Effect Of Epinephrine On Proliferation And Migration Of Human Breast Cancer MDA-MB-231 Cells And Its Related Mechanism

ObjectiveTo evaluate the effects of epinephrine on the proliferation and migration of human breast cancer MDA-MB-231 cells and to explore its related mechanisms.Methods1.The expression ofβ2 adrenergic receptor on the surface of human breast cancer MDA-MB-231 cells and human normal breast epithelial MCF-10A cells were detected by Western blot.2.Different concentrations of Epinephrine（0.001,0.005,0.01,0.05,0.1,0.5,1,5,10,20,40,60,80,100,500,1000μmol/L）and non-toxic doses of beta 2adrenergic receptor blockers Propranolol were used to treat human breast cancer MDA-MB-231 cells.After 12 h,24 h,36 h,the proliferation of MDA-MB-231 cells was detected by MTS assay.Based on the above indexes,Epinephrine and Propranolol with appropriate concentration were selected for subsequent experiments.3.Human breast cancer MDA-MB-231 cells were treated with Epinephrine and Epinephrine+Propranolol respectively,while the control group was set without any treatment factors,and the following related tests were performed:（1）MTS assay was used to detect cell proliferation.（2）Cell migration was detected by cell scratch assay.（3）Flow cytometry was used to detect the expression of molecular marker CD44+/CD24-/Low on the surface of breast cancer stem cells.（4）The expressions of ERK signal transduction pathway related proteins（ERK1/2,P-ERK1/2）and their downstream cell proliferation-related protein（C-MYC）and cell migration-related proteins（MMP-2,MMP-9）were detected by Western Blot.Results1.Compared with normal human breast epithelial MCF-10A cells,the surface of human breast cancer MDA-MB-231 cells showed higher expression ofβ2-adrenoceptor（P<0.05）.2.When the concentration of epinephrine was less than 100μmol/L,it could significantly promote the proliferation of MDA-MB-231 cells（P<0.05）,but did not show a dose-dependent effect.When the concentration of epinephrine was higher than 100μmol/L,it could dose-dependent inhibit the proliferation of human breast cancer MDA-MB-231 cells due to the cytotoxic effect of epinephrine.At the concentration of 0.5μmol/L,propranolol had no significant effect on the proliferation of human breast cancer MDA-MB-231 cells.In order to better evaluate the effect of epinephrine on the proliferation and migration of human breast cancer MDA-MB-231 cells,we selected epinephrine with a concentration of no more than 100μmol/L for subsequent experiments,and epinephrine with a concentration of 0.1μmol/L and propronaphthalene with a concentration of 0.5μmol/L for the evaluation of relevant mechanisms.3.After treatment with epinephrine,the proliferation and migration of MDA-MB-231 cells were significantly increased（P<0.05）,and the expression of CD44⁺/CD24^-/low on the surface of breast cancer stem cells was significantly increased（P<0.05）.However,the effects of epinephrine were significantly decreased after treatment with propranolol（P<0.05）.4.The expressions of p-ERK1/2,c-MYC,MMP-2 and MMP-9 in human breast cancer MDA-MB-231 cells treated with epinephrine were significantly increased（P<0.05）.However,the expressions of p-ERK1/2,c-MYC,MMP-2 and MMP-9 in breast cancer MDA-MB-231 cells treated with epinephrine+propranolol were significantly decreased compared with those treated with epinephrine alone（P<0.05）.ConclusionsEpinephrine can promote the proliferation and migration of human breast cancer MDA-MB-231 cells through regulating the ERK1/2 signaling pathway mediated byβ2 adrenaline receptor on the cell surface.