Long Noncoding RNA MALAT1 Functions as a Sponge of MiR-200c in Ovarian Cancer.

Abstract

Previous researches have revealed that alteration of non-coding RNAs expression level in malignancies can significantlymodify the course of diseases. Current study was aimed to investigate the biological functions of lncRNA MALAT1 and miR-200c, as well as the interaction between them. Quantitative real-time polymerase chain reaction (qRT-PCR) showed that lncRNA MALAT1 was overexpressed in ovarian cancer tissues and cell lines in compare to adjacent normal tissue and normal human ovarian surface epithelial cells (HOSEPiCs). Contrarily, miR-200c expression was significantly decreased in ovarian cancer, which is negatively correlated with MALAT1 expression. In addition, overexpression of lncRNA MALAT1 appeared to be related to worse prognosis and higher metastasis. In consistent with clinical outcomes, down-regulation of lncRNA MALAT1 suppressed the cell viability, migration and invasion abilities of ovarian cancer cell lines. Moreover, bioinformatics analysis suggested that3'-UTR of lncRNA MALAT1 and miR-200c have a complementarity region. Rescue experiments confirmed that miR-200c could reverse the tumor-suppressive effect of knock-down of lncRNA MALAT1 on ovarian cancer cells. Nevertheless, luciferase assays verified the existence of direct binding between miR-200c and lncRNA MALAT1. In general, results of this study indicated that lncRNA MALAT1 is a oncogene in ovarian cancer, involved in the regulation of cell viability, migration and invasion abilities of ovarian cancer cells, which achieved its biological function by regulating miR-200c expression. Therefore, lncRNA MALAT1 could be a promising prognostic biomarker and therapeutic target for ovarian cancer and its relation with miR-200c might be a starting point for future researches.