MS-275阻断STAT3信号通路诱导U251细胞凋亡

Indution of apoptosis of U251 cells by blocking STAT3 signaling pathways with MS-275

目的 探讨组蛋白去乙酰化酶抑制剂MS-275对脑胶质瘤细胞株U251细胞增殖的影响及促凋亡机制.方法 以不同药物浓度梯度和U251细胞分别共培养24、48、72 h后,应用CCK-8法检测肿瘤细胞增殖,瑞氏-姬姆萨染色法观察细胞形态变化,PI单染法检测细胞周期,Annexin V-FITC/PI法经流式检测细胞凋亡率,免疫印迹检测STAT3蛋白和PARP蛋白表达.结果 MS-275能显著抑制U251细胞的增殖,药物浓度40 nmol/ml,培养72 h,抑制率为（79.0±1.7）%;经药物作用后,细胞呈现凋亡形态,胞质和胞核浓缩或碎裂;G0/G1期细胞由（66.320±0.456）%降至（38.288±1.242）%（P＜0.01）,G2/M期细胞由（19.940±0.580）%升高至（35.650±0.507）%,而后降至（22.343±1.224）%（P＜0.01）,亚G0凋亡峰由（0.230±0.035）%增高至（18.393±1.449）%（P＜0.01）;总凋亡率由（2.133±0.416）%增高至（29.000±2.307）%（P＜0.01）;免疫印迹检测提示磷酸化STAT3表达水平降低,PARP被剪切.结论 MS-275对胶质瘤细胞的增殖抑制作用具有浓度和时间依赖性,它通过阻断STAT3磷酸化,诱导激活Caspase-3凋亡途径.

Objective To investigate the effect of MS-275 on the proliferation of brain glioma cells. Methods U251 cells were respectively cultured for 24, 48, 72 h, with different concentrations of MS-275. CCK-8 assay was used to assess the proliferation of U251 cells. The morphological changes of U251 cells were observed by Wright-Giemsa staining. The cell cycle was analyzed by PI dyeing. The apoptosis rate was assayed by flow cytometry using annexin V-FITC/PI. The protein expression of STAT3 and PARP was detected by Western blotting. Results MS-275 could significantly inhibited proliferation of U251 cells. After treatment with MS-275, apoptosis of U251 cells was seen; The ratio of G0/G1 was decreased from （ 66.320 ± 0.456 ） % to （ 38. 288 ± 1. 242 ） % （ P 〈 0. 01 ）, the percentage of G2/M cells was increased from （ 19. 940 ± 0. 580 ） % to （ 35.650 ± 0. 507 ） %, then decreased to （ 22. 343 ± 1. 224 ） %（P〈0.01）, and ratio of sub-G0 was increased from （0.230 ±0.035）% to （18.393 ±1.449）% （P〈0. 01 ）; Total apoptosis rate was increased from （ 2. 133 ± 0.416 ） % to （ 29. 000 ± 2. 307 ） % （ P 〈 0. 01 ）;The expression level of phosphorylated STAT3 was significantly downregulated, and the cleavage of PARP was detected by Western blotting. Conclusion MS-275 inhibites proliferation of brain glioma cells in a time- and dose-dependent manner, which is achieved by inducing apoptosis.