The Mechanism Of EphB2 Receptor In The Migration Process Of Hormone-dependent Breast Cancer Cell MCF-7 Induced By Cortisol

Part 1 Effect and mechanism of cortisol on proliferation and migration of hormone-related breast cancer MCF-7 cells.Objective To investigate the proliferation and migration effect of cortisol on hormone-related breast cancer MCF-7 cells.Methods MCF-7 cells,originated from a hormone-related breast cancer woman,were treated with different concentration of cortisol.The effect of cortisol on cell proliferation was determined by MTS assay and the rate of cell survival was calculated The effect of cortisol on cell migration was examined by wound-healing assay.The protein expression of phospho mTOR(pmTOR)which is involved in cell proliferation and MMP-9,MMP-2 which are related to cell migration,were detected by Imnunoblot analysis.Results Cortisol at concentration of 10nM significantly increased cell proliferation(*p<0.05)and cell migration(*p<0.05)compared with vehicle group.Furthermore,cortisol at concentration of 10nM obviously increased the protein expression involved in cell proliferation(pmTOR,*p<0.05)and cell migration(MMP-9,*p<0.05;MMP-2,**p<0.01).Conclusion Cortisol at concentration of 10nM effectively induced cell proliferation and cell migration by activating mTOR pathway and upregulating MMP-9 and MMP-2 protein expression.Part 2 EphB2 receptor involved in regulation of cortisol-induced migration on hormone-related breast cancer MCF-7 cells.Objective To investigate the effect and the mechanism of EphB2 on hormone-related breast cancer cells(MCF-7)migration induced by cortisol.Methods MCF-7 cells were treated with different concentration of cortisol for 24h.Fluorescent indicator 5-(and-6)-carboxy-2',7'-dichlorodihydrofluorescein diacetate(carboxy-H2DCFDA)was used to detect the cellular reactive oxygen species(ROS)level.The protein expression of EphB2 was detected by Immunoblot analysis.After treated with DOX(doxycycline),an EphB2 receptor antagonist,wound healing test was undertaken to test cell migration.The protein expression of MMP-9,MMP-2 which are related to cell migration were detected by Immunoblot analysis.Results Cortisol at coneentration of 10nM significantly increased levels of ROS(**p<0.01)and the protein expression of EphB2 compared with vehicle groups,and both the effect could be reversed when RU486 treated##p<0.01).Furthermore,when treated with DOX,the protein of EphB2 expression decreased(**p<0.01),cell migration of MCF-7(**p<0.01)as well as the protein expression involved in cell migration(MMP-9,*p<0.05;MMP-2,**p<0.01)decreased.Conclusion Cortisol at concentration of 10nM effectively induced cell migration which was related to EphB2 upregulating the protein expression of MMP-2 and MMP-9.