MicroRNA-4317 predicts the prognosis of breast cancer and inhibits tumor cell proliferation, migration, and invasion.

Previous researches have indicated that miR-4317 was aberrantly expressed in several tumors. However, the potential role of miR-4317 in breast cancer is still unclear. The aim of this study was to investigate the potential role of miR-4317 in breast cancer. The relative expression levels of miR-4317 were detected in breast cancer tissues and cell lines using qRT-PCR analysis. The Kaplan-Meier survival curve and multivariate Cox regression analyses were used to investigate the prognostic significance of miR-4317 in breast cancer. CCK-8 and Transwell assays were performed to evaluate the effects of miR-4317 on cell proliferation, migration, and invasion. The results showed that miR-4317 expression was decreased in breast cancer tissues and cell lines. Downregulation of miR-4317 was significantly associated with lymph node metastasis, TNM stage, and poor prognosis. Overexpression of miR-4317 inhibited proliferation, migration, and invasion of breast cancer cells, while downregulation of miR-4317 exhibited the opposite effects. MYD88 may be a direct target of miR-4317. The results suggest miR-4317 may play a tumor suppressor role in breast cancer and inhibit proliferation, migration, and invasion of breast cancer cells by targeting MYD88. The findings provide novel evidence of miR-4317 as a potential prognostic biomarker and therapeutic target for breast cancer.