Immunohistochemical expression of heat shock proteins, p63 and androgen receptor in benign prostatic hyperplasia and prostatic carcinoma in the dog

Abstract

This study compared heat shock proteins Hsp60, Hsp72 and Hsp73, along with p63 and androgen receptor (AR) immunoexpression between 16 cases of benign prostatic hyperplasia (BPH) and 11 prostatic carcinomas (PCa) in dogs. The proportion of Hsp60-positive cells was higher in PCa compared with BPH (P = 0.033), whereas the frequency and intensity of Hsp73 immunostaining did not differ significantly between the two groups. Hsp72-immunostained nuclei formed a discontinuous layer along the basement membrane in BPH, whereas cells in this layer in PCa were negative or weakly positive. Hsp72 nuclear score showed significant positive associations with both p63 (P = 0.016) and AR (P = 0.009) scores. Double immunofluorescence revealed Hsp72-p63 and Hsp72-AR co-expressions in basal cell nuclei. Aberrant cytoplasmic p63 immunolabelling was observed in 3 of 11 PCa cases. These results suggest a role of the combined expression of Hsp72, p63 and AR in basal epithelial cells in canine BPH and PCa.

Nectin‐4 and p63 immunohistochemical expression in canine prostate tumourigenesis

“…As far as p63 is concerned, this molecule confirmed its expression pattern in normal and hyperplastic canine prostate, which is typically confined to basal cells, forming a discontinuous layer along the basement membrane, a finding in agreement with the discontinuity of the basal cell layer of canine prostate gland, differently from humans . On the other hand, nuclear p63 immunolabelling was frequently absent or detectable in a low percentage of neoplastic cells in PC cases, confirming that p63+ canine PCs represent a very rare PC subtype .…”

“…Immunohistochemistry was performed using the following primary antibodies (Abs): goat polyclonal anti‐human Nectin‐4 (1:70, AF2659, R&D Systems, Minneapolis, Minnesota) and mouse monoclonal anti‐human p63 (1:400, clone 4A4; DAKO, Glostrup, Denmark), which identifies both p63 isoforms, that is, ΔNp63 and TAp63. Cross‐reactivity with canine tissues for this primary Abs has been previously demonstrated . After deparaffinization and rehydration, antigen retrieval was performed submerging sections in 1 M Urea (pH 8.0) in a microwave for 15 minutes (3 cycles, 5 minutes/each).…”

“…A negative control was performed in all instances by omitting the primary Ab and incubating tissue sections with TBS. The following positive controls were used: canine normal prostate for p63 and canine normal lung for Nectin‐4 …”

“…On the other hand, over‐expression of p63 up‐regulate the expression of cell adhesion molecules, thus increasing cellular adhesion and enhancing CTCs formation and survival . The expression of both p63 isoforms is dysregulated in several human and canine tumours including prostate cancer . In this respect, several studies have investigated p63 expression in canine prostate carcinomas (PCs), revealing that p63+ canine PCs represent a very rare PC group showing a distinct phenotype compared to typical canine PCs .…”

“…17 The expression of both p63 isoforms is dysregulated in several human and canine tumours including prostate cancer. [18][19][20] In this respect, several studies have investigated p63 expression in canine prostate carcinomas (PCs), [19][20][21][22][23] revealing that p63+ canine PCs represent a very rare PC group showing a distinct phenotype compared to typical canine PCs. 20 At the molecular lever, Nectin-4 and p63 are regulated by and regulate Interferon Regulatory Factor 6 (IRF6) protein in differentiated keratinocytes.…”