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

BACKGROUND: microRNAs (miRNAs) are ubiquitously dysregulated in numerous tumor cell types, including melanoma cells. The anti-tumor effect 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 were assessed by qRT-PCR. Cell migration and invasion were analyzed by wound healing and transwell assays, respectively. Expression levels of biomarkers of epithelial–mesenchymal transition were determined by Western blot. Luciferase vectors containing wildtype or mutant miR-509-3p binding site were constructed, and then dual-luciferase reporter assay. 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–mesenchymal transition of melanoma cells was repressed by miR-509-3p, along with increased α-catenin/E-cadherin (P < .001) and decreased vimentin/fibronectin (P < .001). CTHRC1 (collagen triple helix repeat containing 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 inhibition of melanoma cell migration (P < .001), invasion, and epithelial–mesenchymal transition. CONCLUSION: miR-509-3p suppressed the biological function of melanoma cells through negatively regulating CTHRC1, shedding light on miR-509-3p as a potential candidate for melanoma therapeutics and treatments.