Canine Prostate Carcinomas Express Markers of Urothelial and Prostatic Differentiation

Abstract

Prostate carcinoma and transitional cell carcinoma (TCC) occur in the prostate gland of older dogs and have morphologic similarities when evaluated by light microscopy. The dog is a commonly used animal model for studying human prostate carcinoma; therefore, it is important to accurately differentiate canine prostate carcinomas from TCCs. We investigated whether keratin 7 (K7) and arginine esterase (AE) would aid differentiation of canine prostate carcinoma from TCC. K7 expression was evaluated in normal and neoplastic canine prostate and bladder tissues using immunohistochemistry. The expression of AE messenger ribonucleic acid (mRNA) in normal and neoplastic canine prostate and bladder was detected using northern blots and reverse transcriptase-polymerase chain reaction (RT-PCR). In addition, AE enzyme activity was measured in normal and neoplastic canine prostate and bladder tissues. We found marked similarities in K7 expression in prostate carcinomas and TCCs. AE mRNA was present in high levels in normal prostatic tissue but was reduced in prostate carcinoma by northern blot assay. Nested RT-PCR detected AE mRNA both in TCCs (13 of 15) and in prostate carcinomas (13 of 13). Enzymatic activity of AE was high in normal prostate gland and in some prostate carcinomas, whereas normal bladder and TCCs produced lower levels of AE. In conclusion, K7 and AE cannot be used to differentiate TCC from prostate carcinoma in dogs.

Regulation of COX‐2 Expression in Canine Prostate Carcinoma: Increased COX‐2 Expression is Not Related to Inflammation

“…The classification of canine PCA into different histologic subtypes and the finding in this study that many tumors consist of more than 1 morphologic tumor subtype confirm the earlier described heterogeneous character of PCA in dogs. 15,26 Two subtypes (micropapillary and solid) clearly dominated, whereas the other subtypes occurred far less frequently.…”

Reproductive System

“…In addition, keratin 7 immunoreactivity and arginine esterase gene expression and enzyme activity do not distinguish canine transitional cell carcinomas from prostate carcinomas-glandular type (LeRoy et al, 2004). Histologically, most canine prostatic carcinomas are of an intraalveolar pattern but many also contain patterns similar to transitional cell carcinoma.…”

Heparin-binding proteins of canine seminal plasma

“…This protein has a molecular weight of 30 kDa and, upon denaturating conditions, it forms two subunits: H and L, 15 and 12-14 kDa, respectively [13,14]. Despite recent advancement in our knowledge of the biochemistry of this constituent [15][16][17], its biological function still remains a matter of speculation.…”