| Abstract: | Although progress in clinical and basic research has significantly increased our understanding of breast cancer, little is known about the molecular mechanism underlying breast cancer metastasis. Identification of effective therapeutic targets to prevent breast cancer metastasis is urgently needed. The function of mi R-503-3p has been investigated in other cancers, but its role in breast cancer remains undefined.Here, we found that mi R-503-3p was overexpressed in breast cancer tissue and plasma compared with adjacent normal breast tissue and with plasma from healthy individuals. Moreover, we identified mi R-503-3p to be an oncogene of breast cancer cell proliferation, migration and invasion. Upregulation of mi R-503-3p in breast cancer cells inhibited expression of epithelialemesenchymal transition(EMT)-related protein SMAD2 and the epithelial marker protein E-cadherin by directly binding to their m RNA30 untranslated region, whereas increased expression of mesenchymal marker proteins, including vimentin and N-cadherin. Taken together, our findings support a critical role for mi R-503-3p in induction of breast cancer EMT and suggest that plasma mi R-503-3p may be a useful diagnostic biomarker for breast cancer. |
