Effect of Recombinant Feline Interferon-Ω (rFeIFN-Ω) on the Primary CanineTransmissible Venereal Tumor Culture.

Interferons (IFNs), signaling proteins produced by host cells, are secreted in response to pathogen activity as well as to tumor cells, and display antiviral, antiproliferative, and immunomodulatory effects. Recombinant feline interferon omega (rFeIFN-ω) has growth inhibition activities on various canine and feline tumor cell lines. Canine transmissible venereal tumor (CTVT) is used as an animal model for immunotherapy due to its specific growth phase. Previous studies have usually focused on the interaction between tumor infiltrating lymphocytes (TILs) and CTVT cells. However, the specific effects of rFeIFN-ω on CTVT cells remains poorly defined. The aims of this study, therefore, were to evaluate the effect of rFeIFN-ω on primary CTVT cells and to study the mRNA expression of apoptotic genes and drug resistance genes. Purified CTVT cells were treated with various concentrations of rFeIFN-ω and the viability of the cultured cells was ascertained at 24, 48, and 72 h post treatment (hpt) and a dose-response curve plotted. The mRNA expression of apoptotic ( and ) and drug resistance ( and ) genes was performed by reverse transcription quantitative real-time PCR at 72 hpt. rFeIFN-ω displayed an effect against CTVT cell viability, which decreasing viability in a dose-dependent manner within 72 hpt. The relative mRNA expression of was upregulated only at a rFeIFN-ω concentration of 10 IU/100 μl. However, higher concentrations of rFeIFN-ω gave a higher level of relative mRNA expression of transporter gene. This study provided the information of effect of rFeIFN-ω on CTVT cell viability in a dose dependent manner, as well as, the alteration of and gene expression after treatment. These results encourage future studies to evaluate the potential efficacy of this treatment in CTVT cases.