目的 探讨FoxM1是否调控DNA修复基因Rad51参与顺铂(CDP)对骨肉瘤耐药细胞化疗抑制作用.方法 采用逐步增加剂量间歇作用的方法诱导骨肉瘤耐药细胞系并分别命名为MG-63/R和HOS-MNNG/R.qRT-PCR、Western blot法检测耐药细胞与亲本细胞FoxM1和Rad51的mRNA及蛋白表达;耐药细胞中4μmol/L Thiostrepton处理后qRT-PCR、Western blot法检测FoxM1和Rad51的mRNA及蛋白表达.细胞计数法检测单独或联合运用4μmol/L Thiostrepton和2-μg/mL CDP对骨肉瘤耐药细胞增殖率的影响.结果 建立在2 μg/mL CDP浓度中稳定生长的耐药细胞系MG-63/R和HOS-MNNG/R,耐药指数分别为30.52和37.87(均重度耐药).FoxM1和Rad51的mRNA及蛋白水平在耐药细胞中表达较亲本细胞明显增高;在耐药细胞中联合运用4 μmol/L Thiostrepton和2μg/mL CDP组较单独应用4μmol/L Thiostrepton组或2μg/mL CDP组细胞增殖率明显降低;耐药细胞4 μmol/L Thiostrepton处理后FoxMl及Rad51的mRNA和蛋白表达均明显降低.结论 FoxM1及Rad51高表达可能参与骨肉瘤细胞对CDP耐药,FoxM1抑制剂Thiostrepton可能通过下调Rad51增强CDP对骨肉瘤耐药细胞的抑制作用.%Purpose To investigate whether FoxM1 participate in inhibitory effect of cisplatin (CDP) in resistant osteosarcoma cell lines by down-regulation of Rad51.Methods The resistant osteosarcoma cell lines were induced by gradually increasing dose intermittent action,and were named MG-63/R and HOS-MNNG/R respectively.The mRNA and protein level of FoxMl and Rad51 were detected by qRT-PCR and Western blot analysis in resistant cells and parental cells.The mRNA and protein level of FoxM1 and Rad51 were detected by qRT-PCR and Western blot analysis in resistant cells after treatment of 4 μmol/L Thiostrepton.The effect of single or combined treated of 4 tμmol/L Thiostrepton or 2 tμg/mL CDP on the rate of cell proliferation in resistant cells was examed by cell counting.Results Resistant osteosarcoma cell lines MG-63/R and HOSMNNG/R were established and stablely growthed in the concentration of 2 μg/mL CDP,and the resistance index was 30.52 and 37.87 respectively (severe CDP resistance).The mRNA and protein level of FoxM1 and Rad51 were significantly increaced in resistant cells compared with parental cells.The proliferation rate of resistant cells in conbination of 4 μmol/L Thiostrepton and 2 μg/mL CDP treated group was significantly lower than these two drugs single treated group.The level of mRNA and protein of FoxM1 and Rad51 were significantly decreased after 4 μmol/L Thiostrepton treatment in CDP resistant cells.Conclusion The results suggest that FoxM1 and Rad51 may participate in the resistant osteosarcoma cells to CDP.FoxM1 inhibitor Thiostrepton may strengthen the inhibitory effect of CDP in the resistant cells by down-regulation of Rad51.
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