The Effection Of Caveolin-1 On ERα Mediated Metastasis And Adhesion Pathway In Human Mammary Cells

Breast cancer is the most commonly diagnosed cancer type in women and ranks the second in female cancer deaths. Caveolin, a 21-24 kD membrane protein, is an essential structural molecule of Caveolae. Caveolin-1, one of Caveolin family members, participates in many important life activities in the cells. Recent studies found that Caveolin-1 had a close relationship with the transformation and carcinogenesis of mammary epithelial cells.In this study, we used human mammary cell MCF10A (Cav-1 high expression), high metastasis breast cancer cell MDA-MB-231 (Cav-1 high expression), low metastasis breast cancer cell MCF-7 (Cav-1 low expression), then we established MCF10A^CE and MDA-MB-231^siRNA-Cav-1 cell lines which Caveolin-1 decreased, and MCF-7^poRF-hCav-1 cell line which Cav-1 increased. We detected the capacity of adhesion, migration and metastasis in these cells by adhesion assay, migration assay and transwell assay. Then, MCF10A^CE was treated with 17β-estradial (E2) and ICI182,780. We examined adhesion and metastasis related molecules by Microarray, immunocytochemistry, immunoblotting, RT-PCR and gelatin zymography assay.Results: 1) We detected the adhesion, migration and invasion ability of MCF10A^CE cell, we found that Cav-1 gene silencing significantly enhanced cell adhesion, migration and invasion. DNA microarray analysis showed that 125 genes vary in adhesion, metastasis and estrogen receptor signaling pathway, including 5 adhesion related genes were decreased, and 6 metastasis related genes were increased. RT-PCR, Western Blot, immunocytochemistry and gelatin zymograghy results showed that adhesion and metastasis related genes were abnormal activation in MCF10A^CE cell; 2) We used E2, ICI182,780, and both of them to treat MCF10A^CE cells, we found that the group of combination with E2 and ICI182,780 can significantly reduce the expression of metastasis-related genes, so maybe the function of Cav-1 is via estrogen receptor signaling pathway; 3) We established Cav-1 low expression cell line MDA-MB-231^siRNA-Cav-1 and Cav-1 high expression cell line MCF-7^poRF-hCav-1, through wound healing assay, we found that the migration ability of these two cell lines were lower than maternal cells, and the expression of proliferation and metastasis related proteins were also reduced.Caveolin-1 efficiently inhibited metastasis through activation of the membrane-initiated signaling pathways in human mammary cells, and this is mediated by MT1-MMP/MMP-2 pathway. Caveolin-1 is of potential values as a novel therapeutic agent for human breast cancer.