BNIP3介导的线粒体自噬对低氧环境下卵巢癌HO-8910PM细胞侵袭转移的影响

Effects of mitophagy mediated by BNIP3 on invasion and metastasis of ovarian cancer HO-8910PM cells under hypoxia

目的探讨常氧及低氧条件下卵巢癌HO-8910PM细胞线粒体外膜蛋白B淋巴细胞瘤-2基因/腺病毒E1B相互作用蛋白3(BNIP3)的表达变化及其对线粒体自噬和细胞侵袭转移的影响。方法将人高转移性卵巢癌细胞株HO-8910PM分为常氧组、低氧组、低氧+BNIP3 siRNA组,各组细胞处理48 h后,应用吖啶橙染色及透射电镜观察细胞线粒体自噬的变化;划痕实验及Transwell小室检测细胞迁移和侵袭能力的改变;实时荧光定量PCR(qPCR)和Western blot分析BNIP3、自噬微管相关蛋白轻链3-Ⅱ(LC3-Ⅱ)的基因及蛋白表达变化。结果在低氧条件下,吖啶橙染色结果显示HO-8910PM细胞线粒体自噬率显著增加,透射电镜结果显示HO-8910PM细胞线粒体自噬小体显著增多(P<0.01)。转染BNIP3 siRNA后细胞线粒体自噬、细胞迁移率和侵袭率均显著受抑(P<0.01)。低氧组BNIP3、LC3-Ⅱ的mRNA和蛋白表达明显增高,低氧条件下转染BNIP3 siRNA后BNIP3、LC3-Ⅱ的mRNA和蛋白表达明显下调(P<0.01)。结论在低氧条件下抑制卵巢癌HO-8910PM细胞BNIP3的表达可显著抑制线粒体自噬,降低细胞迁移和侵袭能力。

Objective To investigate the expression of B-cell lymphoma-2/Adenovirus E1B interacting protein 3(BNIP3)of ovarian cancer HO-8910PM cells under normal and hypoxic conditions and its effects on mitophagy,cell invasion and metastasis.Methods The human highly metastatic ovarian cancer cell line HO-8910PM was divided into three groups:normoxia group,hypoxia group and hypoxia+BNIP3 siRNA group.After 48 hours of treatment,mitophagy was detected by acridine orange staining and transmission electron microscopy.Migration and invasion of HO-8910PM cells were determined by scratch test and Transwell chamber assay.The mRNA and protein expressions of BNIP3 and LC3-Ⅱwere analyzed by qPCR and Western blot assay.Results Under low oxygen conditions,acridine orange staining showed a significant increase in the incidence of mitophagy in HO-8910PM cells,and transmission electron microscopy showed a significant increase in the number of mitochondrial autophagy of HO-8910PM cells(P<0.01).After transfection of BNIP3 siRNA,mitochondrial autophagy,cell migration and invasion were significantly inhibited(P<0.01).The mRNA and protein expressions of BNIP3 and LC3-Ⅱwere significantly increased in hypoxia group,which decreased significantly after transfection of BNIP3 siRNA under hypoxia(P<0.01).Conclusion The inhibition of BNIP3 expression in HO-8910PM cells under hypoxia can significantly inhibit mitophagy and reduce cell migration and invasion.