MicroRNA-191 promotes osteosarcoma cells proliferation by targeting checkpoint kinase 2.

MicroRNAs (miRNAs) are small noncoding RNAs of 19-25 nt that can regulate gene expression at a posttranscriptional level. Increasing evidence indicates that miRNAs participate in almost every step of cellular processes and are often aberrantly expressed in human cancer. The aim of this study was to investigate the functional significance of miR-191 and to identify its possible target genes in osteosarcoma cells. Here, we found that the expression level of miR-191 was increased in osteosarcoma tissues in comparison with the adjacent normal tissues. The enforced expression of miR-191 was able to promote cell proliferation in Saos-2 and MG62 cells, while miR-191 antisense oligonucleotides blocked cell proliferation. At the molecular level, our results further revealed that expression of tumor suppressor gene, checkpoint kinase 2, was negatively regulated by miR-191. Therefore, we consider that miR-191 act as an onco-MicroRNA for osteosarcoma and it would offer a new way in molecular targeting cancer treatment.