Antitumor Effect of miR-1294/Pyruvate Kinase M2 Signaling Cascade in Osteosarcoma Cells

Background: MicroRNAs (miRNAs) can act as negative regulators of gene expression, and play a crucial role in cancer progression. The aim of this study was to investigate the role of miR-1294/pyruvate kinase M2 (PKM2) axis in osteosarcoma cells in vitro and in vivo. Methods: The function of miR-1294 and its association with PKM2 in osteosarcoma cells were studied by real-time PCR, CCK-8, Western blot, scratch test, transwell assay, flow cytometry, and dual-luciferase reporter assays. The effect of miR-1294 on tumor growth in vivo was evaluated in a subcutaneous xenograft model of osteosarcoma. Results: miR-1294 was downregulated in osteosarcoma cells. Forced overexpression of miR-1294 inhibited cell proliferation, migration, and invasion, and induced G0/G1 arrest and apoptosis. Consistently, protein expression levels of proliferating cell nuclear antigen, c-Myc, cyclin D1, active matrix metalloproteinase 2, and active matrix metalloproteinase 9 were decreased, and cleaved caspase 3 and cleaved PARP were increased following miR-1294 overexpression. Moreover, we demonstrated that PKM2 was a target of miR-1294 in osteosarcoma cells, and the effects caused by miR-1294 mimic were reversed by the overexpression of PKM2. Furthermore, we found that upregulation of miR-1294 inhibited tumorigenesis of osteosarcoma cells in vivo, which was accompanied by downregulation of PKM2. Conclusion: Our results revealed that miR-1294/PKM2 signaling cascade exerts important roles in the regulation of tumor progression, implying that this pathway may serve as a potential therapeutic target in osteosarcoma.