The Influences On Tumor Angiogenesis Of Radiation Therapy, Mild Hyperthermia And Tumor Necrosis Factor

Background and Objectives: The objectives of this study were to evaluate the antiangiogenesis effects of fractionated RT, MHT and rmhTNF-α treatment. Using C57BL/6 mice bearing B16 melanoma, we observed the changes of MVD and the expression of VEGF in tumor tissues after different single or combined treatments. On the other hand, we analyzed the feasibility of contrast-enhanced CT in accessing the degree of tumor angiogenesis by correlating the perfusion index values and MVD of tumors.Methods: The B16 melanoma cells were transplanted s.c. into the right hind limbs of C57BL/6 mice. Experiments were performed when tumors had reached approximately 5~7mm in diameter. 64 mice were randomly assigned to 8 groups: control group, RT group, MHT group, rmhTNF-α group, RT+ MHT group, RT+ rmhTNF-α group, MHT + rmhTNF-α group and RT + MHT + rmhTNF-α group. Tumor perfusion indexs of 16 mice (control and RT groups) were estimated by assessing the contrast-enhanced CT changes and all mice were sacrificed by cervical dislocation 5 days after the completion of therapy. The MVD and VEGF expression rates were calculated and described by immunohistologic staining assays. Statistical significance was determined using SAS8.1 software.Results: The MVD values demonstrated significant decreases after RT, RT+MHT, RT +rmhTNF-α and RT + MHT + rmhTNF-α treatment. The rates of VEGF expression in RT, RT + rmhTNF- α and RT + MHT + rmhTNF-α groups were...