沉默FOXC2对TGF-β1诱导的MCF-7细胞上皮-间质转化的逆转作用

 目的： 探讨沉默叉头框C2(FOXC2)表达对转化生长因子β1（TGF-β1）诱导的人乳腺癌MCF-7细胞上皮-间质转化(EMT)的逆转作用和对乳腺癌侵袭性的影响。方法： 将体外培养的MCF-7细胞用5 μg/L TGF-β1处理，相差显微镜观察细胞形态学变化；免疫荧光检测EMT相关标志物表达。慢病毒介导的FOXC2-siRNA载体转染至TGF-β1诱导成功的MCF-7细胞，以RT- PCR和Western blotting方法检测FOXC2及EMT相关标志物上皮性钙黏蛋白(E-cad)、紧密连接蛋白 1(CLDN1)、纤维连接蛋白 1(FN1) mRNA及蛋白表达；Transwell小室模型检测沉默FOXC2表达对TGF-β1诱导的MCF-7细胞侵袭性的影响。结果： TGF-β1可诱导MCF-7细胞向间质样细胞表型转换，并上调间质样标志物FN1表达和下调上皮样标志物E-cad及CLDN1表达；而沉默FOXC2表达可逆转已间质化的MCF-7细胞恢复至上皮表型，并降低其侵袭性。结论： TGF-β1可诱导人乳腺癌MCF-7细胞发生EMT并增加其侵袭性，且TGF-β1这种诱导作用能被FOXC2-siRNA所逆转，并降低细胞的侵袭能力。

The reverse effect of FOXC2 silencing on epithelial-mesenchymal transition induced by TGF-β1 in MCF-7 cell

ABSTRACT] AIM: To study the reverse effect of FOXC2 silencing on epithelial-mesenchymal transition induced by TGF-β1 in MCF-7 cell. Furtherly research for its role on invasion of breast cancer. METHODs: Cultured MCF-7 cells were treated with 0.005mg/L concentration of TGF-β1 for 6 day. The cell morphological changes were observed under phase contrast microscopy. EMT relative markers protein changes were assessed by immunofluorescence staining assay. MCF-7 cells induced by TGF-β1 were transfected with FOXC2-siRNA vector mediated by recombinant lentivirus. In addition, The expression of FOXC2 and EMT relative marker protein(E-cad、CLDN1、FN1) were also measured by RT- PCR and Western blotting respectively. The invasion of MCF-7 cell was detected by transwell invasion. RESULTs: The data showed that TGF-β1 could induced MCF-7 cell morphological alteration from epithelial to mesenchymal and up-regulated the expression of mesenchymal makers FN1 and down-regulated the expression of epithelial makers E-cad and CLDN1. FOXC2 silencing could reversed mesenchymal MCF-7 cells restored to epithelial phenotype and reduced tumor invasion. CONCLUSION: Epithelial-mesenchymal transition model induced by TGF-β1 in breast cancer MCF-7 cell was successful established, Which increased the invasion of MCF-7 cells. The effect of TGF-1 was reversed by FOXC2-siRNA and reduced its invasion.