatives thereof. Liposomes modified with PEG or PEG-derivatives are sometimes called "PEGylated liposomes".

The opsonization-inhibiting moiety can be bound to the liposome membrane by any one of numerous well-known techniques. For example, an N-hydroxysuccinimide ester of PEG can be bound to a phosphatidyl-ethanolamine lipid-soluble anchor, and then bound to a membrane. Similarly, a dextran polymer can be derivatized with a stearylamine lipid-soluble anchor via reductive amination using Na(CN)BH₃ and a solvent mixture such as tetrahydrofuran and water in a 30:12 ratio at 60 degrees C.

Vectors expressing a double-stranded molecule of the invention are discussed above. Such vectors expressing at least one double-stranded molecule of the invention can also be administered directly or in conjunction with a suitable delivery reagent, including LipoTrust^TM; Mirus Transit LT1 lipophilic reagent; lipofectin; lipofectamine; cellfectin; polycations (e.g., polylysine) or liposomes. Methods for delivering recombinant viral vectors, which express a double-stranded molecule of the invention, to an area of disease in a patient are within the skill of the art.
The double-stranded molecule of the invention can be administered to a subject by any means suitable for delivering the double-stranded molecule into seat of disease. For example, the double-stranded molecule can be administered by gene gun, electroporation, or by other suitable parenteral or enteral administration routes.

Suitable enteral administration routes include oral, rectal, or intranasal delivery.
Suitable parenteral administration routes include intravascular administration (e.g., intravenous bolus injection, intravenous infusion, intra-arterial bolus injection, intra-arterial infusion and catheter instillation into the vasculature); peri- and intra-tissue injection (e.g., peri-tumoral and intra-tumoral injection); subcutaneous injection or deposition including subcutaneous infusion (such as by osmotic pumps); direct application to the area at or near the seat of disease, for example by a catheter or other placement device (e.g., a suppository or an implant composed of a porous, non-porous, or gelatinous material); and inhalation. It is preferred that injections or infusions of the double-stranded molecule or vector be given at or near the seat of disease.
The double-stranded molecule of the invention can be administered in a single dose or in multiple doses. Where the administration of the double-stranded molecule of the invention is by infusion, the infusion can be a single sustained dose or can be delivered by multiple infusions. Injection of the agent directly into the tissue is at or near the seat of disease preferred. Multiple injections of the agent into the tissue at or near the seat of disease are particularly preferred.

One skilled in the art can also readily determine an appropriate dosage regimen for administering the double-stranded molecule of the invention to a given subject. For example, the double-stranded molecule can be administered to the subject once, for example, as a single injection or deposition at or near the seat of disease. Alternatively, the double-stranded molecule can be administered once or twice daily to a subject for a period of from about three to about twenty-eight days, more preferably from about seven to about ten days. In a preferred dosage regimen, the double-stranded molecule is injected at or near the seat of disease once a day for seven days. Where a dosage regimen includes multiple administrations, it is understood that the effective amount of a double-stranded molecule administered to the subject can include the total amount of a double-stranded molecule administered over the entire dosage regimen.

Pharmaceutical compositions containing double-stranded molecules or vectors of the present invention:
In addition to the above, the present invention also provides pharmaceutical compositions that include at least one of the present double-stranded molecules or the vectors coding for the molecules. Specifically, the present invention provides the following compositions of [1] to[18]:
[1] A composition for inhibiting a growth of GPC3 expressing cell and/or treating GPC3 -related disease, which composition contains at least one isolated double-stranded molecule inhibiting the expression of GPC3 and the cell proliferation, wherein the molecule is composed of a sense strand and an antisense strand complementary thereto, hybridized to each other to form the double-stranded molecule;
[2] The composition of [1], wherein the sense strand has a sequence corresponding to a target sequence selected from among SEQ ID NOs: 16 and 28;
[3] The composition of [1] or[2], wherein the GPC3 -related disease is esophageal cancer, gastric cancer, hepatic cancer, osteosarcoma, soft tissue cancer or endometriosis;
[4] The composition of any one of [1] to [3], wherein the composition contains plural kinds of the double-stranded molecules;
[5] The composition of any one of [1] to[4], wherein the double-stranded molecule has a length of between about 19 and about 100 nucleotides;
[6] The composition of [5], wherein the double-stranded molecule has a length of between about 19 and about 25 nucleotides;
[7] The composition of any one of [1] to[6], wherein the double-stranded molecule is composed of a single polynucleotide containing both the sense strand and the antisense strand linked by an intervening single-strand;
[8] The composition of [7], wherein the double-stranded molecule has the general formula 5'-[A]-[B]-[A']-3', wherein [A] is the sense strand containing a sequence corresponding to a target sequence selected from among SEQ ID NOs: 16 and 28, [B] is the intervening single strand composed of 3 to 23 nucleotides, and[A'] is the antisense strand containing a sequence complementary to [A];
[9] The composition of any one of [1] to [8], wherein the double-stranded molecule is an RNA;
[10] The composition of any one of [1] to [8], wherein the double-stranded molecule contains both DNA and RNA;
[11] The composition of [10], wherein the double-stranded molecule is a hybrid of a DNA polynucleotide and an RNA polynucleotide;
[12] The composition of [11], wherein the sense and antisense strand polynucleotides are composed of DNA and RNA, respectively;
[13] The composition of [10], wherein the double-stranded molecule is a chimera of DNA and RNA;
[14] The composition of [13], wherein a region flanking to the 3'-end of the antisense strand, or both of a region flanking to the 5'-end of the sense strand and a region flanking to the 3'-end of the antisense strand are composed of RNA;
[15] The composition of [14], wherein the flanking region is composed of 9 to 13 nucleotides;
[16] The composition of any one of [1] to [15], wherein the double-stranded molecule contains one or two 3' overhangs;
[17] The composition of any one of [1] to [16], wherein the double-stranded molecule is encoded by a vector;
[18] The composition of any one of [1] to [17], which includes, in addition to the molecule, a transfection-enhancing agent and pharmaceutically acceptable carrier.
[19] A composition for inhibiting a growth of GPC3 expressing cell and/or treating GPC3 -related disease, which composition contains at least one vector that encoding at least one double-stranded molecule inhibiting the expression of GPC3 and the cell proliferation, wherein the molecule is composed of a sense strand and an antisense strand complementary thereto, hybridized to each other to form the double-stranded molecule;
[20] The composition of[19], wherein the sense strand has a sequence corresponding to a target sequence selected from among SEQ ID NOs: 16 and 28;
[21] The composition of[19] or[20], wherein the GPC3 -related disease is esophageal cancer, gastric cancer, hepatic cancer, osteosarcoma, soft tissue cancer or endometriosis;
[22] The composition of any one of[19] to[21], wherein the double-stranded molecule has a length of between about 19 and about 100 nucleotides;
[23] The composition of[22], wherein the double-stranded molecule has a length of between about 19 and about 25 nucleotides;
[24] The composition of any one of[19] to[23], wherein the double-stranded molecule is composed of a single polynucleotide containing both the sense strand and the antisense strand linked by an intervening single-strand;
[25] The composition of[24], wherein the double-stranded molecule has the general formula 5'-[A]-[B]-[A']-3', wherein[A] is the sense strand containing a sequence corresponding to a target sequence selected from among SEQ ID NOs: 16 and 28,[B] is the intervening single strand composed of 3 to 23 nucleotides, and[A'] is the antisense strand containing a sequence complementary to[A];
[26] The composition of any one of[19] to[25], wherein the double-stranded molecule contains one or two 3' overhangs; and
[27] The composition of any one of[19] to[26], wherein the vector encodes plural kinds of the double stranded molecules;
[28] The composition of an one of[19] to[27], wherein the composition contains plural kinds of the vectors; and
[29] The composition of any one of[19] to[28], which includes, in addition to the vector, a transfection-enhancing agent and pharmaceutically acceptable carrier.

Suitable compositions of the present invention are described in additional detail below.
The double-stranded molecules of the invention are preferably formulated as pharmaceutical compositions prior to administering to a subject, according to techniques known in the art. Pharmaceutical compositions of the present invention are characterized as being at least sterile and pyrogen-free. As used herein, "pharmaceutical formulations" include formulations for human and veterinary use. Methods for preparing pharmaceutical compositions of the invention are within the skill in the art, for example as described in Remington's Pharmaceutical Science, 17th ed., Mack Publishing Company, Easton, Pa. (1985), the entire disclosure of which is herein incorporated by reference.

The present pharmaceutical formulations contain at least one of the double-stranded molecules or vectors encoding them of the present invention (e.g., 0.1 to 90% by weight), or a physiologically or pharmaceutically acceptable salt of the molecule, mixed with a physiologically or pharmaceutically acceptable carrier medium. Preferred physiologically or pharmaceutically acceptable carrier media are water, buffered water, normal saline, 0.4% saline, 0.3% glycine, hyaluronic acid and the like.

According to the present invention, the composition may contain plural kinds of the double-stranded molecules, each of the molecules may be directed to the same target sequence, or different target sequences of GPC3.
Furthermore, the present composition may contain a vector coding for one or plural double-stranded molecules. For example, the vector may encode one or two kinds of the present double-stranded molecules. Alternatively, the present composition may contain plural kinds of vectors, each of the vectors coding for a different double-stranded molecule.
Moreover, the present double-stranded molecules may be contained as liposomes in the present composition. Details of liposomes are described above.

Pharmaceutical compositions of the invention can also include conventional pharmaceutical excipients and/or additives. Suitable pharmaceutical excipients include stabilizers, antioxidants, osmolality adjusting agents, buffers, and pH adjusting agents. Suitable additives include physiologically biocompatible buffers (e.g., tromethamine hydrochloride), additions of chelants (such as, for example, DTPA or DTPA-bisamide) or calcium chelate complexes (for example calcium DTPA, CaNaDTPA-bisamide), or, optionally, additions of calcium or sodium salts (for example, calcium chloride, calcium ascorbate, calcium gluconate or calcium lactate). Pharmaceutical compositions of the invention can be packaged for use in liquid form, or can be lyophilized.

For solid compositions, conventional nontoxic solid carriers can be used; for example, pharmaceutical grades of mannitol, lactose, starch, magnesium stearate, sodium saccharin, talcum, cellulose, glucose, sucrose, magnesium carbonate, and the like.

For example, a solid pharmaceutical composition for oral administration can include any of the carriers and excipients listed above and 10-95%, preferably 25-75%, of one or more double-stranded molecule of the invention. A pharmaceutical composition for aerosol (inhalational) administration can include 0.01-20% by weight, preferably 1-10% by weight, of one or more double-stranded molecule of the invention encapsulated in a liposome as described above, and propellant. A carrier can also be included as desired; e.g., lecithin for intranasal delivery.
In addition to the above, the present composition may contain other pharmaceutical active ingredients so long as they do not inhibit the in vivo function of the present double-stranded molecules. For example, the composition may contain chemotherapeutic agents conventionally used for treating cancers.

In another embodiment, the present invention also provides the use of the double-stranded nucleic acid molecules of the present invention in manufacturing a pharmaceutical composition for treating disease characterized by the expression of GPC3. For example, the present invention relates to a use of double-stranded nucleic acid molecule inhibiting the expression of the GPC3 gene in a cell, which molecule includes a sense strand and an antisense strand complementary thereto, hybridized to each other to form the double-stranded nucleic acid molecule and targets to a sequence selected from among SEQ ID NOs: 16 and 28, for manufacturing a pharmaceutical composition for treating GPC3 -related disease, e.g., esophageal cancer, gastric cancer, hepatic cancer, osteosarcoma, soft tissue cancer or endometriosis.

Alternatively, the present invention further provides a method or process for manufacturing a pharmaceutical composition for treating disease characterized by the expression of GPC3, wherein the method or process includes a step for formulating a pharmaceutically or physiologically acceptable carrier with a double-stranded nucleic acid molecule inhibiting the expression of GPC3 in a cell, which over-expresses the gene, which molecule includes a sense strand and an antisense strand complementary thereto, hybridized to each other to form the double-stranded nucleic acid molecule and targets to a sequence selected from among SEQ ID NOs: 16 and 28 as active ingredients.

In another embodiment, the present invention also provides a method or process for manufacturing a pharmaceutical composition for treating disease characterized by the expression of GPC3, wherein the method or process includes a step for admixing an active ingredient with a pharmaceutically or physiologically acceptable carrier, wherein the active ingredient is a double-stranded nucleic acid molecule inhibiting the expression of GPC3 in a cell, which molecule includes a sense strand and an antisense strand complementary thereto, hybridized to each other to form the double-stranded nucleic acid molecule and targets to a sequence selected from among SEQ ID NOs: 16 and 28.

In another embodiment, the present invention also provides the use of the double-stranded nucleic acid molecules of the present invention in manufacturing a pharmaceutical composition for treating a cancer expressing the GPC3 gene. For example, the present invention relates to a use of double-stranded nucleic acid molecule inhibiting the expression of a GPC3 gene in a cell, which over-expresses the gene, wherein the molecule includes a sense strand and an antisense strand complementary thereto, hybridized to each other to form the double-stranded nucleic acid molecule and targets to a sequence selected from the group consisting of SEQ ID NOs: 16 and 28, for manufacturing a pharmaceutical composition for treating a cancer expressing the GPC3 gene.

In the present invention, a cancer overexpressing GPC3 can be treated with at least one active ingredient selected from the group consisting of:
(a) a double-stranded molecule of the present invention,
(b) DNA encoding thereof, and
(c) a vector encoding thereof.

Examples of cancers overexpressing GPC3 include, but are not limited to, esophageal cancer, gastric cancer, hepatic cancer, osteosarcoma, soft tissue cancer or endometriosis. Accordingly, prior to the administration of the pharmaceutical composition containing the active ingredient, it is preferable to confirm whether the expression level of GPC3 in the cancer cells or tissues to be treated is enhanced compared with normal cells of the same organ. Thus, in one embodiment, the present invention provides a method for treating a cancer (over)expressing GPC3, which method may include the steps of:
i) determining the expression level of GPC3 in cancer cells or tissue(s) obtained from a subject with the cancer to be treated;
ii) comparing the expression level of GPC3 with normal control; and
iii) administrating at least one component selected from the group consisting of
(a) a double-stranded molecule of the present invention,
(b) DNA encoding thereof, and
(c) a vector encoding thereof,
to a subject with a cancer overexpressing GPC3 compared with normal control.

Alternatively, the present invention also provides a pharmaceutical composition containing at least one component selected from the group consisting of:
(a) a double-stranded molecule of the present invention,
(b) DNA encoding thereof, and
(c) a vector encoding thereof,
for use in administrating to a subject having a cancer overexpressing GPC3. In other words, the present invention further provides a method for identifying a subject to be treated with:
(a) a double-stranded molecule of the present invention,
(b) DNA encoding thereof, or
(c) a vector encoding thereof,
which method may include the step of determining an expression level of GPC3 in subject-derived cancer cells or tissue(s), wherein an increase of the level compared to a normal control level of the gene indicates that the subject has cancer which may be treated with:
(a) a double-stranded molecule of the present invention,
(b) DNA encoding thereof, or
(c) a vector encoding thereof.

The method of treating a cancer of the present invention will be described in more detail below.
A subject to be treated by the present method is preferably a mammal. Exemplary mammals include, but are not limited to, e.g., human, non-human primate, mouse, rat, dog, cat, horse, and cow.

According to the present invention, the expression level of GPC3 in cancer cells or tissues obtained from a subject is determined. The expression level can be determined at the transcription (nucleic acid) product level, using methods known in the art. For example, the mRNA of GPC3 may be quantified using probes by hybridization methods (e.g., Northern hybridization). The detection may be carried out on a chip or an array. Those skilled in the art can prepare such probes utilizing the sequence information of GPC3 (e.g., SEQ ID NO: 1). For example, the cDNA of GPC3 may be used as the probes. If necessary, the probes may be labeled with a suitable label, such as dyes, fluorescent substances and isotopes, and the expression level of the gene may be detected as the intensity of the hybridized labels.
Furthermore, the transcription product of GPC3 may be quantified using primers by amplification-based detection methods (e.g., RT-PCR). Such primers may be prepared based on the available sequence information of the gene (e.g., SEQ ID NO: 1).

Specifically, a probe or primer used for the present method hybridizes under stringent, moderately stringent, or low stringent conditions to the mRNA of GPC3. As used herein, the phrase "stringent (hybridization) conditions" refers to conditions under which a probe or primer will hybridize to its target sequence, but not to other sequences. Stringent conditions are sequence-dependent and will be different under different circumstances. Specific hybridization of longer sequences is observed at higher temperatures than shorter sequences. Generally, the temperature of a stringent condition is selected to be about 5 degree Centigrade lower than the thermal melting point (Tm) for a specific sequence at a defined ionic strength and pH. The Tm is the temperature (under a defined ionic strength, pH and nucleic acid concentration) at which 50% of the probes complementary to their target sequence hybridize to the target sequence at equilibrium. Since the target sequences are generally present at excess, at Tm, 50% of the probes are occupied at equilibrium. Typically, stringent conditions will be those in which the salt concentration is less than about 1.0 M sodium ion, typically about 0.01 to 1.0 M sodium ion (or other salts) at pH 7.0 to 8.3 and the temperature is at least about 30 degree Centigrade for short probes or primers (e.g., 10 to 50 nucleotides) and at least about 60 degree Centigrade for longer probes or primers. Stringent conditions may also be achieved with the addition of destabilizing agents, such as formamide.

Alternatively, the translation product may be detected for the determination of the expression level of GPC3. For example, the quantity of GPC3 protein (e.g., SEQ ID NO: 2) may be determined. Methods for determining the quantity of the protein as the translation product include immunoassay methods that use an antibody specifically recognizing the protein. The antibody may be monoclonal or polyclonal. Furthermore, any fragment or modification (e.g., chimeric antibody, scFv, Fab, F(ab')₂, Fv, etc.) of the antibody may be used for the detection, so long as the fragment or modified antibody retains the binding ability to the GPC3 protein. Methods to prepare these kinds of antibodies for the detection of proteins are well known in the art, and any method may be employed in the present invention to prepare such antibodies and equivalents thereof.

As another method to detect the expression level of the GPC3 gene based on its translation product, the intensity of staining may be measured via immunohistochemical analysis using an antibody against the GPC3 protein. Namely, in this measurement, strong staining indicates increased presence/level of the protein and, at the same time, high expression level of the GPC3 gene.
The expression level of a target gene, i,e., the GPC3 gene, in cancer cells or tissue(s) obtained from a subject can be determined to be increased if the level increases from the control level (e.g., the level in normal cells) of the target gene by, for example, 10%, 25%, or 50%; or increases to more than 1.1 fold, more than 1.5 fold, more than 2.0 fold, more than 5.0 fold, more than 10.0 fold, or more.

The control level may be determined at the same time with the cancer cells by using a sample(s) previously collected and stored from a subject/subjects whose disease state(s) (cancerous or non-cancerous) is/are known. In addition, normal cells obtained from non-cancerous regions of an organ that has the cancer to be treated may be used as normal control. Alternatively, the control level may be determined by a statistical method based on the results obtained by analyzing previously determined expression level(s) of the GPC3 gene in samples from subjects whose disease states are known. Furthermore, the control level can be derived from a database of expression patterns from previously tested cells. Moreover, according to an aspect of the present invention, the expression level of the GPC3 gene in a cancer cells or tissue sample obtained from a subject may be compared to multiple control levels, which are determined from multiple reference samples. It is preferred to use a control level determined from a reference sample derived from a tissue type similar to that of the subject-derived biological sample. Moreover, it is preferred to use the standard value of the expression levels of the GPC3 gene in a population with a known disease state. The standard value may be obtained by any method known in the art. For example, a range of mean +/- 2 S.D. or mean +/- 3 S.D. may be used as the standard value.

In the context of the present invention, a control level determined from a biological sample that is known to be non-cancerous is referred to as a "normal control level". On the other hand, if the control level is determined from a cancerous biological sample known to over-express GPC3, it is referred to as a "cancerous control level".

When the expression level of the GPC3 gene in cancer cells or tissue(s) obtained from a subject is increased as compared to the normal control level, or is similar/equivalent to the cancerous control level, the subject may be diagnosed with cancer to be treated.
In the present invention, in addition to cancer cells or tissue(s), blood samples such as serum samples may be used for determining the expression level of GPC3 because GPC3 is a serum marker for cancer (WO2004/018667). When the expression level is determined in a blood sample, a standard value determined from multiple reference samples is preferably used as a normal control level.

Methods of diagnosis and kits of the present invention:
More specifically, the present invention provides a method of (i) diagnosing whether a subject has the cancer to be treated, and/or (ii) selecting a subject for cancer treatment, which method includes the steps of:
a) determining the expression level of GPC3 in cancer cells or tissue(s) obtained from a subject who is suspected to have the cancer to be treated;
b) comparing the expression level of GPC3 with a normal control level;
c) diagnosing the subject as having the cancer to be treated, if the expression level of GPC3 is increased as compared to the normal control level; and
d) selecting the subject for cancer treatment, if the subject is diagnosed as having the cancer to be treated, in step c).

Alternatively, such a method may include the steps of:
a) determining the expression level of GPC3 in cancer cells or tissue(s) obtained from a subject who is suspected to have the cancer to be treated;
b) comparing the expression level of GPC3 with a cancerous control level;
c) diagnosing the subject as having the cancer to be treated, if the expression level of GPC3 is similar or equivalent to the cancerous control level; and
d) selecting the subject for cancer treatment, if the subject is diagnosed as having the cancer to be treated, in step c).

The present invention also provides a kit for determining a subject suffering from cancer that can be treated with the double-stranded molecule of the present invention or vector encoding thereof, which may also be useful in assessing and/or monitoring the efficacy of a cancer treatment. Preferably, the cancer includes, but is not limited to, esophageal cancer, gastric cancer, hepatic cancer, osteosarcoma, soft tissue cancer or endometriosis. More particularly, the kit may preferably include at least one reagent for detecting the expression of the GPC3 gene in a subject-derived cancer cells or tissue sample, which reagent may be selected from the group of:
(a) a reagent for detecting mRNA of the GPC3 gene;
(b) a reagent for detecting the GPC3 protein; and
(c) a reagent for detecting the biological activity of the GPC3 protein.
Suitable reagents for detecting mRNA of the GPC3 gene include nucleic acids that specifically bind to or identify the GPC3 mRNA, such as oligonucleotides which have a complementary sequence to a portion of the GPC3 mRNA. These kinds of oligonucleotides are exemplified by primers and probes that are specific to the GPC3 mRNA. These kinds of oligonucleotides may be prepared based on methods well known in the art. If needed, the reagent for detecting the GPC3 mRNA may be immobilized on a solid matrix. Moreover, more than one reagent for detecting the GPC3 mRNA may be included in the kit.

On the other hand, suitable reagents for detecting the GPC3 protein include antibodies to the GPC3 protein. The antibody may be monoclonal or polyclonal. Furthermore, any fragment or modification (e.g., chimeric antibody, scFv, Fab, F(ab')₂, Fv, etc.) of the antibody may be used as the reagent, so long as the fragment or modified antibody retains the binding ability to the GPC3 protein. Methods to prepare these kinds of antibodies for the detection of proteins are well known in the art, and any method may be employed in the present invention to prepare such antibodies and equivalents thereof. Furthermore, the antibody may be labeled with signal generating molecules via direct linkage or an indirect labeling technique. Labels and methods for labeling antibodies and detecting the binding of the antibodies to their targets are well known in the art, and any labels and methods may be employed for the present invention. Moreover, more than one reagent for detecting the GPC3 protein may be included in the kit.

The kit may contain more than one of the aforementioned reagents. For example, tissue samples obtained from subjects without cancer or suffering from cancer, may serve as useful control reagents. A kit of the present invention may further include other materials desirable from a commercial and user standpoint, including buffers, diluents, filters, needles, syringes, and package inserts (e.g., written, tape, CD-ROM, etc.) with instructions for use. These reagents and such may be retained in a container with a label. Suitable containers include bottles, vials, and test tubes. The containers may be formed from a variety of materials, such as glass or plastic.

In an embodiment of the present invention, when the reagent is a probe against the GPC3 mRNA, the reagent may be immobilized on a solid matrix, such as a porous strip, to form at least one detection site. The measurement or detection region of the porous strip may include a plurality of sites, each containing a nucleic acid (probe). A test strip may also contain sites for negative and/or positive controls. Alternatively, control sites may be located on a strip separated from the test strip. Optionally, the different detection sites may contain different amounts of immobilized nucleic acids, i.e., a higher amount in the first detection site and lesser amounts in subsequent sites. Upon the addition of a test sample, the number of sites displaying a detectable signal provides a quantitative indication of the amount of GPC3 mRNA present in the sample. The detection sites may be configured in any suitably detectable shape and are typically in the shape of a bar or dot spanning the width of a test strip.

The kit of the present invention may further include a positive control sample or GPC3 standard sample. The positive control sample of the present invention may be prepared by collecting GPC3 positive samples and then assaying their GPC3 levels. Alternatively, a purified GPC3 protein or polynucleotide may be added to cells that do not express GPC3 or buffers to form the positive sample or the GPC3 standard sample. In the present invention, purified GPC3 may be a recombinant protein. The GPC3 level of the positive control sample is, for example, more than the cut off value.
The following examples are presented to illustrate the present invention and to assist one of ordinary skill in making and using the same. The examples are not intended in any way to otherwise limit the scope of the invention.

While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the invention. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. In case of conflict, the present specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting.

[Example 1] General Methods
Tissue preparation
Clinical tissue samples of gastric cancer, hepatic carcinoma, osteosarcoma, soft tissue cancer and endometriosis were obtained from 40 patients (gastric cancer), 20 patients (hepatic carcinoma), 27 patients (osteosarcoma), 65 patients (soft tissue cancer) and 23 patients (endometriosis) who underwent surgical resection after preoperative informed consent.

cDNA microarrays
Fabrication of the cDNA microarray slides has been described elsewhere (Zembutsu H et al., Cancer Res 2002 Jan 15, 62(2): 518-2.; Nishidate T et al., Int J Oncol 2004 Oct, 25(4): 797-819). For analysis of various cancer expression profiles, the present inventors prepared duplicate sets of slides containing 23,040 (colon cancer, soft tissue sarcoma, and testicular seminoma, prostate cancer) or 27,648 (breast cancer and bladder cancer) or 36,864 (pancreas cancer, NSCLC, SCLC, and esophagus cancer) cDNA spots, to reduce experimental fluctuation. Briefly, for cancer expression analysis, total RNAs were extracted from patients with tumors and from corresponding normal tissues. T7-based RNA amplification was carried out to obtain adequate quantities of RNA for microarray experiments. Aliquots of amplified RNA were labeled by reverse transcription with adequate amounts of Cy5-dCTP or Cy3-dCTP (Amersham Biosciences, Buckinghamshire, United Kingdom). Hybridization, washing, and detection were carried out as described previously (Zembutsu H et al., Cancer Res 2002 Jan 15, 62(2): 518-27; Nishidate T et al., Int J Oncol 2004 Oct, 25(4): 797-819).

Cell line and cell culture
Breast cancer lines, BT-549, MCF-7 and T47D were purchased from Dainippon Sumitomo Pharmaceutical and ZR-75-1 was purchased from ATCC. Esophagus cancer lines, TE1 -15 were obtained from the Cancer Cell Repository, Institute of Development, Aging and Cancer, Tohoku University. These breast cancer and esophagus cancer cell lines were maintained in appropriate culture media for in vitro assay.

Semi-quantitative RT-PCR
Expression level of the GPC3 gene was evaluated in breast cancer and esophagus cancer cell lines using semi-quantitative RT-PCR experiments. Specifically, a 3-microgram aliquot of mRNA from each cell lines transfected with siRNA was reverse-transcribed for single-stranded cDNAs using oligo d(T)16 primer (Roche) and Superscript II (Invitrogen). Expression of beta-actin (ACTB) served as an internal control. The number of cycles in PCR reaction was optimized to ensure product intensity within the linear phase of amplification. Each cDNA mixture was diluted for subsequent PCR amplification with primer sets as follows:
GPC3:
forward primer: 5'- GCTTGGTCTCTTTTCAACAATCC -3' (SEQ ID NO: 3);
reverse primer: 5'- GCAAAAGGACAATCTATATGCTACC -3' (SEQ ID NO: 4);
ACTB:
forward primer: 5'-AGGATGCAGAAGGAGATCAC-3' (SEQ ID NO: 5);
reverse primer: 5'-AGAAAGGGTGTAACGCAACT-3' (SEQ ID NO: 6);

RNAi experiments
Nine siRNAs against the GPC3 gene were synthesized in BEX Co Ltd. 10 pmol/well dsRNA oligo against the GPC3 gene were transfected into TE8 cells (expressing the GPC3 gene) and TE7 cells (not detectable the expression of GPC3) on 96-well microtiter plate (Becton Dickinson) using Lipofectamine2000^TM (Invitrogen). The siRNA against Luciferase (siLuc: target sequence; CTTACGCTGAGTACTTCGA) was used as a negative control. SiTox (Dharmacon) was used as positive control. After transfection of each siRNA to cancer cells, the cell proliferation was examined. The knock down ability of siRNA was determined by RT-PCR.

Cell proliferation assay
The concentration of living cells visualized with calcein was evaluated using IN Cell Analyzer 1000 (GE Healthcare Bio-Science KK) after 96h from transfection of siRNA.

[Example 2] Expression analysis of GPC3 in cancer cells by cDNA microarray and RT-PCR
cDNA microarray analyses were carried out as described previously (Zembutsu H et al., Cancer Res 2002 Jan 15, 62(2): 518-27; Nishidate T et al., Int J Oncol 2004 Oct, 25(4): 797-819). Expression of GPC3 in cancer tissues was compared with that of corresponding normal epithelia, and up-regulation of GPC3 was confirmed in the tissue of gastric cancer, hepatic cancer, osteosarcoma, soft tissue cancer and endometriosis (Table 1). GPC3 is applicable as a therapeutic target for several types of cancer because it is over-expressed (T/N ratio>=3) in clinical samples; 13 of 15 gastric cancer, 15 of 18 hepatic carcinoma, 5 of 9 osteosarcoma, 19 of 21 soft tissue cancers and 6 of 7 endometriosis. Furthermore, semi-quantitative RT-PCR analysis was performed to investigate the expression levels in breast cancer and esophagus cancer cell lines (Figure 1A). GPC3 highly expressed in breast cancer cell line (ZR-75-1) and esophagus cancer cell lines (TE5, TE6, TE8, TE9, TE10, TE11 and TE14).

[Example 3] Design of customized siRNA for candidates
Candidate siRNA sequences against the GPC3 gene were designed using siRNA design tool available on Ambion, Inc. website (www.ambion.com/techlib/misc/siRNA_finder.html) (Tuschl T et al., Genes Dev 1999 Dec 15, 13(24): 3191-7). Furthermore, the screened sequences were carefully selected following algorithm;
(1) G/C content was the range of 30%-60%.
(2) Sequence having polymorphism was excluded.
(3) Nucleic acid following AA was G or C.
(4) Sequence with significant homology to other gene was excluded.
Thus, 9 siRNAs against GPC3 were selected and synthesized to evaluate gene silencing ability and selectivity (Table 2).

[Example 4] Optimization of gene-specific siRNAs and evaluation of their silencing specificity
The GPC3 gene was over-expressed in esophagus cancer cells including clinical sample (Table 1 and Figure 1A). To evaluate effect of siRNA against GPC3, growth suppression assay was performed in GPC3-expressing esophagus cancer cell line (TE8) transfected with each siRNA. Treatment with GPC3-si#4 and GPC3-si#8 significantly suppressed the cell proliferation of TE8 as comparing with control (Figure 2A). On the contrary, no effect was observed in TE7 cells transfected with GPC3-si#4 and GPC3-si#8 (Figure 2B). Thus, undesired non-specific cell death by transfection of GPC3-si#4 and GPC3-si#8 was not appeared.

[Example 5] Knock down effect with transfection of siRNA against GPC3
To assess the knock down effect of transfection with GPC3-si#4 and GPC-si#8, RT-PCR was performed using mRNA obtained from TE8 transfected with each siRNA. Expression level of GPC3 was reduced in TE8 cells by transfection with siRNA for GPC3 (Figure 1B). As a result, growth suppression was consistent with the reduction of GPC3 expression levels in TE8 cells transfected siRNA. Therefore, GPC3 should be applicable to cancer therapy for a wide variety of cancers including gastric cancer, hepatic cancer, osteosarcoma, soft tissue cancer, esophagus cancer and endometriosis.

The present invention demonstrates that the cell growth can be suppressed by double-stranded nucleic acid molecules that specifically target the GPC3 gene. Thus, the novel double-stranded nucleic acid molecules may find use as candidates for the development of anti-GPC3-related disease pharmaceuticals. For example, agents that block the expression of GPC3 protein or prevent its activity may find therapeutic utility as anti-GPC3 -related disease agents, particularly anti-GPC3-related disease agents for the treatment of esophageal cancer, gastric cancer, hepatic cancer, osteosarcoma, soft tissue cancer or endometriosis.

Claims

An isolated double-stranded molecule composed of a sense strand and an antisense strand complementary thereto, hybridized to each other to form the double-stranded molecule, wherein the sense strand comprises a sequence corresponding to a target sequence selected from among SEQ ID NOs: 7, 10, 13, 16, 19, 22, 25, 28 and 31, and has a length of between about 19 and about 25 nucleotides.
The double-stranded molecule of claim 1, wherein the sense strand comprises a sequence corresponding to a target sequence selected from among SEQ ID NOs: 16 and 28.
The double-stranded molecule of claim 1, which consists of a single polynucleotide comprising both a sense strand and an antisense strand linked by an intervening single-strand.
The double-stranded molecule of claim 3, which has the general formula 5'-[A]-[B]-[A']-3', wherein [A] is the sense strand comprising a sequence corresponding to a target sequence selected from the group consisting of SEQ ID NOs: 7, 10, 13, 16, 19, 22, 25, 28 and 31, [B] is the intervening single-strand consisting of 3 to 23 nucleotides, and [A'] is the antisense strand comprising a complementary sequence to [A].
The double-stranded molecule of any one of claims 1 to 4, which contains one or two 3' overhangs.
A vector expressing the double-stranded molecule of any one of claims 1 to 5.
Vectors comprising each of a combination of a polynucleotide comprising a sense strand nucleic acid and an antisense strand nucleic acid, wherein the sense strand comprises of a sequence corresponding to a target sequence selected from among SEQ ID NOs: 7, 10, 13, 16, 19, 22, 25, 28 and 31, and has a length of between about 19 and about 25 nucleotides and the antisense strand nucleic acid consists of a sequence complementary to the sense strand, wherein the transcripts of the sense strand and the antisense strand hybridize to each other to form a doublestranded molecule, and wherein the vector, when introduced into a cell expressing a GPC3 gene, inhibits cell proliferation.
A composition for inhibiting a growth of GPC3 expressing cell and/or treating GPC3-related disease, which composition comprises at least one isolated double-stranded molecule inhibiting the expression of GPC3 and the cell proliferation, wherein the molecule is composed of a sense strand and an antisense strand complementary thereto, hybridized to each other to form the double-stranded molecule, or the vector(s) encoding thereof.
The composition of claim 8, which comprises the double-stranded molecule of any one of claims 1 to 5, or vector(s) of claim 6 or 7.
The composition of claim 8 or 9, wherein the GPC3-related disease is esophageal cancer, gastric cancer, hepatic cancer, osteosarcoma, soft tissue cancer or endometriosis.
The composition of any one of claims 8 to 10, wherein the composition comprises a transfection-enhancing agent and pharmaceutically acceptable carrier.
A method for inhibiting a growth of GPC3 expressing cell and/or treating GPC3-related disease, which method comprises the step of administering at least one isolated double-stranded molecule inhibiting the expression of GPC3 and the cell proliferation, wherein the molecule is composed of a sense strand and an antisense strand complementary thereto, hybridized to each other to form the double-stranded molecule, or the vector(s) encoding thereof.
The method of claim 12, wherein the double-stranded molecule is the double-stranded molecule of any one of claims 1 to 5.
The method of claim 12 or 13, wherein the GPC3-related disease is esophageal cancer, gastric cancer, hepatic cancer, osteosarcoma, soft tissue cancer or endometriosis.
The composition of any one of claims 12 to 14, wherein the double-stranded molecule or the vector is contained in a composition which comprises a transfection-enhancing agent and pharmaceutically acceptable carrier.