刚地弓形虫对荷瘤小鼠肿瘤组织微血管生成的抑制作用

摘 要：目的 观察刚地弓形虫感染对BALB/c小鼠ct26细胞皮下移植瘤血管生成的抑制作用及其作用机理。方法 建立刚地弓形虫感染的小鼠结肠癌ct26皮下移植瘤模型，观察弓形虫感染对小鼠的生存延长率、对肿瘤的质量抑制率，并采用免疫组化方法检测弓形虫感染对肿瘤组织MVD、VEGF、TSP-1表达的影响。结果 弓形虫感染的小鼠生存时间比对照组长（P<0.05），生存延长率为57.45%，肿瘤质量抑制率为47.23%；弓形虫感染的小鼠肿瘤组织中MVD及VEGF表达水平低于对照组（P=0.005，P=0.03），TSP-1表达高于对照组（P=0.005）。结论 弓形虫感染能抑制荷瘤小鼠肿瘤组织微血管生成；下调VEGF及上调TSP-1与弓形虫感染抗肿瘤血管生成有关。

Inhibitory effect of Toxoplasma gondii on angiogenesis of tumor tissue on transplanted carcinoma in mice

To investigate the inhibitory effect of Toxoplasma gondii on angiogenesis of tumor tissue in transplanted carcinoma of colon ct26 ceils in BALB/c mice, the tumor model of BALB/c mice was established by injecting the co-culture of mouse colon cancer cells ct26 with tachyzoites of T. gondii RH strain, and observed the survival time and the tumor inhibitory rate of tumor-bearing mice. The microvessel density and expressions of gene vascular endothelial growth factor （VEGF） and thrombospondin-1（TSP-1） in tumor tissue were evaluated by methods of immunohistochemistry. The survival duration of mice in group infected with T. gondii was longer than that of the control group（P〈0.05）. The extension rate of mice was 57.45% and the tumor inhibitory rate was 47.23%. The expressions of gene VEGF in tumor tissue infected with T. gondii was less than that of the control group（P=0. 005 ,P=0. 03） ,but the expressions of gene TSP-1 was more than that of the control group （P=0. 005）. These results suggest that the mice infection with T. gondii could inhibit tumor by blocking the angiogenesis of it,which are related to the reducing expression of gene VEGF and enhancing expression gene of TSP-1.