Low Expression of miR-663a Indicates Poor Prognosis and Promotes Cell Proliferation, Migration, and Invasion in Breast Cancer.

Introduction Breast cancer is one of the most common malignant cancers among women worldwide. MicroRNA-663a (miR-663a) acts as a tumor suppressor gene involved in the development of various cancers. Objective The aim of this study was to reveal the clinical significance and biological function of miR-663a in breast cancer. Methods The expression of miR-663a in breast cancer tissues and cells was evaluated by reverse transcription-quantitative polymerase chain reaction. Kaplan-Meier survival and Cox regression analysis were performed to evaluate the prognostic significance of miR-663a in breast cancer. CCK-8 and Transwell assays were used to demonstrate the effect of miR-663a on breast cancer cell function. Results We confirmed that the expression of miR-663a was significantly downregulated in breast cancer tissue samples and cell lines. Low miR-663a expression was significantly associated with lymph node metastasis, TNM stage, subtypes, and poor survival in breast cancer patients, indicating that miR-663a is an independent prognostic factor for patients with breast cancer. Cell function experiments revealed that low miR-663a expression promoted cell proliferation, migration, and invasion in breast cancer. Conclusions All experimental results demonstrated that miR-663a acts as a tumor suppressor that inhibits the proliferation, migration, and invasion of breast cancer cells, and miR-663a may be a prognostic biomarker and therapeutic target for breast cancer.