Data from Elevated miR-182-5p Associates with Renal Cancer Cell Mitotic Arrest through Diminished <i>MALAT-1</i> Expression

Abstract

<div>Abstract<p>The molecular heterogeneity of clear cell renal carcinoma (ccRCC) makes prediction of disease progression and therapeutic response difficult. Thus, this report investigates the functional significance, mechanisms of action, and clinical utility of miR-182-5p and metastasis-associated lung adenocarcinoma transcript 1 (<i>MALAT1/NEAT2</i>), a long noncoding RNA (lncRNA), in the regulation of kidney cancer using human kidney cancer tissues as well as <i>in vitro</i> and <i>in vivo</i> model systems. Profiling of miR-182-5p and <i>MALAT-1</i> in human renal cancer cells and clinical specimens was done by quantitative real-time PCR (qPCR). The biological significance was determined by series of <i>in vitro</i> and <i>in vivo</i> experiments. The interaction between miR-182-5p and <i>MALAT-1</i> was investigated using luciferase reporter assays. In addition, the effects of miR-182-5p overexpression and <i>MALAT-1</i> downregulation on cell-cycle progression were assessed in ccRCC cells. The data indicate that miR-182-5p is downregulated in ccRCC; the mechanism being CpG hypermethylation as observed from 5-Aza CdR treatment that decreased promoter methylation and expression of key methylation regulatory genes like <i>DNMT1, DNMT3a</i>, and <i>DNMT3b</i>. Overexpression of miR-182-5p–inhibited cell proliferation, colony formation, apoptosis, and led to G<sub>2</sub>–M-phase cell-cycle arrest by directly targeting <i>MALAT-1</i>. Downregulation of <i>MALAT-1</i> led to upregulation of p53, downregulation of CDC20, AURKA, drivers of the cell-cycle mitotic phase. Transient knockdown of <i>MALAT-1</i> mimicked the effects of miR-182-5p overexpression. Finally, overexpression of miR-182-5p decreased tumor growth in mice, compared with controls; thus, demonstrating its antitumor effect <i>in vivo</i>.</p><p><b>Implications:</b> This is the first study that offers new insight into role of miR-182-5p/<i>MALAT-1</i> interaction on inhibition of ccRCC progression. <i>Mol Cancer Res; 16(11); 1750–60. ©2018 AACR</i>.</p></div>