Expression of the enzyme indoleamine-2,3-dioxygenase in mammary tumors in dogs

Abstract

On daily small animal veterinary practice throughout the world, mammary cancer is widely recognized as the leading females affecting neoplasia of the canine species. Indoleamine 2,3 - dioxygenase (IDO) is an enzyme expressed by various cells and, among its many functions, works mainly in immune system regulation. This enzyme acts by inhibiting T lymphocytes proliferation by tryptophan catabolism and the production of its metabolite kynurenine. Recent studies in humans and mice have shown that IDO can be used for many cancers as a mechanism for immunological evasion enabling tumor progression since the immune system plays an important role in the response against tumors. Due to its relevance in this context, the high incidence of mammary cancer and the scarce information in the specialized literature, this study aims to characterize the expression of IDO in malignant mammary tumors in dogs; checking for any correlation between the expression of this enzyme and tumor induction and progression. (AU)