MicroRNA‑20a promotes the proliferation and cell cycle of human osteosarcoma cells by suppressing early growth response 2 expression.

MicroRNAs (miRNAs) are crucial in cancer development. However, the underlying mechanisms of miRNAs in osteosarcoma (OS) remain largely uncharacterized. The present study investigated the role of miR‑20a in OS cell proliferation. It was determined that miR‑20a expression is markedly upregulated in OS tissues and cells compared with the matched adjacent normal tissues and h‑FOB human osteoblast cell lines. Ectopic expression of miR‑20a promoted the proliferation and anchorage‑independent growth of OS cells, whereas inhibition of miR‑20a reduced this effect. Bioinformatics analysis further revealed early growth response 2 (EGR2), as a potential target of miR‑20a. Data from luciferase reporter assays showed that miR‑20a directly binds to the 3'‑untranslated region (3'‑UTR) of EGR2 mRNA and represses expression at the transcriptional and translational levels. In functional assays, miR‑20a promoted OS cell proliferation and the cell cycle, which could be suppressed by an inhibitor of miR‑20a. In conclusion, the data provide compelling evidence that miR‑20a functions as an onco‑miRNA, which is important in promoting cell proliferation in OS, and its oncogenic effect is mediated primarily through direct suppression of EGR2 expression.