Beclin 1非自噬依赖性增加OVCAR3细胞对蛋白酶体抑制剂的敏感性研究

Enhancing effect of Beclin 1 on cytotoxicity of OVCAR3 cells induced by proteasome inhibitors in autophagyindependent manner

目的探讨Beclin 1对蛋白酶体抑制剂抗卵巢癌OVCAR3细胞作用的影响及其机制探讨。方法 2011年10月至2012年4月在中国医科大学附属盛京医院对OVCAR3细胞经不同浓度MG132处理24h后,MTT法检测细胞存活率。空质粒或Beclin 1质粒转染OVCAR3细胞后,不同蛋白酶体抑制剂处理24 h后,MTT法检测细胞存活率。采用sh RNA技术下调OVCAR3细胞的早期自噬关键基因Atg7或采用晚期自噬抑制剂氯喹及巴弗洛霉素A1处理OVCAR3细胞,MTT法检测MG132对细胞的毒性作用。结果与空白对照组比较,1、2、5和10μmol/L浓度的MG132作用24h均能明显抑制OVCAR3细胞的生长,P值分别为0.023、0.005、0.001、0.000,且呈浓度依赖性;与空质粒转染组相比,Beclin 1转染组OVCAR3细胞经硼替佐米、环氧甲酮四肽、乳胞素、MG132四种蛋白酶体抑制剂处理后,细胞存活率差异均有统计学意义下降,P值分别为0.003、0.008、0.006、0.000。与未转染组和空质粒转染组相比,sh Atg7转染组OVCAR3细胞经MG132处理后,细胞存活率差异无统计学意义,P值分别为0.468,0.667。与空白对照组比较,氯喹及巴弗洛霉素A1处理组OVCAR3细胞经MG132处理后,细胞存活率差异无统计学意义,P值分别为0.776,0.802。结论 Beclin 1以不依赖于自噬的方式增加卵巢癌OVCAR3细胞对蛋白酶体抑制剂的敏感性。

Objective To investigate the effect and mechanism of Beclin I on cytotoxicity of OVCAR3 cells mediated by proteasome inhibitors. Methods OVCAR3 ceils were treated with the indicated concentration of MG 132 for 24h and cell viability was measured using MTT assay. OVCAR3 ceils were transfected with mock or Beclin 1 eukaryotic plasmid, then were treated with the indicated proteasome inhibitors;cell viability was measured using MTT assay. OVCAR3 eells were transfected with shAtgT, the key factor of autophagy at early stage, or cotreated with autophagy inhibitors at late stage, then MTT assay was used to investigate the cytotoxicity of OVCAR3 cells induced by MGI32. Results 1,2,5 and 10 μmol/L MGI32 resulted in suppression of cell growth of OVCAR3 in concentration-dependent manner,P was 0.023, 0.005,0.001 and 0.000. Overexpression of Beclin 1 enhanced the cytotoxicity of OVCAR3 cells mediated by the indieated proteasome inhibitors;P was 0.003,0.008,0.006 and 0.000. Compared with untransfected and control transfected groups, downregulation of autophagy transfected with shAtg7 demonstrated no obvious effect on cytotoxicity of OVCAR3 cells induced by MG132;P was 0.468, 0.667. Cotreated with chloroquine or bafilomycin A1, both demonstrated no obvious effect on cytotoxieity of OVCAR3 （,.ells induced by MG132;P was 0.776 and 0.802.Conclusion Beclinl en- hances the eytotoxieity of OVCAR3 cells mediated by pro- teasome inhibitors in autophagy-independent manner.