The Research Of MTH1 Expression And Its Influence On Epithelial-mesenchymal Transition In Breast Cancer

Background:Previous studies have confirmed that MTH1 can repair the damage caused by reactive oxygen species, and it has a high level in many tumor cells. But whether MTH1 exists in breast cancer cells and affects its biological behavior, there is no specific study.Purposes:In this study, we first investigate the expression of MTH1 in breast cancer cell lines with different degrees of malignancy. Then explore the effects of MTH1 on the biological behavior of breast cancer cells including migration, invasion and proliferation. Finally, analysis of the effect of MTH1 on epithelial mesenchymal transition in breast cancer cells.Methods:In this study, using Western Blot, Real-time PCR and other methods, to explore the expression of MTH1 in breast cancer cell lines with different degrees of malignancy, screening out the MTH1 high expression and low expression of the cell lines. Subsequently constructed MTH1 over expression plasmid, transfected MTH1 low expression cell line, combined with siRNA transfected MTH1 high expression cell line, analysis the effects of MTH1 on the biological behaviors of breast cancer cell proliferation, migration and invasion by MTT colorimetric assay, plate clone formation assay, Edu cell proliferation assay and Transwell migration assay. Finally,by Western Blot and immunofluorescence test to discuss the effects of MTH1 on breast cancer cells of epithelial mesenchymal transition effect.Results:Through the study, it was found that the expression level of MTH1 in breast cancer cells was significantly higher than that in normal breast epithelial cells, and the expression level increased with the malignant degree of breast cancer cell lines. By transfection of MTH1 expression plasmid into MCF-7(MTH1 low expression cell line) to improve the expression level of MTH1 and by transfection of si RNA into MDA-MB-231(MTH1 low expression cell line) to inhibit the expression of MTH1,from the two aspects of the square that MTH1 expression can promote breast cancer cell migration and proliferation ability, so as to improve breast cancer biology malignancy. In addition, MTH1 can also up regulate the mesenchymal marker protein N-cadherin and Vimentin, down regulate the epithelial marker protein E-cadherin and cytokeratin, and promote the epithelial mesenchymal transition of breast cancer cells.Conclusion:MTH1 is highly expressed in breast cancer cells, and the level of expression is positively correlated with the malignant degree of tumor cells. In addition, MTH1 can promote the breast cancer cells migration, proliferation, and the occurrence of epithelial mesenchymal transition. So MTH1 is a kind of substance that can promote the occurrence of breast cancer and improve the biological malignant degree.