Expression of HIF-1α and its relationship with angiogenesis in osteosarcoma

Abstract

Objective:To investigate the expression of HIF-1αand its relationship with angiogenesis in osteosarcoma.Methods: Osteosarcoma MG-63 cells were cultured in vitro under hypoxia and mimic hypoxia conditions.Thirty paraffin-embedded osteosarcoma tissues and 20 fresh frozen osteosarcoma specimens were collected.The mRNA and protein expression of HIF-1αand VEGF were detected by RT-PCR,Western blotting,ELISA,and immunohistochemistry methods.The mean vessel density(MVD)were also calculated.Results:The mRNA level of HIF-1αhad no change under hypoxia and minic hypoxia conditions,whereas the protein expression was increased dramaticaly.The mRNA and protein expression of VEGF was significantly increased under hypoxia and minic hypoxia conditions.The positive rate of HIF-1αmRNA(90%)and VEGF(100%)in 20 fresh frozen tissues were higher than those of the para-tumor tissues(P0.05).The positive rates of HIF-1αand VEGF protein in paraffin-embedded osteosarcoma were 86.7% and 93.3%,respectively,significantly higher than those in the para-tumor tissues(6.7 %,26.7%,P0.05).Spearman related analysis demonstrated that the expression of HIF-1α(P=0.005,r=0.767) and VEGF(P0.002,r=0.701)had a positive relation with MVD.Conclusion:HIF-1αis overexpressed in osteosarcoma and might be closely associated with tumor angiogenesis.Overexpression of HIF-1αmight indicate a poor prognosis of osteosarcoma.