线粒体融合素基因-2对乳腺癌细胞增殖的影响及其机制

The effect of mitofusin-2 gene on cell proliferation and the chemotherapy sensitivity of human breast carcinoma cell line

目的观察外源性线粒体融合素基因-2（Mfn2）对乳腺癌细胞（MCF-7）增殖的影响，探讨其抑制乳腺癌细胞产生增殖的机制。方法将含有Mfn2cDNA的质粒在阳离子聚合物的介导下在体外转染MCF-7，蛋白印记法（Western blot）检测绿色荧光蛋白（GFP）、p21^wafl、CDK2蛋白的表达，细胞计数测定Mfn2对MCF-7细胞增殖的影响，DNA直方图分析法测定Mfn2对MCF-7周期分布的影响，用Cyclins／DNA双参数流式细胞术对CyclinA进行标记，Cellquest软件分析。结果转染Mfn2基因的MCF-7细胞可以稳定高表达GFP蛋白；细胞计数测定表明转染Mfn2cDNA后，MCF-7细胞增殖明显受抑，DNA直方图分析法测定显示细胞停滞于S期；转染质粒组S期细胞占42．70％，转染空质粒组和空白对照组分别为17．15％、19．58％（P〈0．05）；用Cyclins／DNA双参数流式细胞术检测转染质粒组CyclinA较对照两组明显升高；Westernblot显示转染质粒组p21高表达，磷酸化CDK2低表达。结论转染Mfn2基因可以明显抑制MCF-7细胞的增殖，并使细胞停滞于S期。

Objective To study the role and mechanism of mitofusin-2 gene in cell proliferation of human breast carcinoma cell line MCF-7 after in vitro transfer. Methods pEGFP Mfn2 was transferred by sofast in vitro. The expression of GFP was detected by Western blot, and the cell proliferation of MCF-7 by cell counting. Cell cycle of MCF-7 was observed by DNA analytical method,and the expression of Cyclin A examined by Cyclins/DNA flow cytometry, and the expression of p21^walf, CDK2 by Western blot. Re- suits The stable expression of GFP protein in MCF-7cells was confirmed by Western blot. Mfn2 could also induce cell cycle arrest （S） by DNA analytical method. The percentage of S phase cells was 42.70 in thansfer group,whereas in control groups it was 17.15 and 19.58 respectively （P 〈0.05）. Mfn2 could induce the expression of Cyclin A protein obviously ,and the expression of p21 was high and phosphorylated CDK2 was low. Conclusion Mfn2 can strongly inhibit cell proliferation in MCF-7 cell line, and result in cell arrest in S phase.