替莫唑胺耐药细胞系 SHG-44／TR 生物学特征及其耐药机制

摘要

Objective To investigate the biological characteristics and resistance mechanism of human glioma cell line SHG-44/TR which is resistant to temozolomide ( TMZ) .Methods We induced the human glioma SHG-44 to be re-sistant to TMZ by dose escalation in vitro, and then established the drug-resistant cell line SHG-44/TR.The colony forma-tion assay and MTT colorimetric assay was used to measure the proliferation, resistance and resistance index of SHG-44/TR cells;Western blotting was used to detect the expression changes of resistance protein O6-methylguanine-DNA methyl trans-ferase (MGMT) and human mismatch repair protein 2 (hMSH2);and flow cytometry was used to detect the SHG-44/TR cell cycle.Results After eight months, we successfully established TMZ-resistant glioma cells SHG-44/TR.Significant difference was found in the TMZ-resistance between SHG-44 and SHG-44/TR (P<0.05).SHG-44/TR had no cell cycle arrest phenomenon.The expression of MGMT protein did not change in SHG-44/TR cells as compared with that of parent cells, but the expression of hMSH2 was significantly decreased (P<0.05).Conclusions The hMSH2 expression of TMZ-resistant glioma cells SHG-44/TR is decreased, and the mechanism may be DNA mismatch repair missing.%目的：探讨对替莫唑胺耐药的人胶质瘤细胞系SHG-44／TR的生物学特征及耐药机制。方法通过体外分阶段剂量递增诱导法使人脑胶质瘤细胞系SHG-44对替莫唑胺产生耐药性，建立耐药细胞系SHG-44／TR。采用细胞集落形成试验和噻唑蓝比色法检测SHG-44／TR增殖情况、耐药性及耐药指数；采用Western -blotting法检测耐药蛋白O6-甲基鸟嘌呤-DNA甲基转移酶（MGMT）及人类错配修复蛋白2（hMSH2）表达变化；流式细胞仪检测SHG-44／TR细胞周期变化。结果历时8个月成功建立了对替莫唑胺耐药的人胶质瘤细胞 SHG-44／TR。与SHG-44比较，SHG-44／TR对替莫唑胺的耐受程度差异有统计学意义（P＜0．05）；SHG-44／TR没有细胞周期阻滞现象；SHG-44／TR较亲本细胞MGMT蛋白表达无变化，hMSH2表达差异有统计学意义（P＜0．05）。结论耐替莫唑胺胶质瘤细胞系SHG-44／TR hMSH2表达降低，其耐药机制可能为DNA错配修复缺失。