Long non-coding RNA MALAT1 promote triple-negative breast cancer progression by regulating miR-204 expression

Recent studies demonstrated that lncRNAs have a critical role in the regulation cancer progression and metastasis. However, little is known about the mechanism through which MALAT1 exerts its oncogenic activity, and the interaction between MALAT1 and microRNA remains largely unknown. In the present study, we reported that MALAT1 was up-regulated in triple-negative breast cancer (TNBC) tissues. Knockdown of MALAT1 inhibited proliferation, motility and increased apoptosis in vitro. In vivo study indicated that knockdown of MALAT1 inhibited tumor growth. Patients with high MALAT1 expression had poorer overall survival time than those with low MALAT1 expression. In addition, our findings demonstrate a reciprocal negative control relationship between MALAT1 and miR-204: downregulation of MALAT1 increased expression of miR-204, while overexpression of miR-204 decreased MALAT1 expression. We proposed that MALAT1 exerted its function through the miR-204. In summary, we proposed that MALAT1 may be a target for TNBC therapy.