CTEN在乳腺癌细胞上皮间质转化中的作用与机制研究

目的:探讨CTEN在乳腺癌细胞上皮间质转化中的作用及其分子机制。方法:采用定量PCR及Western blotting检测人乳腺癌MCF-7和MDA-MB-231细胞中CTEN的表达水平；然后用Lipofectamine 2000将CTEN高表达质粒pcmv-CTEN转染至乳腺癌MCF-7细胞，为高表达组，将对照质粒pcmv转染至MCF-7细胞，为对照组，用定量PCR检测两组细胞中CTEN、Snail和EMT标记分子mRNA水平的变化，用Western blotting检测CTEN、Snail和EMT标记分子蛋白水平的变化；应用Lipofectamine 2000将CTEN干扰质粒siCTEN转染至MDA-MB-231细胞，为干扰组，将对照质粒siNC转染至MDA-MB-231细胞，为对照组，分别用定量PCR和Western blotting检测两组细胞中CTEN、Snail和EMT标记分子mRNA及蛋白水平的变化；应用Lipofectamine 2000将Snail干扰质粒siSnail转染至MCF-7细胞，为干扰组，将对照质粒siNC转染至MCF-7细胞，为对照组，分别用定量PCR和Western blotting检测两组细胞中Snail mRNA及蛋白水平的表达情况，然后再将CTEN高表达质粒pcmv-CTEN转染入两组细胞，定量PCR检测CTEN和EMT标记分子mRNA水平的变化，Western blotting检测CTEN和EMT标记分子蛋白水平的变化。结果:CTEN在MDA-MB-231中的表达量高于MCF-7细胞；与对照组相比，高表达CTEN组的MCF-7细胞形态呈纺锥形，Snail表达升高，上皮标记分子E-cadherin表达下降，间质标记分子N-cadherin及Vimentin表达升高，促进EMT的发生；与对照组相比，敲低CTEN组的MDA-MB-231细胞形态呈鹅卵石形，Snail表达下降，上皮标记分子E-cadherin表达上升，间质标记分子N-cadherin及Vimentin表达下降，促进MET的发生；在MCF-7细胞中干扰Snail后再过表达CTEN，其促进EMT的作用明显减弱。结论:CTEN能够诱导乳腺癌细胞发生上皮间质转化，且其可能通过转录因子Snail发挥作用。

CTEN induces epithelial-to-mesenchymal transition in breast cancer cells and its molecular mechanism

Objective:To explore the effects and mechanism of CTEN on epithelial-to-mesenchymal transition in breast cancer cells.Methods:The expression of CTEN in MCF-7 and MDA-MB-231 was detected by qRT-PCR and Western blotting.The MCF-7 cells were divided into high expression group and control group，then transfected with pcmv-CTEN and pcmv with Lipofectamine 2000.CTEN，Snail and EMT biomarkers were detected by qRT-PCT and Western blotting.The MDA-MB-231 cells were divided into low expression group and control group，then transfected with siCTEN and siNC with Lipofectamine 2000.CTEN，Snail and EMT biomarkers were detected by qRT-PCT and Western blotting.Snail silenced and control cell lines were constructed in MCF-7 cells by the transfection of siSnail and siNC with Lipofectamine 2000.Snail expression was detected by qRT-PCT and Western blotting，then pcmv-CTEN and pcmv were transfected with Lipofectamine 2000 in MCF-7 cells in which Snail was silenced，then CTEN and EMT biomarkers were detected by qRT-PCT and Western blotting.Results:The expression of CTEN in MDA-MB-231 was higher than in MCF-7.Compared with control group，the expression of Snail and mesenchymal markers in CTEN high expression group were enhanced，and the epithelial marker was descended，which induced the EMT process.Meanwhile，the MCF-7 cells with high expression of CTEN showed a conical shape.Compared with control group，the expression of Snail and mesenchymal markers in siCTEN group were decreased，and the epithelial marker was increased，which induced the MET process.Meanwhile，the MDA-MB-231 cells with low expression of CTEN showed cobblestone morphology.The enhanced EMT induced by CTEN could be reversed by interfering Snail.Conclusion:CTEN induce epithelial-to-mesenchymal transition in breast cancer cells，which may act through activating Snail.