Study On The Influence And Machanism Of Ionization Radiation Of Different Dose On Microenvironment Of SKOV3Transplanted Tumor Of Athymic Mouse

Objective: To investigate the infulence of ionization of different dose on SKOV3tumor microenvironment and to probe its mechanism so as to improve the treatment efficacy of radiotherapy.Methods: Athymic mouses transplanted SKOV3ovarian cancer tumor are randomly divided into four groups:namely the control group(Group A),low dose irradiation group (Group B),high dose irradiation(Group C) and combined irradiation group(Group D).Group B:Utilizing X-rays produced in linear accelerator of which the radiation dose is300cGy/min to irradiate the tumor locally with50cGy.Group C: Irradiating the tumor locally with600cGy in the same condition of irradiation as group B.Group D:irradiating the tumor with50cGy first and600cGy after24hours. quantitative RT-PCR was used to test the expression of HIF1-a mRNA、P53mRNA、VEGF mRNA in the tumor tissue of different groups. Western blotting was used to tesify the protein expression level of three genes above.Result: The tissue hypoxia condition of four groups ranged from light to heavy is Group B,Group A,Group D and Group C. The expression of HIF1-α mRNA and VEGF mRNA of each group has great significant statistical differences(F=202.567,85.481P<0.05), The expression of t HIF1-α and VEGF in Group B is much lower than that of Group A(P<0.05). In contrary, the expression in Group D is higher than Group A(P<0.05).We found that no significant statistical differences occurred in the expression of HIF1-α and VEGF in Group D and Group A. Western blotting analysis result have been verified the protein level of the previous genes. Conclusion:1.. Low-dose irradiation could improve the condition of tissue hypoxia.2、The mechanism of this phenomenon is probably related to the downregulated expression of HIF1-α,P53,VEGF mRNAo...