Expression of miR-21 in osteosarcoma and its clinical significance

[Objective]To explore the expression of miR-21 in osteosarcoma and the correlation between miR-21 and clinicopathological characteristics.[Method]We analyzed the level of miR-21 expression in osteosarcoma tissues,matched it to the normal bone tissues from 42 patients(including 12 sets of matched primary or metastatic tumor samples from the same patients) by real-time RT-PCR and evaluated the clinical relevance of miR-21.[Result]Totally 38 of 42(90.5%) showed a higher expression level of miR-21 in tumor tissues than in matched normal tissues.Moreover,analysis of paired primary and metastatic osteosarcoma samples from 12 patients showed an increase in miR-21 expression levels in metastases.Besides,higher expression of miR-21 had a significant correlation with reduced survival.[Conclusion]Our results suggest that overexpression of miR-21 potentially contributes to human osteosarcoma metastasis and acts as one of prognostic factors.