Over-expression of fructose-1, 6-bisphosphatase 1 gene inhibits the migration of breast cancer tamoxifen-resistant cells and induces apoptosis / 肿瘤

ABSTRACT

Objective: To investigate the effects of over-expressing fructose-1, 6-bisphosphatase 1 (FBP 1) gene on migration and apoptosis of tamoxifen-resistant MCF-7 human breast cancer cells. Methods: The levels of FBP1 mRNA and protein in human breast cancer tamoxifen-sensitive MCF-7 cells and tamoxifen-resistant MCF-7R cells were measured by real-time fluorescent quantitative PCR and Western blotting, respectively. Then, the FBP1 over-expression plasmids were transfected into MCF-7R cells by lipofectin, and the expression levels of FBP1 mRNA and protein were detected by real-time fluorescent quantitative PCR and Western blotting in order to verify the over-expression of FBP 1 gene. After that, the morphology of MCF-7R cells with FBP1 over-expression was observed under an inverted optical microscope, the abilities of cell migration and apoptosis were measured by cell wound healing experiment and FCM assay, respectively. Furthermore, the expressions of apoptosis-associated proteins Bcl-2 and Bax as well as the epithelial-mesenchymal transition (EMT) markers E-cadherin and vimentin were detected by Western blotting. Results: The mRNA and protein levels of FBP1 in human breast cancer tamoxifen-resistant MCF-7R cells were lower than those in tamoxifen-sensitive MCF-7 cells (both P< 0.01). After the transfection of FBP1 over-expression plasmids, the mRNA and protein expressions of FBP1 were significantly up-regulated in MCF-7R cells (both P< 0.01), MCF-7R cells had a change from mesenchymal-like morphology to epithelial-like morphology, the apoptotic index of MCF-7R cells was increased (P < 0.01), but the ability of cell migration was decreased (P < 0.01). Moreover, the protein expressions of Bcl-2 and vimentin were obviously down-regulated (both P<0.01), while the protein expressions of Bax and E-cadherin were significantly up-regulated (both P<0.01). Conclusion: The over-expression of FBP 1 gene can significantly inhibit cell migration and EMT in human breast cancer tamoxifen-resistant MCF-7R cells, and promote apoptosis through decreasing Bcl-2 expression and increasing Bax expression.