胃癌组织中microRNA-650的表达及其生物学作用和临床意义

Role of MicroRNA-650 in Gastric Cancer and Its Clinical Significance

目的:研究microRNA-650(miR-650)在胃癌组织中的表达及其与胃癌细胞增殖、凋亡及转移的关系。方法:采用逆转录聚合酶链式反应(reverse transcription-polymerase chain reaction,RT-PCR)检测miR-650在胃癌组织标本及胃癌细胞株中的表达量,胃癌细胞株转染miR-650模拟剂以及miR-650抑制剂-LNA寡核苷酸后采用CCK-8试剂盒检测细胞增殖情况,采用流式细胞仪检测细胞凋亡情况,采用LC-MS/MS系统定量分析筛选miR-650靶蛋白,采用蛋白质印迹检测miR-650靶蛋白RGS7的表达水平。采用裸鼠异种移植模型验证miR-650对胃癌细胞的生物学作用及其抑制剂的生物疗效。结果:胃癌细胞株KATO III、NUGC4及SGC-7901高表达miR-650,而NCI-N87及MKN-45仅微量表达miR-650。在转染miR-650抑制剂-LNA寡核苷酸后胃癌细胞增殖水平显著下降,凋亡水平显著上升。G-蛋白信号调节因子7(regulator of G-protein signaling-7,RGS7)是miR-650下游靶点之一,靶蛋白RGS7表达水平与miR-650表达水平呈负相关,miR-650抑制剂可抑制肿瘤生长。结论:胃癌细胞株中miR-650的高表达可促进胃癌细胞增殖及转移并抑制其凋亡,机制可能是通过抑制靶蛋白RGS7的表达。

Objective：To explore the role of microRNA 650（miR-650） in the development and prognosis of gastric cancer and its clinical significance. Methods：Real time quantitative reverse transcription-polymerase chain reaction was used to detect miR- 650 expression levels in five gastric cancer cell lines and gastric cancer tissues. After the miR-653 mimic and inhibitor were transfected into gastric cancer cells, the cellular growth activity was estimated by CCK 8 kit; the apoptosis activity was tested by flow cytometry; the candidate targets of miR-650 were analysed using the LC MS/MS-based te：hniques; western blot was used to test the expression levels of reglator of G-protein signaling 7（RGS7） which acted as a target of miR 650 in gastric canc er cells. Nude mouse xenograft model was used to explore the biological effect of miR-650 in gastric cancer cells and the cura tive effect of miR 650 inhibitor. Results： High levels of miR-650 have been detected in KATO III, NUGC4 and SGC-7901 gas- tric cancer cell lines, while NCI-N87 and MKN-45 gastric cancer cell lines only displayed low expression levels of miR-650. Af ter transfection of LNA inhibitor, gastric cancer cell lines proliferation was significantly inhibited, while apoptosis was promo- ted. RGS7 was one of the functional downstream targets of miR 650, and the expression level of RGS7 was inversely correlated with the expression level of miR-650. MiR-650 inhibitor can suppress tumor growth. Conclusions： The up-regulation of miR- 650 promotes proliferation, metastasis and inhibits apoptosis of gastric cancer cells, and possibly through suppressing the ex- pression of RGS7.