过表达microRNA-7对人肺癌95D细胞凋亡的影响

目的 探讨过表达microRNA-7对人肺癌95D细胞体内外凋亡的作用。方法 将miR-7真核表达载体（命名为p-miR-7）体外瞬时转染人肺癌95D细胞，利用TUNEL法观察95D细胞凋亡的变化；免疫荧光技术检测各组细胞磷酸化Caspase3和Caspase9蛋白的表达；建立人肺癌裸鼠模型，肿瘤局部注射p-miR-7后利用TUNEL法检测肿瘤局部细胞凋亡变化，同时，免疫组织化学法检测凋亡相关的磷酸化Caspase3和Caspase9蛋白的表达变化。结果 体外转染p-miR-7后可导致人肺癌细胞的凋亡（P<0.05）。同时，细胞中磷酸化Caspase3和Caspase9蛋白水平显著增加（P<0.05）；肿瘤局部注射p-miR-7后，肿瘤局部miR-7表达水平及细胞凋亡也明显增强（P<0.05），磷酸化Caspase3和Caspase9蛋白水平也显著增加。结论 过表达miR-7可以导致肿瘤细胞凋亡，这与凋亡相关蛋白Caspase3和Caspase9磷酸化水平增加有关。

Effect of microRNA-7 Overexpression on Apoptosis of Human Lung Cancer Cell Line 95D

Objective To investigate the effect of microRNA-7 overexpression on the apoptosis of human lung cancer cell line 95D in vitro and in vivo. Methods Eukaryotic expression vector encoding miR-7 (termed as p-miR-7) was transiently transfected into human lung cancer cell line 95D. TUNEL method was conducted to observe cell apoptosis. The phosphorylation of Caspase3 and Caspase9 protein were detected by immunofluorescence technology. Plasmid p-miR-7 was locally injected into tumor mass in nude mice model bearing human lung cancer cell line 95D. Then, cell apoptosis was detected by Hematoxylin and eosin staining and TUNEL method, respectively. Moreover, phosphorylation levels of Caspase3 and Caspase9 protein were determined by immunohistochemistry assay. Results miR-7 overexpression could lead to the apoptosis of lung cancer cells in vitro (P<0.05), accompanied by the increased phosphorylation levels of Caspase3 and Caspase9 proteins(P<0.05). After local injection of p-miR-7, both the expression level of miR-7 and the apoptosis of tumor cells were increased significantly(P<0.05). Moreover, phosphorylation levels of Caspase3 and Caspase9 protein were increased obviously(P<0.05). Conclusion miR-7 overexpression could lead to tumor cell apoptosis in vitro and in vivo, which is associated with increased phosphorylation levels of  apoptosis related proteins Caspase3 and Caspase9.