MicroRNAs (miRNAs/miRs) are a type of highly conserved, small non-coding RNA that are vital to the post-transcriptional regulation of gene expression via base pairing with target mRNA 3'-untranslated regions (3'-UTRs). Several studies have indicated that the abnormal expression of miRNAs occurs frequently in human osteosarcoma (OS). In the present study, the role of miR-26a in the progression and metastasis of OS was investigated using reverse transcription-quantitative polymerase chain reaction, a luciferase activity assay, cell viability assay, in vitro migration and invasion assays, transfection and western blot analysis. miR-26a was upregulated in OS tissues and cell lines, and the expression of miR-26a was indicated to affect the proliferation, migration and invasion of OS Saos-2 cells. At the molecular level, the results showed that glycogen synthase kinase-3β (GSK-3β) was identified as a target of miR-26a, and the ectopic expression of miR-26a inhibited GSK-3β by directly binding to the 3'-UTR. Therefore, the expression of miR-26a was negatively correlated with GSK-3β in the OS tissues. These data suggest that miR-26a is significant in the proliferation of human OS cells due to the direct regulation of Wnt/β-catenin signaling.
Keywords: cell proliferation; glycogen synthase kinase-3β; microRNA-26a; microRNAs; osteosarcoma.