沉默YAP基因提高伊马替尼耐药的人髓性白血病细胞K562药物敏感性的研究

YAP gene silencing to improve the drug sensitivity of imatinib resistant myeloid leukemia cells K562

目的:探究沉默YAP基因后,提高伊马替尼耐药的K562细胞(K562/IMA)对于伊马替尼敏感性的作用及相关机制,为伊马替尼耐药的人髓性白血病治疗提供参考。方法:采用小干扰RNA技术(siRNA)转染YAP的siRNA-YAP沉默K562/IMA的YAP基因。设置对照组(Control)、siRNA阴性对照组(siRNA-NC)和YAP siRNA组(siRNA-YAP)。采用RT-qPCR和Western blot法鉴定沉默后各组细胞YAP蛋白和mRNA的表达水平。CCK-8法检测各组细胞对于伊马替尼的敏感性,并计算半数抑制浓度IC50。流式细胞术检测各组细胞的凋亡率。Western blot法检测YAP、Bcl-2、Bax、cleaved-caspase-3、caspase-3、细胞色素C(Cyto-C)的表达水平,Transwell小室检测细胞转移侵袭能力。结果:YAP基因沉默后,siRNAYAP组细胞中YAP的蛋白和mRNA表达水平显著低于Control组和siRNA-NC组,沉默效果较好。siRNA-YAP的IC50值显著低于Control组和siRNA-NC组,具有统计学意义(P <0. 05),而流式细胞术结果显示,siRNA-YAP组细胞在相同药物剂量下,凋亡率显著高于Control组和siRNA-NC组,具有统计学意义(P <0. 05)。YAP沉默的K562/IMA细胞迁移侵袭能力显著下降。伊马替尼干预后,siRNA-YAP细胞中Bcl-2/Bax的水平下调,cleaved-caspase-3、caspase-3和Cyto-C的水平上调,相比Control组和siRNA-NC组,具有统计学意义(P <0. 05)。结论:沉默伊马替尼耐药的K562/IMA细胞中YAP基因,可以恢复肿瘤细胞对于伊马替尼的敏感性,可以促进线粒体凋亡途径的激活,导致耐药肿瘤细胞的凋亡。

AIM： To explore the effect and mechanism of enhanced imatinib resistant K562 cells （K563/IMA） on imatinib sensitivity after YAP gene silencing, and to support the treatment of imatinib resistant myeloid leukemia. METHODS：Transfection of YAP gene silencing with siRNA-YAP was conducted by small interference RNA technique （siRNA） in K562/IMA. The control group （con- trol）, the siRNA negative control group （siRNANC ） and the YAP siRNA group （siRNA-YAP） were established. The expression level of YAP protein and mRNA in each cell after silencing was identified by RT-QPCR and Western blot. The sensitivity of each cell to imatinib was detected by CCK-8, and the median inhibitory concentration of IC50 was cal- culated. Flow cytometry was used to detect the apoptosis rate of each group. The expression level of YAP, Bcl-2, Bax, cleaved-caspase3, caspase-3 and Cyto-C were detected by Western blot. The metastasis and invasion were detected by Transwell compartment. RESULTS ： After the YAP gene silenced, the expression level of YAP protein and mRNA in the siRNA-YAP was significantly lower than that in the control and the siRNA-NC. The IC50 value of siR- NA-YAP was significantly lower than that of control and siRNA-NC, which was statistically significant （P 〈 0.05 ）. The results of flow cytometry showedthat the apoptotic rate of siRNA-YAP was significantly higher than that of control and siRNA-NC at the same dosage, which was statistically significance （P 〈0. 05 ）. The migration and invasiveness of K562/IMA cells in YAP silenced were decreased significantly. After imatinib intervene, the level of Bcl-2/Bax in siRNA-YAP cells was down-regulated, and the levels of cleaved-caspase3, caspase-3 and Cyto-C were up-regulated. Compared with control and siRNA-NC, it was statistically significant （P 〈 0. 05）. CONCLUSION：To silence the YAP gene in imatinib resistant K562/IMA cells can restore the sensitivity of tumor cells to imatinib, and promote the activation of mitochondrial apoptotic pathway, resulting in the apoptosis of drug-resistant tumor ceils.