辛伐他汀对SHI-1细胞株多药耐药基因和蛋白的影响

Effects of Simvastatin on Expression of Multidrug Resistance Gene and Protein of SHI-1 Cells

目的:研究辛伐他汀(simvastatin,SIM)及无血清培养液(serum free medium,SFM)对急性髓系白血病(AML)细胞株SHI-1多药耐药基因(MDR1)及蛋白表达的影响。方法:应用台盼蓝拒染法检测SIM处理及SFM培养后SHI-1细胞的增殖水平及细胞活力变化;定量PCR法检测SFM培养液及SIM作用对MDR1基因转录本表达水平的影响;流式细胞术检测SFM培养液及不同浓度SIM作用后SHI-1细胞多药耐药蛋白(p-gp)表达水平的变化;ELISA法检测SFM培养及SIM作用后细胞内胆固醇水平的变化,并进一步检测SIM作用后SHI-1对化疗药物敏感性的变化。结果:SHI-1细胞在SFM中生长速度明显低于正常血清培养组,呈时间依赖性;在SFM培养条件下,同时加入SIM,结果显示对细胞增殖的抑制作用显著增强。SFM培养能够下调SHI-1细胞MDR1基因及p-gp蛋白的表达水平;SIM对MDR1基因及p-gp蛋白表达水平也有抑制作用,呈浓度依赖性;在SFM培养条件下加SIM,细胞MDR1基因及p-gp水平显著下调。在SFM培养条件下细胞内胆固醇水平较有血清培养组上升,当加入SIM作用后,细胞内胆固醇水平则明显下降。经SIM预先处理的SHI-1细胞对柔红霉素更为敏感,细胞死亡率明显高于未处理组。结论:SIM及SFM培养能够显著抑制具有多药耐药表型的SHI-1细胞增殖,并能够下调SHI-1细胞p-gp蛋白及MDR1基因表达水平;SIM能够增加多药耐药细胞SHI-1对化疗药物的敏感性。

Objective：To investigate the effects of simvastatin（SIM） and serum free medium（SFM） on the expression of multidrug resistance gene（MDRl） and protein of SHI-1 cells.Methods：Trypan blue exclusion assay was used to detect the proliferation level and viability of SHI-1 cells after treatment with SIM and culture in SFM;The multi-drug resistant protein p-gp was measured by flow cytometry after culture in SFM for 1 to 3 days and treatment with various concentration of simvastatin.The effect of SFM culture and SIM treatment on the expression of MDRl trascript was detected by qPCR;ELISA was used to measure the change of cellular cholesterol after culture in SIM and SFM.Chemosensitivity assay was performed after treatment with SIM for SHI-1 cells.Results：Compared with control group,the growth of SHI-L cells cultured in SFM decreased in a time-dependent manner.The growth-inhibitory effect was markedly increased when SHI-1 cells were treated with SIM and SFM.The mRNA level of MDRl gene decreased after SIM treatment or/and culture in SFM.P-gp protein was downregulated in SHI-L cells cultured in SFM or/and treated with SIM.The cellular cholesterol level increased when the cells were cultured in SFM.Total cellular cholesterol level decreased in SHI-L cells treated with SIM and cultured in SFM.Chemosensitivity assays found that pre-treatment with SIM could increase the cytotoxicity of DNR to SHI-1 cells.Conclusion：Culture with SIM and SFM can downregulate the expression of MDRl gene and p-gp protein in SHI-1 cells.SIM also can enhance the chemotherapeutic sensitivity of SHI-L cells.