Orthotopic implantation of primary N-[4-(5-Nitro-2-furyl)-2-thiazolyl]formamide-induced bladder cancer in bladder submucosa: an animal model for bladder cancer study.

Primary bladder tumors induced in Fischer 344 inbred rats by N-[4-(5-nitro-2-furyl)-2-thiazolyl]formamide were transplanted in syngeneic rats by the intravesical, s.c., i.v., and orthotopic routes. Attempts were made to establish bladder cancer cell lines in vitro. No success was achieved in transplantation by either the s.c., i.v., or intravesical routes when primary tumor cells were transplanted as cell suspensions. Cell suspensions of primary tumors also failed to grow in culture. However, orthotopic implantation into the bladder submucosa gave 45% success. Tumor fragments obtained from either the primary tumor or its lung metastases resulted in 10.6 and 36% tumor takes, respectively, when implanted s.c. However, after one orthotopic passage in the bladder submucosa, the tumor cells injected as cell suspension grew s.c. in 14% and orthotopically in 79% of the animals. Tumor fragments obtained from orthotopic tumors and implanted s.c. resulted in 15% tumor takes. After the second orthotopic passage, tumor cells could be grown in cultures and orthotopically in 100% of animals. The technique of orthotopic implantation as well as the usefulness of this tumor model for bladder cancer studies are described.