靶向下调FOXM1基因表达对乳腺癌MDA-MB-231细胞增殖的影响

目的：探讨靶向抑制FOXM1对乳腺癌细胞增殖能力的影响，为乳腺癌的个性化靶向治疗提供理论依据。方法：利用重组真核转录载体pSilencer1．0-U6-FOXMI—shRNA，脂质体法转染乳腺癌细胞株MDA-MB-231，下调其FOXM1基因表达。采用四甲基偶氮唑盐（MTT）比色法、平板克隆形成实验观察细胞增值曲线以及克隆形成能力；采用实时定量·聚合酶链反应（Real—timeqPCR）、蛋白免疫印迹法（Westemblot）分别检测FOXMl基因在mRNA、蛋白水平的表达变化。结果：重组载体pSileneerl．0-U6-FOXMl-shRNA转染MDA-MB-231细胞后，与对照组相比，增殖速率明显下降（P〈0．05），平板克隆形成显著减少（P〈0．05），重组载体转染后显著抑制MDA—MB-231细胞中FOXM1基因在mRNA、蛋白水平的表达。结论：沉默FOXMI基因对乳腺癌细胞株MDA—MB-231生长具有抑制作用，为阐明乳腺癌发病机制提供了新的切入点，也为临床抑制肿瘤生长提供了新的作用靶点。

Effects of Silencing FOXM1 on Cell Proliferation of Human Breast Cancer Cell Line MDA-MB-231

Objective： This experiment is designed to figure out the effect of breast cancer cells proliferation after target silencing ofFOXM1, thus providing a mineral strategy for individualized and target breast cancer therapy. Methods： The recombinant vectors with shRNA targeting FOXM1 （pSilencer1.0-U6-FOXMI-shRNA） were transfected into MDA-MB-231 cells with the help of lippofectamine 2000 to down regulate the expression of FOXM1. MTT assay and Colony Forming Assay were used to evaluate the proliferation and colony forming efficacy of MDA-MB-231 cells. Meantime, Real-Time quantitative Polymerase Chain Reaction （RT-qPCR） and Western blot assay were performed to monitor the expression of mRNA and protein level of FoxM 1. Results： After transfection of the pSilencerl. 0-U6-FOXMI-shRNA target FOXM1, cell proliferation was enormously decreased compared to control groups （P〈0.05）. FOXM1 expression in the transfected MDA-MB-231 cells was significantly depressed both at mRNA and protein level. Conclusion： The pSilencerl.0-U6-FOXMl-shRNA target FOXM1 could efficiently inhibit FOXM1 gene expression in breast cancer cell line MDA-MB-231. Stable silence of FOXM1 gene by shRNA could negatively regulate cell proliferation in human breast cancer MDA-MB-231 cells. This experiment could provide a new insight into the mechanism of breast cancer and suggest a promising target of suppression cancer growth.