BNIP3影响自噬水平对胃癌的影响

Effect of BNIP3-induced autophagy in gastric carcinoma

目的探讨BNIP3蛋白表达在肿瘤低氧环境中对胃癌的作用及探讨其影响自噬水平的机制。方法胃癌手术标本取材18例,分别通过免疫组化和免疫印迹检测BNIP3和LC3的蛋白表达水平在癌组织和正常组织中的差异;培养中分化的人胃癌细胞系SGC-7901,在氯化钴(CoCl2)引发的低氧环境中,观察BNIP3 siRNA干扰后对自噬相关蛋白LC3的表达变化,以及使用自噬阻滞剂3-甲基腺嘌呤(3-methyladenine,3-MA)后对细胞活力的影响。结果免疫组化和免疫印迹检测中均可见肿瘤组织BNIP3蛋白表达量较正常组织增高,同时肿瘤组织中LC3-II表达水平也明显上调。BNIP3siRNA使胃癌细胞SGC-7901中LC3-Ⅱ蛋白表达下调,而且自噬水平降低后,在低氧环境中细胞活力明显提高。结论BNIP3蛋白能够通过调控自噬水平对胃癌细胞在乏氧环境中细胞死亡发挥重要的作用。

Aim To study the effect of BNIP3 on hy-poxia-induced autophagic cell death in gastric carcino-ma.Methods The protein levels of BNIP3 and LC3-Ⅱ of 1 8 cases of gastric carcinoma were studied with immunocytochemistry and Western blot analysis be-tween normal and tumor tissues.The expression of LC3-Ⅱ in SGC-7901 cells was assessed while knock-down of BNIP3 by siRNA in CoCl2-induced hypoxia, and the effect of 3-MA was also studied.Cell viability in hypoxia treatment for 48 h was estimated with cell counting kit-8 （CCK8）.Results Compared with nor-mal tissues,the protein levels of BNIP3 and LC3-Ⅱwere increased in tumor tissues.BNIP3 siRNA could decrease the expression of LC3-Ⅱ and enhance the cell viability,while inhibition of autophagy could also in-crease the cell viability in SGC-7901 cells.Conclu-sions BNIP3 may play a role in hypoxia-induced cell death in gastric carcinoma,and the possible mecha-nism may be related to the regulation of autophagy.