Impact of let-7g on Proliferation and Lactation of Mouse Mammary Epithelial Cells

摘要

let-7g,a member of the let-7 family,regulates gene expression at the post-transcriptional level.The study explored a series of biological effects of mouse mammary epithelial cells that let-7g was produced.The differential expression of let-7g was detected by qRT-PCR in different developmental stages of the mouse mammary gland.let-7g expression and impact of let-7g on mouse mammary epithelial cells were analyzed by CASY-technology,qRT-PCR,Western blotting and HPLC inhibited let-7g expression of mouse mammary epithelial cells through gene silencing.The results showed that qRT-PCR identified let-7g as being down-regulated in mouse mammary epithelial cells after it was inhibited.Mouse mammary epithelial cells with low expression of let-7g displayed higher expression of TGFβRⅠprotein than those with high expression of let-7g,suggesting that low let-7g expression contributed to TGFβRⅠover-expression.Finally,the expression of let-7g was down-regulated,which significantly enhanced the proliferation of mouse mammary epithelial cells,and increased expression of β-Casein.The data indicated that let-7g could negatively regulate the expression of target Tgfbr1 by complementary combination in mouse mammary epithelial cells,and then regulate the cell proliferation and expression of β-Casein by suppressing the TGFβRⅠexpression.