黄芪多糖联合顺铂对人肺癌A549细胞增殖抑制作用及其机制研究

摘要

Objective To observe the inhibitory effects of astragalus polysaccharides and cisplatin on the cell prolifera-tion,cycle,apoptosis induction of human lung cancer A549 cells,and initially discuss its action mechanism. Methods The ef-fects on cell proliferation of astragalus polysaccharides ,cisplatin and their combinations was detected by MTT assay. It analyzed the impact of cell cycle and apoptosis rate by flow cytometry. The A549 human lung cancer cells Bax ,Bcl-2 and Caspase-3 gene expression levels by reverse transcription polymerase chain reaction (RT-PCR) and Western blotting. Results Astragalus polysac-charide,cisplatin and two-drug combination on inhibition of proliferation of human lung cancer A549 cells had a time-concentra-tion-dependent proliferation. Compared with the negative control group ,the cell cycle blockage in G1 phase after astragalus polysaccharide action while the cell cycle blockage in S phase after cisplatin action and the application of two-drug combination appeared cell cycle blockage by flow cytometry both in G1 and S phases(P<0.01). The expression of Bax,Caspase-3 mRNA and pro-tein were upgraded in the expression of the two-drug combination group and lowered in Bcl-2 mRNA protein compared to the nega-tive control and monotherapy group. The difference had statistical significance (P<0.05). Conclusion The astragalus polysaccharide combined with cisplatin may strengthen human lung cancer A549 cells to enhance the pro-apoptosis,whose mechanism is associ-ated with upgrading the expression of Bax ,Caspase-3 and lowering the expression of Bcl-2mRNA.%目的：观察黄芪多糖与顺铂对人肺癌A549细胞增殖、细胞周期、诱导凋亡的影响，并对其作用机制进行初步探讨。方法采用四甲基偶氮唑盐法检测黄芪多糖、顺铂及两药联合对细胞增殖的影响；用流式细胞仪分析对细胞周期及凋亡率的影响；用反转录聚合酶链反应（RT-PCR）和Western blotting法检测对人肺癌A549细胞B细胞淋巴瘤-白血病2（Bcl-2）、Bcl相关X蛋白（Bax）和半胱氨酸天冬氨酸蛋白酶3（Caspase-3）基因表达水平的影响。结果黄芪多糖、顺铂及两药联合对人肺癌A549细胞的增殖抑制作用呈时间-浓度依赖关系；与阴性对照组比较，黄芪多糖作用后可出现G1期细胞阻滞，顺铂作用后出现S期细胞阻滞，两药联合出现G1、S期细胞阻滞，差异均有统计学意义（P<0.01）。两药联合较阴性对照组及单用黄芪多糖、顺铂明显上调Bax、Caspase-3 mRNA及蛋白的表达，下调Bcl-2 mRNA及蛋白的表达，差异均有统计学意义（P<0.01）。结论黄芪多糖可协同顺铂增强对人肺癌A549细胞的促凋亡作用，其作用机制与上调Bax、Caspase-3的表达、下调Bcl-2的表达有关。