The Effect Of HSP90 On Proliferation Of Human Breast Cancer Cells And Its Molecular Mechanisms

Objectives:To investigate the effect of HSP90 on proliferation of human breast cancer cells by a specific inhibitor for HSP90, geldanamycin (GA), and to analyze its molecular mechanisms.Methods: The human breast cancer cell line MDA-MB-435s was used as a model. Proliferation of MDA-MB-435s cells was measured with MTT assay. Cell cycle was analyzed by flow cytometry. Telomerase activation was detected with TRAP-ELISA. The expression of phosphorylated stat3 protein and mutant p53 protein in cells were detected by Western blot. The expression of HSP27, HSP70 and HSP90 were detected by RT-PCR and Western blot.Results: Geldanamycin inhibited the proliferation of MDA-MB-435s cells on a time-dose-depending manner. After treatment of GA, MDA-MB-435s cell cycle were arrested at G2 /M phase, telomerase activation was decreased. The expression level of phosphorylated stat3 protein and mutant p53 protein in MDA-MB-435s cells were reduced obviously with 55% and 48% respectively after 48 hours treatment with...