Development of gnotobiote mice for cancer research

采用从人类和小鼠粪便中分离的多种肠道细菌进行口服接种，制备了具有人类癌症基因c-Ha-ras基因的克隆转基因小鼠。我们比较了不同类型小鼠皮下注射甲肼后结肠肿瘤的发生率。各组转基因小鼠的肿瘤发生率均高于对照小鼠。花成分的差异影响肿瘤的发生。在某些情况下，花细菌刺激肿瘤的形成，在某些情况下抑制肿瘤的形成。肿瘤发生率、β -葡萄糖醛酸酶活性和次级胆汁酸的产生之间没有关系。

Gnotobiotic transgenic mice with human cancer gene, c-Ha-ras gene, were Produced by oral inoculation with various intestinal bacteria isolated from human and mouse feces. We compared the colon tumor incidence after subcutaneous injection with dymetilhydrazin among various types of gnotobiotic mice. The tumor incidence of transgenic mice was higher than control mice in each group. The differences of floral composition affected the tumor incidence. In some cases floral bacteria stimulated the formation of tumors and in some cases inhibited. there were no relationship among tumor incidence, beta-glucuronidase activity and production of secondary bile acids.