线粒体分裂在甲状腺鳞癌SW579细胞增殖、凋亡以及侵袭中的作用

Effects of mitochondrial fission in proliferation, apoptosis and invasion of thyroid squamous carcinoma cell line SW579

目的研究线粒体动力学蛋白Mfn2和Drp1在甲状腺鳞癌SW579细胞中的表达和线粒体分裂抑制剂-1(Mdivi-1)对SW579细胞增殖、凋亡及侵袭能力的影响。方法采用RT-PCR检测Mfn2和Drp1 m RNA,Westernblot检测Mfn2和Drp1蛋白在Nthy-ori 3-1和SW579两种细胞中的表达;然后将SW579分为对照组(DMSO,0.1%)和Mdivi-1低、中、高剂量组(浓度分别为15、30、45μmol/L),培养16 h,采用MTT法检测细胞增殖能力的变化,用荧光分光光度计检测线粒体膜电位的变化,用RT-PCR检测细胞色素C(Cyt C)和Caspase-3 m RNA的变化,Westernblot检测Cyt C和Caspase-3蛋白的变化,用Transwell小室侵袭实验检测侵袭能力的变化。结果与Nthy-ori 3-1细胞系相比,SW579细胞系中Mfn2 m RNA和蛋白表达明显降低,Drp1 m RNA和蛋白表达明显升高(P<0.01);与对照组相比,Mdivi-1各组SW579细胞存活率和线粒体膜电位均明显降低,Cyt C和Caspase-3的m RNA及蛋白表达均明显增加,侵袭能力明显减弱(均P<0.01),并且呈药物浓度依赖性。结论甲状腺鳞癌SW579细胞中存在线粒体动力学异常,Mdivi-1可以抑制此细胞的增殖和侵袭,并能诱导其凋亡。

Objective To detect the expression of mitochondrial dynamics proteins（Mfn2 and Drp1） in thyroid squa-mous carcinoma cell line SW579 and the effects of Mitochondrial division inhibitor, Mdivi-1, on proliferation, apoptosis andinvasion of SW579. Methods In SW579 and Nthy-ori 3-1 cell lines, the expression levels of Mfn2 and Drp1 were deter-mined by western blot while the transcription level of Mfn2 and Drp1 mRNA were measured by RT- PCR. Then, SW579 cells were divided into control group（DMSO, 0.1%） and Mdivi-1 low, medium and high dose groups（Mdivi-1 of 15,30 and45 μmol/L were incubated with cells for 16 hours respectively）. Then the ability of cell proliferation was detected using MTTassay, the mitochondrial membrane potential was determined by fluorescence spectrophotometer, the expression levels of cy-tochrome C and Caspase-3 were quantified by Western blot and the transcription level of the Cyt C and Caspase-3 mRNAwere determined by RT-PCR. The ability of invasion in each group was measured with Transwell assays. Results Com-pared with Nthy-ori 3-1, the mRNA transcription and protein expression levels of the Mfn2 was remarkably decreased,while the mRNA transcription and protein expression of the Drp1 was significantly increased in SW579 cells（P〈0.01）.Compared with control group, the cell survival rates and mitochondrial membrane potential of SW579 were decreased dramat-ically（P〈0.01）. The mRNA transcription and protein expression of the cytochrome C and Caspase-3 were increased dra-matically（P〈0.01） and the capability of invasion was markedly decreased in all the Mdivi-1 groups in a dosage dependentmanner compared with those in control groups（P〈0.01）. Conclusion Abnormal mitochondrial dynamics may be involvedin thyroid squamous cell carcinoma SW579 cells; Mdivi-1 can inhibit the cell proliferation and invasion as well as induceapoptosis.