MiR-300 regulate the malignancy of breast cancer by targeting p53.

Abstract

OBJECTIVE: In this study, we investigated the role of miR-300 in regulating cell proliferation and invasion of breast cancer (BC) cells. METHODS: MicroRNA and protein expression patterns were compared between breast cancer tissue and normal tissue and between two different prognostic groups. The up-regulation of miR-300 was confirmed by real-time reverse transcription polymerase chain reaction and its expression was analyzed in MCF-7 breast cancer cells. RESULTS: We observed that miR-300 expression was frequently and dramatically up-regulated in human breast cancer tissues and cell lines compared with the matched adjacent normal tissues and cells. We further showed that transient and stable over-expression of miR-300 could promote cell proliferation and cell cycle progression. Moreover, p53, a key inhibitor of cell cycle, was verified as a direct target of miR-300, suggesting that miR-300 might promote breast cancer cell proliferation and invasion by regulating p53 expression. CONCLUSION: Our findings indicated that miR-300 up-regulation might exert some sort of antagonistic function by targeting p53 in breast cancer cell proliferation during breast tumorigenesis.