Gene transfer in a newly established spontaneous feline fibrosarcoma cell line

Fibrosarcoma is a deadly disease in cats and is most often located at classical vaccine injections sites. More rare forms of spontaneous non-vaccination site (NSV) fibrosarcomas have been described and have been found associated to genetic alterations.;Purpose of this study was to compare the efficacy of adenoviral gene therapy in NVS fibrosarcoma. The NVS fibrosarcoma cell line (Cocca-6A) was isolated from a spontaneous fibrosarcoma that occurred in a domestic calico cat. Cocca-6A fibrosarcoma cells were morphologically and cytogenetically characterized. The feline cells were karyotyped and their chromosome number was counted using a Giemsa staining. Giemsa block staining of metaphase spreads of the Cocca-6A cells demonstrated deletion of one of the E1 chromosomes, where feline p53 maps. Adenoviral gene therapy demonstrated a remarkable effect on the viability and growth of the Cocca-6A cells following transduction with adenoviruses carrying RB/p105, Ras-DN, Mda-7/IL-24 or their combination. Adenoviral gene transfer was verified by western blot analysis. Flow cytometry assay and Annexin-V were used to study cell-cycle changes and cell death of transduced cells.;Therapy for feline fibrosarcomas is often insufficient for long lasting tumor eradication. The use of Ad.Ras-DN, Ad.Rb/p105 and Ad.Mda7/IL-24 has been identified as a gene therapy for a possible future adjuvant treatment in spontaneous feline fibrosarcoma. More gene therapy studies should be conducted in order to understand if these viral vectors could be applicable regardless the origin (spontaneous vs. vaccine induced) of feline fibrosarcomas.