微小RNA-122对肝癌细胞迁移和侵袭的影响以及相关机制

Effects and mechanisms of microRNA-122 on invasion and migration of hepatoceHular carcinoma cells

目的检测微小RNA-122（miR-122）在肝癌中的表达，探讨其在肝癌细胞侵袭与迁移中的作用及机制。方法实时荧光定量聚合酶链反应（RT-PCR）检测肝癌组织、癌旁组织、正常肝细胞、肝癌细胞系中miR-122的表达，通过转染升高或抑制肝癌细胞系中miR-122的表达，Transwell实验分析其对肝癌细胞侵袭与迁移的影响，蛋白印迹（western blot）检测相关机制蛋白表达量，包括胰岛素样生长因子-1受体（IGF-1R）、E-钙黏蛋白（E-cadherin）、波形蛋白（vimentin）。结果肝癌组织中miR-122表达水平低于癌旁组织[（20．5±4．2）×10^-4比（30．3±5．6）×10^-4]；与HBV（-）组比较，HBV（＋）组肝癌组织miR-122表达降低更为明显[（25．6±3．5）×10^-4比（19．1±3．2）×10^-4]。几种肝癌细胞系中，MHCC-97H的miR-122表达降低最为明显[（33．7±1．3）×10^-3]，SMMC-7721表达相对较高[（65．3±1．3）×10^-3]。与各自阴性对照比较，过表达miR-122抑制MHCC-97H侵袭与迁移[（218．7±24．0）个比（418．0±23．4）个，（392．7±12．8）个比（706．6±19．8）个]；抑制miR-122表达促进SMMC-7721侵袭和转移[（233．0±14．4）个比（145．0±8．0）个，（561．3±9．6）个比（218．0±11．3）个]。Western blot实验结果显示升高miR-122表达抑制IGF-1R、Vimentin表达，促进E—cadherin表达。结论miR-122在肝癌组织中表达降低，HBV（＋）肝癌组织中降低更为明显，miR-122可通过IGF-1R调控上皮-间质转化抑制肝癌的侵袭与迁移，miR-122可能为肝癌的治疗提供新的靶点。

Objective To detect the expression of miR-122 in hepatocellular carcinoma （HCC） cells and tissues, and to explore the role and the underlying mechanisms of miR-122 in HCC cells on invasion and migration. Methods Real-time quantitative polymerase chain reaction of analysis was used to examine the expression of miR-132 in HCC cell lines, a normal liver cell line, HCC tissues and adjacent nontumor tissues. Over express or inhibit miR-122 by transfection. The invasion and migration of HCC cells were analyzed by Transwell assays. Meanwhile, related mechanism proteins were detected by western blot, including insulin like growth factor 1 receptor（ IGF-1 R）, E-cadherin, vimentin. Results The expression of miR-122 was decreased in HCC tissue samples compared with the adjacent non-tumor tissues [ （20. 5 ± 4. 2 ） ×10^-4 vs, （30. 3 ±5.6） ×10^-4], especially in HCC tissue samples with HBV[ （25.6±3.5）×10^-4 vs. （19.1±3.2） ×10^-4]. The same results were observed in HCC cell lines. MHCC-97H cells exhibited lowest level of miR-122 expression [ （33.7 ±1.3 ）×10^-3 ], whereas SMMC-7721 exhibited the highest level of miR-122 expression [ （65.3±1.3）×10^-3]. MiR-122 over-expression suppressed the invasion and mi- gration of MHCC-97H [ （218.7 ±24. 0） vs. （418.0 ± 23.4）, （392. 7 ± 12. 8 ） vs. （706. 6± 19. 8） ]. Knocking down miR-122 promoted the invasion and migration of SMMC-7721 [ （233.0 ± 14.4 ） vs. （ 145.0 ± 8. 0）, （561.3 ± 9. 6） vs. （218.0 ± 11.3） ]. Western blot revealed that miR-122 suppressed the expression of IGF-1 R, Vimentin and facilitated the expression of E-cadherin. Conclusions The study indi- cates that miR-122 is downregulated in HCC, especially in HCC tissue samples with HBV. MiR-122 can suppress invasion and migration of hepatocellular carcinoma by regulating IGF-1 R and epithelial mesenchy- mal transition, and may provide a new therapeutic option for HCC.