Establishment of a Novel Bladder Cancer Xenograft Model in Humanized Immunodeficient Mice

BACKGROUND/AIMS: The aim of this study was to develop a novel model by transplanting human bladder cancer xenografts into humanized immunodeficient mice (SCID). METHODS: The animals first underwent sublethal irradiation and then were subjected to simultaneous transplantation of human lymphocytes (5 × 10⁷ cells/mouse i.p.) and human bladder cancer cells (3 × 10⁶ cells/mouse s.c.). RESULTS: The xenografts developed in all 12 mice that had received bladder cancer BIU-87 cells, and the tumor specimens were evaluated histologically. All 6 model mice expressed human CD3 mRNA and/or protein in the peripheral blood, spleens and xenografts. The mean proportion of human CD3+ cells was 19% with a level of human IgG 532.4 µ/ml in the peripheral blood at Week 6 after transplant inoculation. The re-constructed human immune system in these mice was confirmed to be functional by individual in vitro testing of their proliferative, secretory and cytotoxic responses. CONCLUSION: The successful engraftment of the human bladder cancer xenografts and the establishment of the human immune system in our in vivo model described here may provide a useful tool for the development of novel therapeutic strategies targeting at bladder cancer.