Mdm2 siRNA诱导LoVo细胞凋亡的研究

Apoptotic induction by mdm2 siRNA on human colorectal carcinoma cell lines LoVo

目的研究mdm2 siRNA(small interfering RNA)在诱导结直肠癌LoVo细胞凋亡的作用。方法将mdm2siRNA转染入LoVo中,通过RT-PCR和Western blot技术检测mdm2 mRNA及MDM2蛋白表达水平,应用生长曲线、流式细胞技术、TUNEL技术及MTT来检测mdm2 siRNA诱导LoVo细胞凋亡的效应。结果转染mdm2 siRNA后的Lo-Vo细胞中mdm2基因mRNA水平及MDM2蛋白表达水平明显减低;细胞的增殖受到明显的抑制;mdm2 siRNA在凋亡早期及晚期中均可发挥明显诱导作用;MTT观察可见药物顺铂对对照组细胞的半数抑制浓度是联合应用mdm2siRNA后的5.33倍。结论mdm2 siRNA能够有效的抑制mdm2基因的表达进而诱导结直肠癌LoVo细胞的凋亡,并且增加了LoVo细胞对细胞毒药物顺铂的敏感性。

Objective To investigate the effect of mdm2 Small interfering RNA（siRNA） on apoptosis in human colorectal carcinoma cell lines LoVo cells. Methods LoVo cells were transfected with mdm2 siRNA. RTPCR and Western blot analysis of mdm2 mRNA and protein expression in LoVo cells. Growth curve, Flowcytometry, TUNEL assay and MTr colorimetry were used for determination of apoptosis in LoVo cells. Results Transfection of LoVo ceils with mdm2 siRNA significantly inhibited MDM2 expression at both mRNA and protein level in LoVo cells; treatment of LoVo cells with mdm2 siRNA resulted in growth inhibition; this significantly increased apoptotic cell rate. mdm2 siRNA had an effect on induction of either early or late stage apoptosis. We also found that when combined with DDP,mdm2 siRNA significantly inhibited tumor growth with reductions in tumor cells compared with that seen with mdm2 siRNA. Conclusion Mdm2 siRNA effectively inhibits mdm2 gene expression in LoVo cells and leads to induction of apoptosis in LoVo cells. And it also enhances the sensitivity to DDP. The use of mdm2 siRNA technique may provide a novel therapeutic approach to treat tumors.