microRNA-616在肝细胞癌侵袭转移中的作用机制研究

目的探讨microRNA-616（miR-616）在肝细胞癌（HCC）中的表达及其在HCC侵袭转移中的作用机制。方法通过qRT-PCR检测miR-616在60例HCC及癌旁组织中的表达，同时检测miR-616在不同肝癌细胞系中的表达情况；免疫组织化学染色检测miR-616在HCC及癌旁组织中波形蛋白（vimentin）、上皮型钙黏素（E-cadherin）及同源性磷酸酶-张力蛋白（PTEN）的表达情况；qRT-PCR检测miR-616在人正常永生化肝细胞（LO2）及5种不同肝癌细胞系（HepG2、SMMC-7721、Hep3B、Hu7）中的表达水平；使用miR-616抑制物作用Hep3B细胞，TranswellTM实验检测miR-616抑制后Hep3B细胞侵袭能力变化；应用miR-616抑制物及PTENsiRNA转染Hep3B细胞，qRT-PCR检测Hep3B中miR-616、vimentin、PTEN、E-cadherin的mRNA水平，Westernblot法检测癌细胞中vimentin、PTEN、E-cadherin的蛋白水平。结果miR-616在HCC组织中表达水平高于对应癌旁组织；miR-616在不同肝癌细胞系中表达均高于LO2细胞；miR-616高表达与低表达在血管侵犯、Edmonson-Steiner分级、TNM分期比较差异均有统计学意义(均P＜0.05)；miR-616高表达肝癌组PTEN及E-cadherin水平低于miR-616低表达肝癌组，而vimentin水平高于miR-616低表达肝癌组，相关性分析结果显示HCC组织中miR-616与E-cadherin、PTEN水平呈负相关，与vimentin水平呈正相关；在肝癌细胞中抑制miR-616后PTEN及E-cadherin表达水平上调，而vimentin表达降低，Hep3B细胞的侵袭能力明显降低。结论miR-616在HCC组织中表达上调，其表达与HCC恶性临床病理特征有关，miR-616促进肝癌细胞侵袭转移的作用可能与其抑制PTEN表达及诱导上皮间质转化有关。

Expression of miR-616 in human hepatocellular carcinoma and its effect on tumor invasion and metastasis

Objective To investigate the expression of miR-616 in human hepatocellular carcinoma and its effects on tumor invasion and metastasis. Methods The expression of miR-616 was detected with real-time quantitative PCR (qRT-PCR) in 60 specimens of hepatocellular carcinoma (HCC) tissues and corresponding adjacent normal tissues; and also in human HCC HepG2, SMMC-7721, Hep3B, Hu75 cells and normal liver LO2 cells. The expression of vimentin, phosphatase, tensin homolog (PTEN) and E-cadherin was detected with immunohistochemical S-P method. The miR-616 inhibitor was transfected into Hep3B cells in vitro, cell invasion was analyzed by Transwell? assay. The expression of PTEN, E-cardhern and vimentin mRNAs and proteins after transfection was detected by qRT-PCR and Western blotting, respectively. Results The expression of miR-616 in HCC tissues was higher than that in matched tumor-adjacent normal tissues; and it was significantly correlated with venous infiltration, high Edmondson-Steiner grades and lymph node metastasis and TNM tumor stages in HCC. Elevated miR-616 expression was observed in HCC cell lines HepG2, SMMC-7721, Huh7 and Hep3B as compared with that in LO2 hepatic cell line. Furthermore, miR-616 expression was negatively correlated with E-cadherin and PTEN, positively correlated with vimentin in HCC tissues. The miR-616 inhibitor suppressed the migration and invasion in Hep3B cells; and it increased the expression of E-cadherin and PTEN, while decreased the expression of vimentin in Hep3B cells. In addition, down-regulation of PTEN'' expression partially abrogated the effect of miR-616 inhibitor in HCC cells. Conclusion The expression of miR-616 in HCC tissues is significantly up-regulated, and it can promote proliferation and induce apoptosis of HCC cells by down-regulating the expressions of PTEN.