Nanog Expression and Proliferation Indices in Canine Cutaneous Mast Cell Tumors

• Published in: Veterinary pathology Vol. 55; no. 6; pp. 849 - 852
• Main Authors: Joselevitch, Julia A., Barra, Camila N., Vargas, Thiago Henrique M., Pulz, Lidia H., Nishiya, Adriana T., Kleeb, Silvia Regina, Xavier, José Guilherme, Catão-Dias, José Luiz, Strefezzi, Ricardo F.
• Format: Journal Article
• Language: English
• Published: Los Angeles, CA SAGE Publications 01-11-2018
• Subjects: Ki-67; NANOG homeobox protein; mastocytoma; grading; mitotic index; dogs; skin; neoplasm; immunohistochemistry; mast cells; western blot; prognosis
• ISSN: 0300-9858; 1544-2217
• DOI: 10.1177/0300985818789470

Mast cell tumors are one of the most frequent skin tumors in dogs. Treatment decisions often depend on a wide range of clinical information and the main criteria for prognostic formulation are histological grade, mitotic count, Ki67 index, and KIT immunostaining pattern. NANOG is a pluripotency factor expressed by normal and cancer stem cells, which is a prognostic marker and a potential therapeutic target for several human tumors. In the present study, mast cell tumor samples from 41 dogs were evaluated for NANOG and Ki67 by immunohistochemistry. All samples were positive for NANOG but its expression was not correlated with Ki67 index and no significant differences were found with respect to histopathological grades, disease-related mortality, or survival. Our results suggest that, although related to pluripotency, NANOG expression does not correlate with proliferative activity, and is not a reliable prognostic factor for canine cutaneous mast cell tumors.