盐霉素抑制人肺腺癌耐顺铂细胞株A549/DDP增殖及诱导凋亡的机制

目的: 探讨盐霉素对人肺腺癌耐药细胞株A549/DDP增殖的抑制作用及其可能机制。方法: 采用MTT法检测盐霉素对A549/DDP细胞生长的抑制作用;流式细胞术检测盐霉素对A549/DDP细胞凋亡及线粒体膜电位(ΔΨ_m)的影响;比色法检测caspase-3、8和9活性;Western blotting分析细胞色素C、Bcl-2、Bax、β-catenin和磷酸化低密度脂蛋白受体相关蛋白6(p-LRP6)蛋白水平。结果: 盐霉素对A549/DDP细胞生长具有剂量依赖性抑制作用。0.2 μmol/L盐霉素作用于A549/DDP细胞,ΔΨ_m显著下降,而细胞内活性氧和Ca²⁺浓度在短期显著升高,胞浆细胞色素C蛋白水平、caspase-3、8和9酶活性均显著增加,与对照组比较差异均有统计学意义(P<0.01);Bcl- 2 的表达下调,Bax 的表达明显增加,Bcl-2/Bax 比值显著降低。48 h时增殖抑制率为(34.61±1.97)%,细胞凋亡率为(18.74±2.08)%。盐霉素也减少A549/DDP细胞内β-catenin和p-LRP6蛋白水平。结论: 盐霉素通过抑制Wnt信号通路抑制A549/DDP细胞增殖,通过Bcl-2/Bax途径和线粒体凋亡途径诱导人肺腺癌耐药细胞株A549/DDP凋亡。

Salinomycin inhibited proliferation and induced apoptosis of cisplatin-resistant human lung adenocarcinoma cell line A549/DDP

AIM: To investigate the effect of salinomycin on the proliferation and apoptosis of cisplatin-resistant human lung adenocarcinoma cell line A549/DDP.METHODS: The inhibitory effect of salinomycin on the growth of A549/DDP cells was tested by MTT method in vitro.The apoptosis and mitochondrial membrane potential(ΔΨm) of A549/DDP cells were assayed by flow cytometry.The activity of caspase-3,8 and 9 was determined by the method of colorimetry.The levels of cytochrome C,Bcl-2,Bax,β-catenin,and phosphorylated low-density lipoprotein receptor-related protein 6(p-LRP6) were measured by Western blotting.RESULTS: Salinomycin inhibited the growth of A549/DDP cells in a dose-dependent manner.Salinomycin at concentration of 0.2 μmol/L decreased ΔΨm level,and increased reactive oxygen species(ROS),cytochrome C and cytosolic Ca2+ release in the cells.Salinomycin also increased the acti-vity of caspase-3,8,and 9 in the cells,reduced the ratio of Bcl-2/Bax,and decreased the levels of β-catenin and p-LRP6.CONCLUSION: Salinomycin depresses the cell growth by inhibiting Wnt signaling,and induces the apoptosis of cisplatin-resistant human lung adenocarcinoma cell line A549/DDP via mitochondria-dependent and Bcl-2/Bax pathways.