si RNA干扰β-catenin基因对多发性骨髓瘤细胞耐药性的影响

Effect of siRNA-Interfering β-Catenin Expression on MDR of Human Multiple Myeloma Cell Line

目的:探讨小片段RNA(siRNA)干扰β-catenin基因表达对多发性骨髓瘤细胞系RPMI-8226耐药性的影响。方法:体外培养多发性骨髓瘤细胞系RPMI-8226,通过药物浓度梯度递增法建立马法兰耐药细胞模型;β-catenin-siRNA瞬时转染耐药细胞株,采用CCK-8法检测转染前后细胞对马法兰的敏感性变化,应用qRTPCR、Western-blot法分别检测β-catenin基因和蛋白表达水平的变化,流式细胞术检测细胞凋亡率。结果:耐药骨髓瘤细胞经β-catenin-siRNA转染后对马法兰的IC50值由(5.29±0.19)μmol/L降至(1.88±0.64)μmol/L。Western-blot法检测显示,瞬时转染β-catenin-siRNA后β-catenin蛋白表达水平明显较转染前降低;转染后马法兰诱导细胞凋亡率由(35±0.5)%升高到(54±0.4)%,提示β-catenin基因可能与细胞耐药性相关,干扰β-catenin基因表达可提高耐药骨髓瘤细胞对于马法兰的敏感性。结论:β-catenin-siRNA干扰可抑制Wnt/β-catenin信号途径中β-catenin基因表达,抑制细胞增殖,增强马法兰对耐药骨髓瘤细胞株RPMI-8226毒性,增加细胞凋亡率。

Objective:To investigate the effecr of siRNA-interfering β-catenin expression on drug-resistance of multiple myeloma cells.Methods:The multiple myeloma cell line RPMI-8226 was cultured in vitro.The maphalanresistant cell model was established by concentration gradient ascending of durg,then the drug-resistant cell line was instantaneously transfected with β-catenin siRNA,the sensitivity of RPMI 8226 cells to maphalan was detected by CCK-8 meltod before and after the transfection with siRNA;the mRNA and protein expression of β-catenin was detected by qRT-PCR and Western blot respectively,the apoptosis of cells was detected by flow cytometry.Results:IC50 of maphalan decreased from(5.29±0.19)μmol/L to(1.88±0.64)μmol/L,suggesting that the deplation of β-eatenin restored the sensitivity of drug-resistant cell line RPMI-8226 to malphalan.The Western blot showed that after the instaintaneous transfection with β-catenin siRNA,the β-catenin protein expression level obviously decreased,compared with level before transfection.After transfection,the maplalan-inducing apoptosis rate of cells increased from(35±0.5)%to(54±0.4)%,suggesting that the β-catinin gene may correlated with drug-resistance of cells.Interfering the expression of β-catenin gene could enhance the sensitivity of drug-resistant RPMI-8226 cells to maphalan.Conclusion:Theβ-catenin siRNA interfereuce can inhisit the β-catenin gene expression in Wnt/β-catenin signaling pathway,suppress the cell proliferation,enhence the toxicity of maphalan on drug-resistant RPMI-8226 cells,thus result in increase of cell apoptosis.