HIF-1α Silencing Inhibits the Growth of Osteosarcoma Cells by Inducing Apoptosis

Abstract Osteosarcoma (OS) is a malignant tumor of mesenchymal origin, which is generally locally aggressive and tends to produce early systemic metastases. Therefore, an identification of a novel therapeutic target is required. We investigated the effect of small interfering RNA (siRNA) targeting hypoxia-inducible factor 1α (HIF-1α) on the growth of Osteosarcoma MG-63 and U2-OS cells. Two cell-lines were transfected with various concentrations of HIF-1α or control siRNA, and the effect on HIF-1α expression was analyzed by using quantitative polymerase chain reaction and western blot analysis. The effects of HIF-1α siRNA on growth inhibition and apoptosis were then evaluated by standard methods. HIF-1α siRNA treatment reduced HIF-1α mRNA and protein expression in MG-63 and U2-OS cells significantly. The downregulation of HIF-1α expression upregulated caspase-3 expression subsequently inhibited the growth of MG-63 and U2-OS cells and induced apoptosis of the two cells. Our in vitro data indicate that the downregulation of HIF-1α is capable of suppressing OS cells growth, through the induction of apoptosis. HIF-1α inhibition may be a new strategy for the treatment of Osteosarcoma.