Use of a murine xenograft model for canine transmissible venereal tumor

Objective-To develop a murine model for canine transmissible venereal tumor (CTVT). Animals-Thirty-three 6-week-old NO D/LtSz-scid (NOD/SCID) mice and seven 6- week-old C57BL/6J mice. Procedure-Samples of CTVT were excised from a 3-year-old dog and inoculated SC into ten 6-week-old NOD/SCID mice to induce growth of xenograft transmi ssible venereal tumor (XTVT). To establish mouse-to-mouse transmission, sam ples of XTVT were removed and inoculated SC into 4 groups of 6-week-old NOD /SC[D mice and into a control group. Samples of CTVT were also inoculated i nto immunocompetent C57BL/6J mice for a mouse antibody production (MAP) tes t. The canine and xenografted tumors were evaluated cytologically and histo logically, and polymerase chain reaction was performed for detection of the rearranged LINE/c-MYC junction. Results-8 of 10 NOD/SCID mice that were inoculated with CTVT developed tumo rs 3 to 10 weeks after inoculation. In the second-generation xenograft, all mice developed tumors by postinoculation day 47; 1 X 10(6) of XTVT cells w ere enough to create a xenograft. Metastases developed in 4 of 20 mice. Xen ografted and metastatic tumors retained cytologic, histologic, and molecula r characteristics of CTVT. Results of the MAP test were negative for all pa thogens. Conclusion-We established an NOD/SC[D murine model for XTVT and metastasis of CTVT. This model should facilitate study of tumor transplantation, progr ession, and metastasis and should decrease or eliminate the need for mainta ining allogenic transfer in dogs.