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 Micro RNA-21 Expression in K562/IM Cells

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mi R-21和Bcl-2蛋白表达水平的改变;并采用micro RNA转染技术,观察mi R-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(25μmol·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,mi R-21和Bcl-2蛋白水平显著降低;mi R-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mi R-21表达水平、抑制靶基因Bcl-2蛋白表达有关。

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 micro RNA-21 was measured by fluorescence quantitative polymerase chain reaction. Bcl-2 protein level was measured by Western blot. After transfected with micro RNA-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 micro RNA-21 and Bcl-2 were significantly decreased after curcumin treatment. Meanwhile, after transfected with micro RNA-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 micro RNA-21 and Bcl-2 expression.