Usefulness of anti-tumor evaluation model combining rasH2 gene modified mouse with two-stage carcinogenesis model

Abstract

The transplantation model has an ectopic problem, the chemical carcinogenesis model takes longer time. Using a Tg-rasH2 mouse model with two-stage carcinogenesis model, we examined usefulness of this combination. Tg-rasH2 ♀ mice given ENU, and then BHT weekly for 5 weeks. For 2, 2, 9 mice at 5, 7 and 9 weeks after the first dosing BHT, tumor and PD-L1 were examined. At each necropsy, tumors were observed in 2, 2 and 9 cases. Tumor formation was 9 weeks in Umemura’s report (2006), but now it was observed 5 weeks with PD-L1 expression. The result suggests usefulness of this model.