RESUMEN

Abstract Deregulation of miRNA expressions was identified as a novel feature of tumor biology in Ewing sarcoma (EWS). The aim was to evaluate the regulatory role of miR-129-2-3p in EWS cell lines and human EWS tissue samples. EWS cell lines TC-71, TC-106, and CHLA-99 were used in the study and real-time PCR was utilized to investigate the functional role of tumor suppressor mir-129-2-3p and miR-129-2-3p levels in the cells. Proliferation, migration, invasion and apoptosis assays were carried out within the scope of functional in vitro studies. Expression levels of CDK6 and SOX4, which are miR-129-2-3p target genes, were examined. Moreover, the change in expression levels of miR-129-2-3p in EWS tumor tissues was also examined. It was determined that miR-129-2-3p expression markedly diminished in all the studied cell lines. In addition, miR-129-3p was found to decrease in proliferation, migration, invasion and apoptosis assays in all EWS cell lines. CDK6 and SOX4 levels were also decreased in miR-129-2-3p transfected cell lines. It was found that miR-129-2-3p levels were significantly decreased in EWS tumor tissue samples compared to the corresponding adjacent normal tissue samples. In line with the results of our current study, where the possible function of miR‐129-2-3p in EWS cell lines was examined, for the first time in the literature miR-129-2-3p was shown to have low expression level in EWS lines and EWS tumor tissue samples, and to provide a tumor suppressor effect.