人肝癌细胞系HCCLM3中生长抑素受体亚型的表达研究

目的检测人肝癌高转移细胞系生长抑素受体mRNA和蛋白的表达,探讨生长抑素对肝癌细胞株增殖的影响及其作用机制.方法应用免疫组化和RT-PCR的方法检测人肝癌细胞系中五种生长抑素受体亚型的表达,并进行半定量分析;应用MTT法检测8肽生长抑素对肿瘤细胞增殖的影响.结果肝癌细胞HCCLM3中存在SSTR1-5表达.生长抑素抑制肝癌细胞株HCCLM3的增殖并呈浓度依赖性,其作用可以被PTP抑制剂正钒酸钠所抑制;HCCLM3细胞表达5种生长抑素受体的mRNA和蛋白,表达强度由强到弱依次为SSTR2、SSTR1、SSTR4、SSTR3、SSTR5.SSTR2和SSTR1的表达强度明显强于SSTR3、SSTR4、SSTR5（P＜0.05）,应用生长抑素后受体亚型SSTR2、SSTR3、SSTR5 mRNA表达强度明显高于SSTR1、4 mRNA（P＜0.05）.结论五种生长抑素受体亚型均存在于HCCLM3肝癌细胞系中,生长抑素可以明显抑制肝癌细胞的增殖.SSTR2 SSTR3、SSTR5和生长抑素结合后通过激活PTP抑制肿瘤细胞的生长和增殖.

The differential expression of somatostastin receptors in hepatocellular carcinoma HCCLM3 cell lines

Objective To investigate the mRNA and protein expression of somatostatin receptors in hepatocellular carcinoma HCCLM3 cell lines and to explore the mechanism by which somatostatin effects on hepatocellular carcinoma. Methods RT-PCR., immunocytochemistry and MTT were used to detect mRNA and protein expression of somatostatin receptors in hepatocellular carcinoma cells and evaluate the antiproliferative effect of somatostatin. Results The effect of somatostatin on the cellular proliferation was verified. Immunocytochemistry study revealed a mainly intracellular distribution of all SSTRs with unique patterns for each of them. mRNA expression of all 5 subtypes of somatostatin receptors was different, SSTR2 and SSTR1 mRNA expressions were significantly higher than SSTR3, SSTR4 and SSTR5 ( P < 0. 05 ). Conclusion All 5 subtypes of somatostatin receptors exist in hepatocellular carcinoma HCCLM3 cell lines. Cell proliferation is reduced by somatostatin and SSTR2,3,5 via a protein tyrosine phosphatase dependent mechanism.