自噬在长春瑞滨诱导的肺癌细胞A549死亡中的作用

背景与目的已有的研究表明,很多药物可以诱导肿瘤细胞发生自噬。本研究旨在明确自噬在肺癌A549细胞长春瑞滨处理过程中的存在,研究自噬在长春瑞滨诱导的A549细胞死亡中的作用。方法MTT法检测细胞生存率;激光共聚焦显微镜和流式细胞仪分别定性及定量检测自噬特异性蛋白LC3的表达;AnnexinV-FITC流式细胞术检测细胞凋亡;自噬特异性阻断剂3-甲基腺嘌呤和长春瑞滨共同作用细胞后用MTT法和流式细胞术检测细胞死亡率和凋亡率的变化。结果长春瑞滨处理肺腺癌细胞早期(24h内)可出现明显的自噬性变化,自噬高峰期出现在长春瑞滨诱导(6-12)h,在长春瑞滨给药前阻断自噬,长春瑞滨对A549细胞的毒性作用增强,而在其给药后阻断自噬则长春瑞滨对A549细胞的细胞毒性作用有所减弱。结论长春瑞滨可以诱导肺癌A549细胞自噬,在长春瑞滨给药前期,自噬对细胞有保护作用,可以延迟凋亡的发生;而在长春瑞滨给药后期,自噬则作为一种细胞的的死亡程序,与凋亡一起促进细胞死亡。

The role of autophagy in human lung cancer cell line A549 induced by Vinorelbine

Background and objective It has been proven that many kinds of drug could induce autophagy in tumor cells. The aim of the study is to verify whether Vinorelbine could induce autophagy in A549 cell lines, and to investigate the role in the effectiveness of death induced by Vinorelbine. Methods Cells survival rate was examined by tetrazolium bromide (MTT) colorimetry; interactive laser microscopy and flow cytometry were used to detect LC3 expression levels qualitatively and quantitatively, respectively; apoptosis rates were checked by flow cytometry; treatment of A549 cells with 3-MA and Vinorelbine, the apoptosis rates and cell death rates were examined by flow cytometry. Results In the early (<24 h), autophagy was evident. The crest-time appeared at (6-12) h after the cells treated with Vinorelbine. The specific inhibitor of autophagy 3-MA exerted opposite effects on Vinorelbine-induced death of A549cells: 3-MA potentiated Vinorelbine,s cytotoxicity in A549 cells when administered 1 h before Vinorelbine; while it attenuated Vinorelbine-induced death of A549 cells when treated 1 h after Vinorelbine. Conclusion Vinorelbine can induce autophagy in A549. In the early, autophagy could delay apoptosis. However, in the end, autophagy promoted cell death.