Functional analysis of miR-1246 in colorectal cancer

Abstract

Background. Colorectal cancer (CRC) is currently one of the most prevalent cancer types worldwide and is the second leading cause of cancer-related mortality (Bray et al., 2018). Over the last years, CRC detection rates have improved; however, disease-related mortality remains very high (Bray et al., 2018). Despite increasing access to CRC screening programs in Lithuania and other EU countries, more precise methods for early non-invasive disease detection are very much needed (Kalager et al., 2020; Benard et al., 2018). MicroRNAs are known as post-transcriptional gene expression regulators and potential biomarkers. It has been shown that differential miR expressions allows to discriminate between normal and cancerous tissues, different stages and subtypes of cancer, including CRC (Di Leva et al., 2013; Schetter et al., 2012). Comprehensive miR analysis showed deregulated miR profiles in CRC. However, in order to understand the functional relevance of miR dysregulation, studies analysing their target genes are of a major importance. Objective. To determine target genes of colorectal cancer associated miR-1246 and its function in colorectal cancer pathogenesis. Methods. MTT, clonogenic, dual-light luciferase reporter gene, gene and protein expression assays were performed in SW620 and Caco-2 cell lines after cell transfection with hsa-miR-1246 mimic and inhibitor to determine miR-1246 impact in cell function changes and to confirm its target genes. Results. Reduced cell viability was observed in Caco-2 (28.1 % p = 0.02) and SW620 (28.2 % p = 0.001) cell lines 72 hours after transfection with miR-1246 inhibitor. Clonogenic test results demonstrated that inhibition of miR-1246 decreased colony number in Caco-2 (38.3 % p = 0.005) cell line, while overexpression of miR-1246 had no significant effect on colony formation in both Caco-2 and SW620 cell lines. CRC-associated putative target-oncogenes of miR-1246 were ret [...].