let-7a调控自噬对缺氧状态卵巢癌HO-8910细胞增殖的影响  

Effect of autophagy regulated by let-7a on cell proliferation of hypoxic ovarian cancer HO-8910 cells

作　　者：陈国庆[1] 王晨虹[1] 刘力华[1] 王忠[1] 朱雄珊 

机构地区：[1]深圳市妇幼保健院产科,广东深圳518028

出　　处：《中华肿瘤防治杂志》2015年第22期1741-1746,共6页Chinese Journal of Cancer Prevention and Treatment

基　　金：深圳市卫生计生系统博士创新项目(201505012)

摘　　要：目的自噬是细胞在不良环境中自我吞噬的生物学现象,在恶性肿瘤发病机制中具有重要作用,缺氧是诱导细胞自噬的重要因素。本研究探讨不同氧环境中卵巢癌HO-8910细胞let-7a的表达变化及对缺氧细胞自噬、增殖的影响。方法实验分常氧组、缺氧组、缺氧+miR-NC-mimics组和缺氧+let-7a-mimics组4组,各组细胞经处理48h后:吖啶橙染色观察细胞自噬发生情况;MTT法分析细胞增殖变化,流式细胞术检测细胞周期分布;Real time PCR分析let-7a、Beclin-1和LC3-Ⅱ的表达变化,蛋白质印迹试验分析Beclin-1和LC3-Ⅱ蛋白表达变化。结果 HO-8910细胞经缺氧处理后自噬率显著增高至(34.46±5.13)%,F=49.932,P=0.002;在缺氧基础上转染miR-NC-mimics后,自噬率变化不大,F=0.110,P=0.756;而转染let-7a-mimics后,细胞自噬率显著降低至(4.56±2.04)%,F=68.186,P<0.001。缺氧使G0/G1期细胞数量明显增至(70.43±3.19)%,F=23.216,P=0.008;同时转染miR-NC-mimics后,其数量变化差异无统计学意义,F=0.467,P=0.532;而在缺氧条件下转染let-7a-mimics,其数量则增至(82.37±3.45)%,F=67.423,P=0.001;并伴随细胞增殖抑制率显著上升,F=24.602,P=0.007。缺氧条件下以及缺氧同时转染miR-NC-mimics后,let-7a表达下调,而Beclin-1、LC3-Ⅱ表达上调;而在缺氧基础上转染let-7a-mimics后,let-7a表达明显增强,F=295.623,P<0.001;Beclin-1蛋白表达下调,F=33.285,P=0.002;LC3-Ⅱ也明显下调,F=41.969,P=0.001。结论卵巢癌HO-8910细胞在缺氧状态时,let-7a表达下调,细胞启动适度自噬保护机制,介导细胞逃避缺氧环境使细胞继续快速生长,当上调let-7a表达后,缺氧所致的适度自噬保护作用被消减,细胞增殖明显受抑。OBJECTIVE Autophagy is a biological phenomena of cell eating their own in a poor environment for the growth, which plays an important role in the pathogenesis of malignant tumor. Hypoxia is one of the important factors that induces autophagy. The present study was to explore the expression of let-7a and its effect of autophagy and cell proliferation on ovarian cancer HO-8910 cells under different oxygen environments. METHODS The experiment was divided into normoxic group, hypoxia group, hypoxia＋ miR-NC-mimics group, hypoxia＋ let 7a-mimics group, each group of cells were treated at 48 h. Autophagy was detected by acridine orange staining. Cell proliferation was analyzed by MTT assay. Cell cycle distribution was determined by flow cytometry. The expression of let-7a, mRNA of Beclin-1 and LC3- Ⅱ were detected by Real time PCR. The expressions of protein of Beclin-1 and LC3- Ⅱ were analyzed by Western blot. RESULTS Autophagy rate was significantly increased to （34.46±5.13） % （F=49. 932, P=0. 002） after treating With hypoxia in HO-8910 cells, autophagy rate changed little on the basis of the hypoxic transfected miR-NC-mimics （F=0. 110, P=0. 756）, but after transfecting let-7a-mimics autophagy was significantly reduced to （4.56±2.04）% （F=68. 186, P〈0. 001）; hypoxia resulting in G0/G1 phase cell numbers significantly increased to （70.43 ±3.19）% （F=23. 216, P= 0. 008）, while transfecting miR-NC-mimics change their number was not statistically significant （F=0. 467 ,P=0. 532）, under hypoxic conditions transfecting let-7a-mimics their number increased to （82.37±3.45）%（F=67. 423 ,P=0. 001）, with the proliferation inhibition rate increased significantly （F= 24. 602, P=0. 007）. Expression of let-7a of HO-8910 cells was downregulation but Beclin-1 and LC3-Ⅱ were upregulation under hypoxic conditions, and hypoxia simultaneously transfecting miR-NC-mimics. However, expression of let-7a was significantly enhanced（F=295. 623,P〈0. 001）while under hypoxic conditions t

关 键 词：细胞自噬 缺氧性细胞损伤 细胞凋亡 let-7a 卵巢癌 

分 类 号：R737.31[医药卫生—肿瘤]