miR-509-3p Suppresses Migration, Invasion, and Epithelial– Mesenchymal Transition in Melanoma Cells by Targeting CollagenTriple Helix Repeat Containing 1

Abstract

Background: microRNAs (miRNAs) are ubiquitously dysregulated innumerous tumor cell types, including melanoma cells. The anti-tumoreffect of miR-509-3p was widely evaluated in various cancers. Aims: To determine the functional role of miR-509-3p in melanoma. Study Design: Cell culture study. Methods: Expression of miR-509-3p in melanoma cell models wereassessed by qRT-PCR. Cell migration and invasion were analyzed bywound healing and transwell assays, respectively. Expression levels ofbiomarkers of epithelial–mesenchymal transition were determined byWestern blot. Luciferase vectors containing wildtype or mutant miR 509-3p binding site were constructed, and then dual-luciferase reporterassay. Results: Dysregulated miR-509-3p level was found in melanoma cells.Elevated miR-509-3p expression suppressed melanoma cell migration(P < .001) and invasion (P < .001) capacities. Epithelial–mesenchymaltransition of melanoma cells was repressed by miR-509-3p, along withincreased α-catenin/E-cadherin (P < .001) and decreased vimentin/ fibronectin (P < .001). CTHRC1 (collagen triple helix repeat contain ing 1) contained a potential binding site for miR-509-3p, and miR 509-3p decreased protein expression of CTHRC1 in melanoma cells(P < .001). CTHRC1 promoted melanoma cell migration and invasion(P < .001), as well as contributed to epithelial–mesenchymal transition.Increased CTHRC1 expression attenuated miR-509-3p-induced inhibi tion of melanoma cell migration (P < .001), invasion, and epithelial– mesenchymal transition. Conclusion: miR-509-3p suppressed the biological function ofmelanoma cells through negatively regulating CTHRC1, shedding lighton miR-509-3p as a potential candidate for melanoma therapeutics andtreatments.