Immunohistochemistry Evaluation of the Effect in Vivo of Tumor Necrosis Factor(TNF)-αon Blood VesselDensity in Murine Fibrosarcoma

[摘要] Purpose: Angiogenesis is essential for tumor growth and metastases, thus bestowing obvious importance upon methodologieswhich could enable its inhibition.Materials: C57BL/6 female mice bearing a subcutaneous (s.c.) MCA205 fibrosarcoma were used.Methods: Ten mice were divided equally into two groups. One group was injected intraperitoneally (i.p.) with 10 μg tumornecrosis factor-α (TNF-α and the other (controls) with Hanks balanced salt solution (HBSS). Tumor growth was monitoredat least twice weekly. The number of endothelial cells in the blood microvessels was assessed by immunohistostaining onparaffin-embedded tumor tissue sections using vascular endothelial growth factor (VEGF) and Factor 8 antibodies.Expression of the p53 gene was similarly assessed by immunohistostaining.Results: Injection of 10 μg TNF-α into the tumor-bearing mice reduced the number of endothelial cells in the bloodmicrovessels by 46% on day 3 post-injection which was accompanied by an increase (by 37%) in the expression of p53 inthese cells. It also inhibited tumor growth compared to the HBSS-injected group starting at 17 days post-cytokine injection.Discussion: The antitumorin vivoeffect exerted by TNF-α on established murine sarcoma s.c. tumors may be due to anearlier effect of the cytokine on the tumor's blood microvessels, probably through an apoptotic mechanism involving thep53 gene.

[学科分类] 肿瘤学