自噬及自噬性细胞死亡抑制紫杉醇诱导的胃癌细胞凋亡

目的明确自噬和自噬性细胞死亡在胃癌SGC-7901及BGC-823细胞紫杉醇处理过程中的存在,探讨其对紫杉醇诱导的凋亡敏感性的作用。方法流式细胞仪和MTT法分别检测紫杉醇诱导SGC-7901及BGC-823细胞的凋亡率和总死亡率,死细胞DAPI染色荧光显微镜检测非凋亡性细胞死亡,吖啶橙染色流式细胞仪和荧光显微镜分别定量、定性检测自噬和自噬性细胞死亡的存在,自噬特异性阻断剂3-甲基腺嘌呤和紫杉醇共同作用细胞后流式细胞术检测细胞死亡率和凋亡率的变化。结果紫杉醇处理SGC-7901及BGC-823细胞早期(24h内)可出现明显的细胞自噬性变化,自噬高峰期出现紫杉醇诱导3~6h,自噬性细胞死亡存在并可能是紫杉醇诱导的非凋亡性细胞死亡的主要形式,抑制紫杉醇诱导的细胞自噬可以促进紫杉醇诱导细胞凋亡的发生。结论紫杉醇可以诱导胃癌SGC-7901及BGC-823细胞自噬及自噬性细胞死亡,并且紫杉醇诱导的胃癌细胞自噬会拮抗胃癌细胞凋亡的发生,从而为胃癌化疗耐受提供新的解释,可能为胃癌治疗提供新的途径。

Autophagy protects human gastric cancer cells from apoptosis induced by the microtubule-targeting agent Taxol

Objective To study the exist of Taxol-induced autophagy and autophagic cell death in SGC-7901/BGC-823 cell lines, and to study the role to the sensibility of apoptosis induced by Taxol.Methods Taxol-induced apoptosis rates and cell death rates were determined by flow cytometry and tetrazolium bromide(MTT)colorimetry, respectively. The non-apoptosis cell death was observed after DAPI stain using fluorescent microscopy. Autophagy and autoghagic cell death were detected after acriding orange stain using flow cytometry and fluorescent microscopy. The relationship between autophagy and apoptosis were assayed by 3-MA/ Taxol co-treatment, for 3-MA is the specific inhibitor of autophagy.Results The autophagic vacuoles were greatly increased after Taxol treated in SGC-7901/BGC-823, the peak of autophagy occured at 3~6 h after Taxol treatment, and inhibiting Taxol-induced autophagy could promote apoptosis. Taxol-induced autophagic cell death was observed through acriding orange stain in dead cells.Conclusion Taxol can induce autophagy and autophagic cell death in SGC-7901/BGC-823, there is cross-talk between the Taxol-induced autophagy and apoptosis, that is the autophagy can inhibit the occur of apoptosis.