摘要：目的为研究肝癌中JST基因表达及其对HepG2细胞抑制作用,探索JST基因在肿瘤基因治疗中可能的作用.方法真核表达质粒pCMV-JST质粒转染入HepG2细胞系,该细胞系转染前不表达JST.转染方法为脂质体介导.细胞生长曲线,软琼脂集落形成能力及SCID鼠体内成瘤试验证实JST对HePG2的抑制作用.通过原位杂交及免疫组化检测了60对肝癌标本中JST mRNA、蛋白质表达.结果细胞生长曲线显示,转染HepG2细胞系生长慢于对照HepG2;软琼脂集落形成率前者为3.8%,后者为7.4%;SCID鼠体内成瘤(30.9±6.9)对(70.3±5.6),(P<0.01),证明转染HepG2细胞系致瘤能力下降.JST mRNA蛋白质表达水平在癌旁组织与正常组中高于肝癌组,(ISH:75%,70%对16.7%;IHC:66.7%,60%对10%,P<0.01).结论外源性JST基因对HepG2细胞显示强烈生长抑制作用.在肝癌组织中,JST显示下调表达,支持其在肝癌生长中抑制作用的结论,提示JST在肝癌基因治疗中可能起作用.%Objective To investigate the expression of metallothionein 1 (JST) gene in hepatocellular carcinoma tissue and the growth suppression effect of exogenous introduction of JST gene on liver cell line HepG2 and to explore the potential application of JST gene in gene therapy of tumor. Methods Eukaryotic expression vector of pCMV-JST plasmid was introduced into HepG2 line which expressed no JST protein originally with lipofectamine transfection method. The cell growth curve, soft agar colony formation rate and tumorigenicity in severe combined immunodeficient (SCID) mice were examined to demonstrate the growth suppression effect of exogenous JST gene on HepG2 cell line .The JST mRNA and JST protein were also detected in 60 pairs of srugical specimens of hepatocellular carcinoma by in situ hybridization and immunohistochemistry. Results The transfected HepG2 cell line grew more slowly than control HepG2 as shown by cell growth curves, the soft agar colony formation rate (3.8% vs 7.4% P<0.01) and the average growth rate of tumor in SCID mice (30.9±6.9 vs 70.3±5.6, P<0.01). The expression level of JST mRNA and protein significantly increased in paracancerous tissue, normal tissue, compared to in cancer tissues (75%, 70% vs 16.7% by in situ hybridigation and 66.7%, 60%vs 10.0% by immunohistochemistry, P<0.01). Conclusion Exogenous JST gene shows the strong effect of growth inhibition on HepG2 cell line. In the liver cancer tissue ,JST shows down-regulated expresssion that supports the inhibited function of JST in cancer growth and suggests JST may have an important role in gene therapy of hepatocellular carcinoma.
