AIM:To explore the therapeutic effect of adriamycin combined with rapamycin on endometrial cancer cells. METHODS; Two endometrial carcinoma cell lines with different PTEN gene states were chosen; HEC - 1A (wild type) and Ishikawa (mutant type). Before adriamycin administration, the cells were pretreated with low concentration of rapamycin for 24 h. The cell viability and 50% inhibitory concentration (IC50 ) of adriamycin at 24 h were determined by MTT assay. Multiple drug effect/combination index ( CI) was used to evaluate the interaction between adriamycin and rapamycin. Apoptotic rate was measured by flow cytometry. The effects of the drugs on phosphorylation of PBK/Akt and apoptosis protein caspase - 3 were detected by Western blotting. RESULTS: Both adriamycin and rapamycin showed obvious growth inhibitory effects on the 2 endometrial cancer cell lines in a time - and dose - dependent manner. After pretreated with rapamycin, IC50 of adriamycin decreased sharply. In Ishikawa cells, it decreased from (21.3 ±3.8) μmol/L to (11.9 ±1.2) μmol/L,P<0. 05. In HEC - 1A cells, it decreased from (14. 3 ±2. 8) μmol/L to (8. 2 ±0.9) μmol/L,P<0.05. Combination index value of the 2 drugs was more than 1.15 in the 2 endometrial cancer cell lines, indicating synergistic effects. The combination therapy of adriamycin with rapamycin increased apoptotic rates in the 2 cell lines, and induced the down - regulation of phosphorylated Akt and over - expression of caspase - 3 as compared with single drug treatment (P<0.05). CONCLUSION: Adriamycin combined with rapamycin significantly enhances the chemo-sensitivity of endometrial cancer cells and reduces drug resistance, which will become a new trend for treating endometrial cancer.%目的:探讨mTOR抑制剂雷帕霉素联合阿霉素对子宫内膜癌细胞株的影响及其机制.方法:选用2株不同PTEN状态的子宫内膜癌细胞株:HEC-1A(PTEN野生型)和Ishikawa(PTEN突变型),分别给予低浓度雷帕霉素预处理24 h,再使用阿霉素,MTT法检测联合用药前后阿霉素24 h IC50及细胞生存率的变化,计算两药的联合指数;流式细胞术检测细胞凋亡率,Western blotting观察PI3K/Akt通路的蛋白磷酸化和凋亡蛋白caspase-3的变化.结果:(1)雷帕霉素或阿霉素单药使用时均明显抑制2株子宫内膜癌细胞的生长.抑制率与时间、剂量呈正相关.使用10 nmol/L雷帕霉素预处理24 h后,阿霉素作用Ishikawa细胞的IC50由(21.3±3.8)μmol/L降到(11.9±1.2) μmol/L(P<0.05);而HEC-1A细胞的IC50由(14.3±2.8)μmol/L降到(8.2±0.9)μmol/L(P<0.05);2株细胞中阿霉素与雷帕霉素的联合指数均大于1.15,提示在2种细胞株中两药均有协同作用;(2)联合用药后,凋亡率较单药使用组明显升高(P<0.05);同时,p-Akt蛋白表达下降,而活化的caspase-3表达上调.结论:雷帕霉素能增加子宫内膜癌细胞对阿霉素的敏感性,从而降低肿瘤细胞对药物的耐药性,具有良好的抗肿瘤前景.
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