Activin A Regulates The Biological Behavior Of MCF-7 And MDA-MB-231 Cells Through ERK Signaling

According to the World Oncology Annual Report 2020,breast cancer has become the highest incidence cancer,which replaced lung cancer.Breast cancer is the highest mortality cancer among women in the world.Previous studies have shown that activin A plays a dual regulatory role in the process of tumorgenesis,development and metastasis.But the signal transduction mechanism of activin A regulating the migration and proliferation of breast cancer cells has not been clarified.Follistain(FST)can bind to activin A with high affinity and participate in the regulation of a variety of cell biological behaviors together with activin A.Therefore,MCF-7 and MDA-MB-231 cells were selected to analyze the effect of activin A on the biological behavior of breast cancer and further determine whether activin A regulates the biological behavior of MCF-7 and MDA-MB-231 cells through ERK signaling pathway using small molecule inhibitors.1.METHODS(1)The relationship between activin βA and FST m RNA expression and the prognosis of breast cancer was analyzed by bioinformatics;(2)The expression levels of autocrine activin A and FST were detected by ELISA;(3)Cell apoptosis was examined by flow cytometry with Annexin V-PI staining;(4)Cell migration was assayed by microfluidic chip technology;(5)Signal pathway protein expression was determined by Western blotting.2.RESULT(1)There were differences in the expression of ActβA and FST m RNA in different types of cancer,and the expression level of ActβA was associated with the prognosis of breast cancer;(2)ActβA and FST m RNA were high expressed in MDA-MB-231 cells,but low expressed in MCF-7 cells.ELISA results showed that MDA-MB-231 cells secreted high expression level of activin A,while MCF-7 cells secreted low expression level of activin A.The expression level of FST were lower than the ELAST minimum values in the supernatants of MCF-7 and MDA-MB-231;(3)Both exogenous activin A and FST inhibited proliferation of MCF-7 cells and promoted apoptosis of MCF-7 cells;activin A promoted proliferation of MDA-MB-231 cells and inhibited apoptosis of MDA-MB-231 cells,while FST inhibited proliferation of MDA-MB-231 cells and promoted apoptosis of MDA-MB-231 cells.Activin A and FST both inhibited activity of MCF-7.Activin A promoted activity of MDA-MB-231 cells while FST inhibited activity of MDA-MB-231;(4)Exogenous activin A and FST both inhibited migration of MCF-7 cells,which is related to inhibition of α-SMA expression and promotion of E-cadherin expression.Activin A induced migration of MDA-MB-231 cells,which was related to promotion of Vimentin and Ezrin expression.FST inhibited migration of MDA-MB-231 cells,which was related to inhibition of α-SMA expression;(5)Activin A had no effect on the expression of Smad3 in MCF-7 and MDA-MB-231 cells,but down-regulated p-ERK1/2 protein level in MCF-7 cells and up-regulated p-ERK1/2 protein level in MDA-MB-231 cells.The effect of activin A on the biological behavior of MCF-7 and MDA-MB-231 cells was inhibited by the application of FR180204 which is a small molecule inhibitor of ERK1/2.3.CONCLUSIONIn conclusion,MCF-7 and MDA-MB-231 cells have different expression levels of activin A,and MCF-7 and MDA-MB-231 do not secrete FST protein.Activin A and FST have different effects on the biological behavior of MCF-7 and MDA-MB-231 cells,which may be related to the expression levels of activin A secreted by the two types of breast cancer cell lines.The results show that activin A regulates the biological behavior of MCF-7 and MDA-MB-231 cells through the ERK signaling rather than classical Smad signaling pathway.The above studies not only further reveal the mechanism of activin A regulating the biological behavior of breast cancer cells,but also provide a new research basis for accurate treatment targets for breast cancer.