Fibrosarcoma is a deadly disease in cats and is significantly more 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 transfer in NVS
fibrosarcoma. We isolated and characterized a NVS
fibrosarcoma cell line (Cocca-6A) from a spontaneous
fibrosarcoma that occurred in a domestic calico cat. The feline cells were karyotyped and their chromosome number was counted using a Giemsa staining. 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. Cocca-6A
fibrosarcoma cells were morphologically and cytogenetically characterized. Giemsa block staining of metaphase spreads of the Cocca-6A cells showed deletion of one of the E1 chromosomes, where feline p53 maps. Semi-quantitative PCR demonstrated reduction of p53 genomic
DNA in the Cocca-6A cells. Adenoviral gene transfer determined a remarkable effect on the viability and growth of the Cocca-6A cells following single transduction with adenoviruses carrying Mda-7/IL-24 or IFN-γ or various combination of RB/p105, Ras-DN, IFN-γ, and Mda-7 gene transfer.
Therapy for feline
fibrosarcomas is often insufficient for long lasting
tumor eradication. More gene transfer 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.