Glypican‐3 is overexpressed in human hepatocellular carcinoma

Abstract

To identify candidate genes that could be used as diagnostic and therapeutic targets for hepatocellular carcinoma (HCC), we searched for the genes that are overexpressed in HCC by combining representational difference analysis and microarray. Genes such as glypican-3 (GPC3), insulin-like growth factor 2, long-chain fatty-acid-coenzyme A ligase 4, farnesyl diphosphate synthase were frequently identified in our screening. Northern blot analysis with these four genes confirmed their overexpression in HCC. Among them we found that GPC3 transcript is upregulated in six out of seven cases of HCC. Immunoblot and immunohistochemical staining using polyclonal anti-GPC3 antibodies further confirmed that GPC3 protein is indeed increased in HCC tumor samples. We also found that GPC3 is secreted into culture media from cell lines derived from HCC. We conclude that GPC3 is a good molecular marker for HCC. (Cancer Sci 2003; 94: 259-262) lypican-3 (GPC3) is a member of the glypican family of heparan-sulfate proteoglycans, which are linked to the cell surface through a glycosylphosphatidylinositol anchor.1) GPC3 loss-of-function mutation in human causes type 1 Simpson-Golabi-Behmel syndrome (SGBS1), an X-linked condition characterized by pre-and postnatal overgrowth.2) GPC3 knockout mice indeed exhibited several phenotypic features of SGBS1. [3][4][5] These findings together with cell line-specific promotion of apoptosis by OCI-5/GPC3 6) suggest that GPC3 plays a negative role in cell proliferation and an apoptosis-inducing role in specific tissues.Consistent with the above idea, GPC3 expression is frequently silenced by promoter methylation in ovarian cancer cell lines, 7) rat mesothelioma cell lines and human primary tumors, 8) and breast cancer cell lines. 9) In addition, ectopic expression of GPC3 inhibited growth in some of the above cell lines, suggesting a tumor-suppressive role of GPC3. In contrast, GPC3 is known to be overexpressed in hepatocellular carcinoma, 10,11) neuroblastoma and Wilms' tumor cells.12) The role of GPC3 in these tumors is not known. It is also not known whether GPC3 protein is indeed increased in these tumors.Hepatocellular carcinoma (HCC) is one of the most common tumors worldwide and is one of the leading causes of death among cancer patients in Korea. Identification of genes that are overexpressed in HCC not only helps our understanding of tumorigenesis, but also helps to develop diagnostic and therapeutic targets. In this study, we combined representational difference analysis (RDA) 13) and microarray 14) to identify genes that are frequently overexpressed in HCC tumor samples. Since GPC3 was the most frequently obtained gene in our screening, we further evaluated it as a tumor marker for HCC. Materials and MethodsTumor samples and cell lines. HCC tumor tissues and corresponding normal liver tissues were obtained from patients (Table 1) undergoing surgery in Kyungpook National University Hospital (Daegu, Korea) with the approval of the human research review committee and the patients' consent. C...

Pathologic diagnosis of early hepatocellular carcinoma: A report of the international consensus group for hepatocellular neoplasia

“…[34][35][36][37][38][39] GPC3 immunoreactivity has a reported sensitivity of 77% and specificity of 96% in the diagnosis of small HCC; therefore, GPC3 positivity is a strong argument for malignancy. 40,41 The staining pattern is usually cytoplasmic but may be membranous or canalicular (Fig.…”

Transcriptomic and genomic analysis of human hepatocellular carcinomas and hepatoblastomas

“…Several recent studies have shown that Glypican 3 is overexpressed uniquely in HCC. [8][9][10][11] GPC3 is a member of a family of six proteins which are anchored to the plasma membrane by GPI linkage and bind heparin sulfate proteoglycans. GPC3 regulates availability of Wnt proteins.…”

Diagnostic value of HSP70, glypican 3, and glutamine synthetase in hepatocellular nodules in cirrhosis

“…12 The gene is frequently methylated in various tumors and cell lines, [13][14][15] suggesting a tumor-suppressive role in tumorigenesis. However, it is also overexpressed in HCC; 16 recently, both Sung et al 17 and Capurro et al 5 reported GPC3 overexpression in HCC both at messenger and protein level. By using a home-made antibody, Yamaouchi et al 18 reported GPC3 weak and focal staining in HCC precursor lesions but diffuse staining in the vast majority of HCCs.…”