Expression of pleiotrophin and Ki-67 in canine pheochromocytoma: a step forward in the development of prognostic markers

Abstract

In this study we investigated two potential prognostic markers, Ki-67 and pleiotrophin (PTN). We determined the Ki-67 proliferation index using immunohistochemistry and assessed PTN mRNA expression using RT-qPCR in 35 canine PCCs, PTN expression was also determined in 10 normal canine adrenal medullas. With the available antibodies, we were unable to develop a immunohistochemistry protocol to determine PTN protein expression in canine PCCs. PTN expression was significantly higher in PCCs than in the normal adrenal medullas. Higher PTN expression and Ki-67 index were associated with lower cause-related survival. These findings indicate that PTN expression and Ki-67 index are promising prognostic markers in canine PCC. Further research is necessary to validate this and define applicability.