姜黄素通过调节miR-21干预伊马替尼耐药K562/IM细胞的化疗敏感性

Curcumin Enhance the Sensitivity of Imatinib by Decreasing MicroRNA-21 Expression in K562/IM Cells

关键词:  姜黄素  miR-21  伊马替尼  K562细胞  耐药  化疗敏感性

Key words:  curcumin  microRNA-21  imatinib  K562 cells  drug resistance  chemotherapy sensitivity

摘要:

目的 研究姜黄素对伊马替尼耐药的K562细胞(K562/IM)多药耐药性的逆转作用，并探讨其机制。方法 采用MTT法分析姜黄素对于K562/IM细胞的增殖抑制作用，并选取非毒性浓度姜黄素联合伊马替尼作用于K562/IM，分析其增殖抑制效应；流式细胞术检测其协同诱导细胞凋亡的作用；实时荧光定量PCR和Western blot法检测姜黄素对于miR-21和Bcl-2蛋白表达水平的改变；并采用microRNA转染技术，观察miR-21对细胞增殖抑制和Bcl-2 蛋白表达的影响。结果 非毒性浓度(25 μmol·L^-1)姜黄素能显著增强K562/IM细胞对伊马替尼的敏感性，并能增强伊马替尼诱导细胞凋亡的作用，使K562/IM细胞平均凋亡率由6.3%提高到23.6%(P<0.05)；姜黄素作用后，miR-21和Bcl-2蛋白水平显著降低；miR-21抑制剂转染K562/IM细胞后，可显著降低Bcl-2表达，提高K562/IM细胞对伊马替尼的敏感性。结论 姜黄素可增强K562/IM细胞对伊马替尼的敏感性，并诱导其凋亡，其作用机制可能与下调miR-21表达水平、抑制靶基因Bcl-2 蛋白表达有关。

Abstract:

OBJECTIVE To investigate the reversal effect of curcumin on drug resistance in imatinib-resistant K562 (K562/IM) cells and explore the possible mechanism. METHODS The K562/IM cells were treated with curcumin at non-toxicity concentration alone or combined with imatinib, respectively. Cell viability was measured by MTT assays. The apoptosis of cells were detected by Annexin V/PI method. The expression of microRNA-21 was measured by fluorescence quantitative polymerase chain reaction. Bcl-2 protein level was measured by Western blot. After transfected with microRNA-21 mimic and inhibitor, the sensitivity of imatinib and Bcl-2 protein level on K562/IM cell were analyzed. RESULTS Curcumin at non-toxicity concentration (25 μmol·L^-1) could significantly enhance the sensitivity of K562/IM cells to imatinib and promoted the imatinib-induced cell apoptosis. The apoptosis rate of K562/IM cells were increased from 6.3% to 23.6% after the combined use of curcumin and imatinib (P<0.05). Levels of microRNA-21 and Bcl-2 were significantly decreased after curcumin treatment. Meanwhile, after transfected with microRNA-21 inhibitor, a significant down-regulation of Bcl-2 protein and a significant up-regulation of sensitivity to imatinib were noted on K562/IM cells. CONCLUSION Curcumin could significantly enhance the sensitivity of K562/IM cells to imatinib and induce the cell apoptosis, these effects may be attribute to the down-regulation effect of curcumin on microRNA-21 and Bcl-2 expression.