The Expression Of Hypoxia Inducible Factor-1a(HIF-1α) And Apparent Diffusion Coefficient (ADC) In Xenograft Tumors Of Athymic Mice And Their Correlation

Objective：To investigate the expression of Hypoxia inducible factor-1a(HIF-l α) and apparent diffusion coefficient (ADC) in xenograft tumorsof athymic mice and their correlation.Methods： Thirty-six athymic mice bearing human nasopharyngealcarcinoma cell line CNE-2randomly divided into six group,controlgroup, another five group: give6MVX-ray,15Gy irradiation,calledafter irradiation,1day,2day,3day,5day,and7day.The xenograft tumorsADC value were detected before and after irradiation. The expressionof HIF-1α detected by MaxvisionTMimmunohistochemical method.The HIF-1αmRNA and protein were evaluated by real-time quantitative PCR andwestern-blot.To investigate the expression of HIF-lα and apparentdiffusion coefficient (ADC) and their correlation before and afterirradiation.Results：(1)The expression of HIF—lα were very high in xenografttumors of athymic mice. The positive expression rates of HIF-1α were69.4%（2）The expression of HIF—lα mRNA were much higher afterirradiation in the2day and3day than before irradiation(P＜0.01）； whilemuch lower after irradiation in the7day than before irradiation(P＜0.01）.（3）The expression of HIF—lα protein were much higher afterirradiation in the2day than before irradiation(P＜0.01）；while muchlower after irradiation in the5day and7day than before irradiation(P＜0.05）（4）The ADC value were much lower after irradiation in the2day than before irradiation(P＜0.05）；while much higher after irradiationin the7day than before irradiation(P＜0.05）.(5)HIF-1αmRNA levels were negatively correlated with ADC value (r=-0．727，P<O．01)； HIF-1aprotein levels were negatively correlated with ADC value (r=-0.618，P<O．01).Conclusions： The expression of HIF—lα were very high in xenografttumors of athymic mice.The expression of HIF—lα mRNA were much higherafter irradiation in the2day and3day than before irradiation； whilemuch lower after irradiation in the7day than before irradiation.Theexpression of HIF—lα protein were much higher after irradiation in the2day than before irradiation；while much lower after irradiation in the5day and7day than before irradiation. The value of ADC were much lowerafter irradiation in the2day than before irradiation；while much higherafter irradiation in the7day than before irradiation.The expression of HIF-lαand ADC value were closely related inxenograft tumors of athymic mice.