Abstract:

[Abstract] Objective   To investigate the effect of HIF-2a silencing by transfection of siRNA into MG-63cells un?der hypoxia.Methods   HIF-2αexpression level in MG-63cells under hypoxia was determined by Western Blot. Small in?
terfering RNA (siRNA) was used to construct MG-63/siHIF-2α（siHIF-2α）cells and control MG-63/scramble(NC) cells.The expression levels of HIF-2α, Vascular endothelial growth factor (VEGF), p-Erk/ErK and Mcl-1in MG-63, NC and si?HIF-2αcells was determined by Western Blot. NC and siHIF-2αcells were cultured under hypoxia. Cell viability was as?sessed by MTT assay. Migration was identified by scratch migration assay. Tumor formation was identified by clone formation assay. Nude mouse subcutaneous xenograft model was used to investigate tumor development in vivo.Results   Hypoxia im?proved HIF-2αexpression in MG-63cells in a time-dependent manner (F=2037.412，P＜0.001). HIF-2αexpression un?der hypoxia in siHIF-2αcells was lower than that in NC cells (P＜0.01). Cell viability of siHIF-2αcells under hypoxia for12h and24h were lower than that in NC cells (P＜0.05orP＜0.01). The relative width of scratch in siHIF-2αgroup under hypoxia for12h and24h were larger than that in NC group (P＜0.01orP＜0.01). When cell counts reach 1000-5000, the clone formation rates of siHIF-2αcells were lower than that in NC cells (P＜0.05orP＜0.01). The expression of VEGF, pErk/Erk and Mcl-1protein under hypoxia in siHIF-2αcells was lower than that in NC cells(P＜0.01). Tumor sizes, weights and density of siHIF-2αgroup in nude mice were suppressed compared with those in NC group (P＜0.01). Conclusion   Blocking HIF-2αsignal pathway warrants its investigation as a potential strategy in osteosarcoma treatment.

Key words: Osteosarcoma, cell line, tumor, RNA, small interfering, gene silencing, neoplasm transplantation, 小鼠