miR-425-5p is associated with poor prognosis in patients with breast cancer and promotes cancer cell progression by targeting PTEN

Breast cancer (BC) is the most common invasive cancer in women, and it imposes a heavy burden on patients. microRNAs (miRNAs/miRs) have been found to play an important role in the development of tumors, but their role in the malignant progression of BC is unclear. In the present study, the expression level of miR-425-5p was examined in patients with BC, and its association with prognosis was investigated. In vitro experiments were performed to examine role of miR-425-5p in the development of BC cells. A downstream target gene of miR-425-5p was predicted using a miRNA target prediction tool and validated with a luciferase reporter assay. It was found that miR-425-5p expression was increased in BC tissues and cell lines, and was associated with tumor size, clinical stage, lymph node metastasis, distant metastasis and poor overall survival in patients with BC. Knockdown of miR-425-5p in BC cell lines inhibited proliferation and migration. PTEN was identified as a downstream target gene of miR-425-5p. Overexpression of PTEN was demonstrated to partially inhibit the promotional effect of miR-425-5p on cell proliferation and migration. Taken together, miR-425-5p is associated with poor prognosis, and promotes cell proliferation and migration via PTEN. Thus, miR-425-5p may serve as a therapeutic and prognostic marker for BC.