替莫唑胺对人胶质瘤细胞系U251细胞的增殖影响

摘要

目的 探讨替莫唑胺(TMZ)对人胶质瘤细胞系U251细胞的杀伤作用及其作用机理.方法 将人胶质瘤细胞系U251细胞分成空白对照组、TMZ组和常用化疗药物组,TMZ组下设10、25、50、100、200、400 μmol/L组,常用化疗药物组(ADM、MTX、VCR、DDP)各药物浓度均为其IC50值.各组分别于作用后24、48、72 h观察细胞形态学改变,用MTT比色法检测细胞活力,流式细胞仪检测细胞周期和凋亡率.结果 ①TMZ组各浓度对U251细胞的抑制率分别为4.23%、7.43%、31.63%、64.53%、82.18%、86.15%,呈良好的时间-剂量效应关系,其IC50为81 μmol,初始抑制浓度为50 μmol;②ADM、MTX、VCR、DDP对U251细胞的抑制率分别为39.27%、44.59%、54.56%、55.28%,VCR、DDP两药的抑制作用明显优于ADM、MTX(P均＜0.01),与TMZ的杀伤作用相当(P＞0.05);③流式细胞仪检测显示,U251细胞经TMZ作用后出现G2/M期阻滞,但促凋亡作用不强.结论 TMZ对胶质瘤细胞有明显的杀伤作用,并呈时间和剂量依赖性;TMZ可使胶质瘤细胞阻滞于G2/M期,但其促凋亡作用不强;替莫唑胺对U251细胞的杀伤作用优于其他4种常用化疗药物.%Objective To investigate the proliferation and the cell cycle effect of temozolomide(TMZ) on human neuroblastoma cell line U251 cells. Methods U251 cells were treated with 6 different concentrations of TMZ (10, 25, 50, 100, 200, 400 μmol/L) 24, 48, 72 h and with 5 antineoplastic agents(CTX, ADM, MTX, VCR, DDP)72 h respectively. The morphological changes of the cells were observed under light microscopes. Cell viability was accessed by using colorimetric MTT assay. U251 cells were treated with 50 and 100 μmol/L TMZ 72 h. Cell cycle progression and apoptosis ratio were measured by using flow cytometry. Results Inhibition ratio of 6 different concentrations of TMZ were 4.23%,7.43%,31.63%,64.53%,82.18% and 86.15% respectively. The IC50 of TMZ was 81 μmol/L. There were significant difference between the control group and the groups over 50 μmol/L (P＜0.01). Inhibition ratio of different concentrations TMZ increased gradually as time went by. Inhibition ratio of ADM, MTX, VCR and DDP were 26.22%, 39.27%, 44.59%, 54.56% and 55.28% respectively. There were significant difference between the TMZ group and the ADM, the MTX group respectively (P＜0.01). There were no significant difference between the TMZ group and the VCR, the DDP group respectively (P＞0.05). The flow cytometry showed that U251 cells responded to TMZ by undergoing G2/M arrest and very few cells underwent apoptosis. Conclusions TMZ inhibits the viability of malignant glioma cells in a time- and dose-dependent manner, and induces G2/M arrest but not apoptosis in vitro. The function of TMZ killing U251 cells in vitro is better than that of the other four drugs