MiR-299-5p targets cell cycle to promote cell proliferation and progression of osteosarcoma.

Abstract

Osteosarcoma is a common primary bone tumor with high mortality. MicroRNA (miRNA, miR) is a small RNA with 20-25 nucleotides, which could regulate diverse biological processes by targeting 3'-UTR of gene to degrade it. MiR-299-5p has been reported to participate in the progression of many diseases, but the role in osteosarcoma is still uncertain. The aim of this work was to investigate the expression of miR-299-5p in osteosarcoma and its clinical significance. The datasets of osteosarcoma miRNA was searched in Gene Expression Omnibus (GEO) datasets, including GSE65071, GSE39040, and GSE39055. Osteosarcoma U2 and MG-63 cells were cultured in our study. Cell proliferation level after transfection was detected by using Cell Counting Kit-8 (CCK8) and colon formation assay. Cell cycles were explored using flow cytometer and cell protein expression levels after that the transfection was detected by Western blotting. We found that ROC curve analysis showed that miR-299-5p was a sensitivity diagnostic criteria and GSEA indicated that miRNA-299-5p may regulate cell cycle. Gain of function assay showed that miR-299-5p promotes cell cycle transition and proliferation. Reversely, the opposite results were observed with loss of function assay. At last, Western blotting assay showed that miR-299-5p may promote cell cycle transition by regulating CDK family.