Immunohistochemical expression of survivin in canine cutaneous sebaceous lesions

IntroductionSurvivin is a member of the inhibitor of apoptosis (IAP) protein family and exhibitslow expression in most normal adult tissues. Elevated expression in tissues during embryonicdevelopment and in the majority of cancers, as well as in human sebaceoustumours, indicates potential diagnostic utility. In normal adult human skin, survivinhas been recently proposed as a marker for keratinocyte stem cells.Materials and methods15 canine tumours with sebaceous differentiation (2 carcinomas, 9 adenomas, 1 epithelioma,3 hyperplasia) and 5 specimens of normal canine skin were evaluated histologicallyand immunohistochemically. Full-length survivin (0.7 μg/ml, rabbit polyclonalantibody, NOVUS Biologicals) expression was correlated with p53 (1:400, rabbit polyclonalanti-human antibody, CM1, Novocastra) expression and mitotic index (MI).ResultsSurvivin positive nuclei in normal sebaceous glands were few and scattered. Pre-neoplasticlesions and benign tumours showed several survivin positive nuclei and, apartfrom one case, there was no evidence of p53 expression. Numerous survivin positivenuclei occurred in carcinomas together with a higher mitotic index and large numbersof p53 positive nuclei.DiscussionThe present study revealed for the first time that in dogs, as in human beings, nuclearsurvivin immunohistochemical expression is increased in sebaceous carcinoma cases,compared to normal glands and benign lesions. The findings suggest a direct correlationwith biological behavior, consistent with the anti-apoptotic and proliferative functionsof the molecule.[...]