Expression and clinical significance of cyclooxygenase-2 and microRNA-143 in osteosarcoma

The aim of the present study was to investigate the expression profiles of cyclooxygenase (COX)-2 and microRNA (miRNA)-143 in the tumor tissue and blood samples of patients with osteosarcoma, and their involvement in the disease pathogenesis. Tumor tissue and blood samples were obtained from 46 patients with osteosarcoma (stages I-III). Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot analyses were performed to detect the mRNA and protein expression of COX-2, respectively, in these samples. The expression of miRNA-143 in the tumor tissue and blood samples was assessed using RT-qPCR. The results showed that, compared with the normal control subjects, the mRNA and protein expression levels of COX-2 in the tumor tissue and blood samples of patients with osteosarcoma were increased. Among the patients with osteosarcoma, increases in the COX-2 mRNA and protein levels were observed with progressing disease severity (from stage I to stage III), suggesting the involvement of COX-2 in the disease pathogenesis. By contrast, the expression of miRNA-143 decreased as the disease progressed, which was the opposite trend to the COX-2 expression, indicating that miRNA-143 and COX-2 may play different roles in the disease pathogenesis. In conclusion, COX-2 expression in the tumor tissue and blood samples of patients with osteosarcoma increases significantly along with the degree of tumor malignancy, and this is accompanied by a decreased expression of miRNA-143; therefore, a negative correlation between COX-2 and miRNA-143 may exist in the progression of osteosarcoma.