雷公藤红素逆转乳腺癌细胞对多柔比星的抵抗性及机制研究

目的: 探讨天然药物活性成份雷公藤红素是否能逆转乳腺癌细胞对多柔比星的耐药性并研究其机制。方法: 将多柔比星耐药MDA-MB-231细胞(MDA-MB-231/R细胞)按对照组,雷公藤红素组,多柔比星组,雷公藤红素+多柔比星组及雷公藤红素+多柔比星+Bim siRNA组进行分组后,MTT法检测MDA-MB-231/R的细胞活力,流式细胞术检测MDA-MB-231/R细胞的凋亡,免疫共沉淀实验检测MDA-MB-231/R细胞Bim蛋白与Bak及Bax蛋白的相互作用,western blot实验检测MDA-MB-231/R细胞色素c的释放和caspase-3的活化。结果: MDA-MB-231/R细胞对多柔比星的IC50显著高于常规MDA-MB-231细胞(P<0.05)。雷公藤红素处理可诱导MDA-MB-231/R细胞Bim蛋白的上调及其与Bak、Bax蛋白的相互作用(与对照组或多柔比星处理组比较,P<0.05)。雷公藤红素+多柔比星组对MDA-MB-231/R细胞活力的抑制率和凋亡诱导率显著高于多柔比星组(P<0.05)和雷公藤红素+多柔比星+Bim siRNA组(P<0.05)。雷公藤红素+多柔比星组对MDA-MB-231/R细胞色素c的释放和caspase-3的活化显著高于多柔比星组(P<0.05)和雷公藤红素+多柔比星+Bim siRNA组(P<0.05)。结论: 雷公藤红素通过上调Bim蛋白的表达提高多柔比星耐药乳腺癌细胞对多柔比星的敏感性。

Celastrol increased the sensitivity of doxorubicin-resistant breast cancer cells to doxorubicin by upregulating the expression of Bim.

AIM: To investigate the role and mechanisms of celastrol in reversing the doxorubicin-resistance in the breast cancer cells. Methods: The doxorubicin-resistant MDA-MB-231 cells (MDA-MB-231/R cells) were grouped as control group, celastrol group, doxorubicin group, and doxorubicin+celastrol group. Then, the MTT assays were performed to measure the cell viability; Flow cytometry analysis was performed to detect the cell apoptosis; Co-immunoprecipitation analysis was performed to evaluate the interaction of Bim with Bak and Bax; Western blot analysis was performed to evaluate the release of cytochrome c and the activation of caspase-3. Results: The IC50 of doxorubicin to MDA-MB-231/R cells was significantly higher than the routine MDA-MB-231 cells (P<0.05). Treatment with celastrol significantly induced the expression of Bim and the subsequent interaction of Bim with Bak and Bax (compared with the control group or the doxorubicin group, P<0.05). Cell viability inhibitory rate and apoptotic rate of MDA-MB-231/R cells in celastrol+doxorubicin group was significantly higher than that in the doxorubicin group (P<0.05) and the celastrol+doxorubicin+Bim siRNA group (P<0.05). The release of cytochrome c and activation of caspase-3 in the celastrol+doxorubicin group was more remarkable than that in the doxorubicin group (P<0.05) and the celastrol+doxorubicin+Bim siRNA group (P<0.05) in MDA-MB-231/R. Conclusion: Celastrol increased the sensitivity of doxorubicin-resistant breast cancer cells to doxorubicin by upregulating the expression of Bim.