As one common malignant bone cancer, osteosarcoma is mainly occurred in young people with increasing incidences. Current treatment of osteosarcoma includes surgery and chemo-/radio-therapy. Due to the unclear pathogenesis mechanism, the overall treatment efficacy is still not satisfactory. As anti-apoptotic molecule Bcl-2 has been suggested to be related with osteosarcoma and is regulated by miR-143, we thus investigated the correlation between miR-143 and Bcl-2 in osteosarcoma patients, in an attempt to elucidate the role of miR-143 in cancer occurrence. Real-time fluorescent RT-PCR was used to quantify expression levels of miR-143 and Bcl-2 from a total of 5 osteosarcoma patients, along with protein contents determination by Western blotting. In vitro study was also performed to detect Bcl-2 expression and cell apoptosis via silencing or over-expressing miR-143 in cultured osteosarcoma cells. MiR-143 showed down-regulation in osteosarcoma tissues. Bcl-2, however, had elevated expression in cancer cells when compared to adjacent tissues (P<0.05). In cultured cells, Bcl-2 expression level was also potentiated after knock-down of miR-143, while those cells with miR-143 over-expression had depressed Bcl-2 levels. Those cells transfected with miR-143 mimics had higher percentage of apoptotic cells. MiR-143 can regulate the expression of Bcl-2 gene in osteosarcoma cells, and mediate the apoptotic process, thereby playing a critical role in the pathogenesis of osteosarcoma.
Keywords: Bcl-2; MiR-143; Osteosarcoma; Real-time fluorescent PCR; Western blotting.