川楝素下调ATF2蛋白的表达增强顺铂对肺癌细胞的凋亡诱导活性研究

目的 探讨川楝素辅助治疗是否能增强顺铂对肺癌细胞的凋亡诱导活性并研究其机制。方法 MTT法检测肺癌细胞系A549在顺铂和川楝素处理下的细胞活力。Western blot试验检测顺铂和川楝素对A549细胞ATF2磷酸化水平，Bcl-xl蛋白表达水平、细胞色素c释放水平、caspase-9和caspase-3活化水平的影响。流式细胞术检测A549细胞在顺铂和川楝素联合处理下的细胞凋亡率。结果 MTT试验结果显示，川楝素辅助治疗能明显提降低顺铂对A549的IC₅₀。Western blot试验结果显示川楝素处理能显著抑制A549细胞ATF2的表达和磷酸化。MTT试验结果显示，转染ATF2表达质粒显著抑制川楝素对顺铂的协同抗肺癌活性。Western blot和流式细胞试验结果显示，川楝素能显著抑制A549细胞中顺铂诱导的Bcl-xl表达水平的上调，进而促进A549细胞中顺铂诱导的细胞色素c的释放、caspase-9和caspase-3活化及A549细胞的凋亡水平。结论 川楝素通过抑制ATF2蛋白的磷酸化增强顺铂对肺癌细胞的凋亡诱导活性。

Toosendaninl Enhances Cisplatin-induced Apoptosis in Lung Cancer Through Downregulating the Expression of ATF2

OBJECTIVE To investigate the effect and mechanisms of toosendaninl treatment on enhancing cisplatin-induced apoptosis in lung cancer cells. METHODS MTT assay was performed to measure the cell viability of A549 cells treated with toosendaninl and cisplatin. Western blot analysis was performed to detect the phosphorylation of ATF2, expression of Bcl-xl, release of cytochrome C and activation of caspase-9 and caspase-3 in A549 cells treated with toosendaninl and cisplatin. Flow cytometry analysis was performed to measure the cell apoptosis of A549 cells treated with toosendaninl and cisplatin. RESULTS Results of MTT assays showed that toosendaninl treatment decreased the IC₅₀ of cisplatin to A549. Results of Western blot analysis showed that toosendaninl treatment inhibited the expression and phosphorylation of ATF2 in A549 cells treated with cisplatin. In addition, transfection with ATF2 plasmid abolished the synergistic effect of toosendaninl on cisplatin-induced cell death. Results of Western blot and flow cytometry analysis toosendaninl treatment inhibited the cisplatin-induced upregulation of Bcl-xl, and thus promoting release of cytochrome C, activation of caspase-9 and caspase-3 and cell apoptosis. CONCLUSION toosendaninl enhances cisplatin-induced apoptosis in lung cancer through promoting the phosphorylation of ATF2.