MEX3A promotes triple negative breast cancer proliferation and migration via the PI3K/AKT signaling pathway.

Triple-negative breast cancer (TNBC) has the characteristics of fast growth, easy invasion, metastasis, poor prognosis, low tumor-free survival rate and overall survival rate. In this study, the RNA-binding protein MEX3A was selected by using the methods of TCGA database analysis, mRNA microarrays, and tissue chip immunohistochemistry experiments. The high expression of MEX3A is associated with malignancy and poor prognosis of TNBC. In addition, MEX3A knockdown can inhibit the growth and migration of TNBC cells while MEX3A overexpression shows the opposite effect. In vivo experiments, we also demonstrated that downregulating MEX3A can inhibit the tumorigenicity of TNBC cells. The mRNA microarrays and Ingenuity pathway analysis (IPA) were used to explore the downstream of MEX3A, and verified the relationship between PI3K/AKT signaling pathway and MEX3A. Additionally, we have simultaneously up-regulated MEX3A and treated with pathway inhibitors in vitro experiments and found that it can slow down the growth of TNBC cells. In short, we identified MEX3A as a tumor promoter, potential prognostic indicator and therapeutic target for TNBC, may function through the regulation of the PI3K/AKT signaling pathway.