Abstract

To investigate the effects of the sex determining region Y-box 2 gene silencing on biological characteristics and the mitogen-activated protein kinase kinase kinase kinase 4 signal pathway of breast cancer cells. Firstly, the expression of sex determining region Y-box 2 in breast cancer was detected by the immunohistochemical method and the relationship with clinicopathological features was analyzed. Then the sex determining region Y-box 2 silencing breast cancer cell line Michigan Cancer Foundation-7 was prepared, and the messenger ribonucleic acid and protein expression levels of sex determining region Y-box 2, c-Jun N-terminal kinase, p53 and tumor necrosis factor-alpha in the mitogen-activated protein kinase kinase kinase kinase 4 pathway were detected by quantitative polymerase chain reaction and western blotting. Cell proliferation, migration, invasion and apoptosis were detected by the Cell Counting Kit-8, scratch test, transwell test, and flow cytometry. After si-sex determining region Y-box 2 transfection, the expression of sex determining region Y-box 2, c-Jun N-terminal kinase, p53 and tumor necrosis factor-alpha decreased, cell growth was inhibited, cell proliferation, migration and invasion decreased significantly, and apoptosis increased, while si-sex determining region Y-box 2+ mitogen-activated protein kinase kinase kinase kinase 4 transfection could reverse the above trend. Sex determining region Y-box 2 silencing can activate the mitogen-activated protein kinase kinase kinase kinase 4 signal pathway, promote the proliferation, migration, and invasion of breast cancer cells and inhibit apoptosis.