RESUMEN
BACKGROUND/AIM: Resistant triple-negative breast cancer (TNBC) is a subtype of this disease that is resistant to conventional chemotherapy agents. IFN-τ is a cytokine that has recently been shown to have immunoregulatory and antitumor effects. The present study aimed to examine the antiproliferative and apoptosis effects of IFN-τ in breast cancer cells and the antitumor effect in a murine tumor model of TNBC. MATERIALS AND METHODS: Murine breast cancer 4T1 cells were cultured and treated with ovine IFN-τ and through MTT and Caspase-Glo 3/7 assays, viability and cell death were determined. In addition, the antitumor effect of IFN-τ was determined in a murine tumor model of TNBC. RESULTS: Ovine IFN-τ showed a concentration-dependent antiproliferative effect on 4T1 murine breast cancer cells. Also, treatment of 4T1 cells with IFN-τ induced the activation of caspase 3 and 7, which is indicative of apoptotic cell death. Moreover, we detected an increase in the expression of type I interferon receptor (IFNAR1/2) in cells treated with IFN-. The intratumoral application of IFN-τ in mice inhibited tumor growth compared to the control non-treated group, and the effect was associated with the increased expression of GM-CSF. CONCLUSION: Ovine IFN-τ may be an effective immunotherapeutic cytokine for the treatment of TNBC.