Uroplakin expression in the urothelial tumors of cows

Immunohistochemical Expression of Cyclin D1, Cytokeratin 20, and Uroplakin III in Proliferative Urinary Bladder Lesions Induced by o-Nitroanisole in Fischer 344/N Rats

o-Nitroanisole is an intermediate in the manufacture of azo dyes. In a National Toxicology Program stop-exposure study,o-nitroanisole induced hyperplasia, papillomas, and papillary carcinomas in the urinary bladder of Fischer 344/N rats.o-Nitroanisole was investigated since occupational or environmental exposure to aniline and azo dyes is a risk factor for urinary bladder cancer in humans. The current study describes the morphology of urinary bladder neoplasms seen in rats with respect to those observed in humans. This study also evaluated immunohistochemical expression of the cell cycle-related proteins cyclin D1 and p53 and the differentiation markers cytokeratin 20 and uroplakin III in hyperplastic (n= 11) and neoplastic (n= 6 papillomas,n= 11 carcinomas) lesions of the urinary bladder epithelium from rats treated with o-nitroanisole and in normal (n= 6) urinary bladders from untreated rats. The tumors observed were more similar to the papillary type rather than the muscle-invasive type of urinary bladder cancer in humans. The preneoplastic and neoplastic lesions observed suggest progression from hyperplasia to papilloma to papillary carcinoma. With neoplastic progression (hyperplasia to papilloma to carcinoma), cyclin D1 immunoreactivity progressively increased in intensity, percentage of cells staining, and distribution. Overexpression of p53 was not found. Cytokeratin 20 staining decreased in superficial cells, while uroplakin III staining increased in intermediate and basal cells with progression from hyperplasia to carcinoma. The results are consistent with increased cell cycle dysregulation or proliferation (cyclin D1), decreased differentiation (cytokeratin 20), and abnormal differentiation (uroplakin III) as lesions progress toward malignancy.

Epithelial Urinary Bladder Tumors From Cows With Enzootic Hematuria

Thirty-nine epithelial bladder tumor samples from 37 animals affected with bovine enzootic hematuria (BEH) were selected for immunohistochemical studies. The expression of structural proteins such as uroplakin III (UPIII) and cytokeratin 7 (CK7) and the cell cycle–related proteins cyclin D1 and p53 were evaluated in urothelial papillomas and carcinomas. Loss of UPIII and CK7 expression was seen in both high-grade and high-stage urothelial carcinomas ( P < .001 and P < .02). Cyclin D1 expression showed no statistically significant association with grade or stage. In contrast, p53 immunoreactivity was positive in high-grade and high-stage carcinomas ( P < .05 and P < .01), confirming its association with the highest malignant behavior of the bladder tumors in BEH.

Expression of heat shock proteins in premalignant and malignant urothelial lesions of bovine urinary bladder

Abnormal heat shock protein (HSP) levels have been observed in a number of human tumours, where they are involved in all hallmarks of cancer. Since bovine urothelial tumours share striking morphological and biochemical features with their human counterparts, the aim of this study was to evaluate the immunohistochemical levels of Hsp27, Hsp60, Hsp72, Hsp73 and Hsp90 in 28 normal bovine urinary bladders and 30 bovine papillomavirus-positive urothelial tumours (9 in situ carcinomas, 9 low-grade and 12 high-grade carcinomas) and adjacent premalignant lesions obtained from cows suffering from chronic enzootic haematuria, in order to investigate the role of these proteins in the process of urothelial carcinogenesis. A semi-quantitative method was used for the analysis of the results. Western blot analysis was also used to confirm HSP expression in normal controls. All investigated HSPs were expressed in normal bovine urothelium, showing characteristic patterns of immunolabelling throughout urothelial cell layers, which usually appeared to be conserved in urothelial hyperplasia and dysplasia. On the other hand, gradual loss of Hsp27 immunostaining resulted to be significantly associated with increasing histological grade of malignancy (P < 0.01). As well, a significantly reduced immunosignal of Hsp73 and Hsp90 was observed in high-grade and low-/high-grade carcinomas, respectively (P < 0.01). In contrast, Hsp60 (P < 0.01) and Hsp72 (P < 0.05) immunoreactivity appeared to be significantly increased both in premalignant and malignant lesions when compared to that observed in normal urothelium, thus suggesting an early involvement of these proteins in neoplastic transformation of urinary bladder mucosa.

Altered expression of UPIa, UPIb, UPII, and UPIIIa during urothelial carcinogenesis induced by N-butyl-N-(4-hydroxybutyl)nitrosamine in rats

In normal urothelium, superficial umbrella cells express four major integral membrane proteins, uroplakins UPIa, UPIb, UPII, and UPIIIa, which compose urothelial plaques. In the apical plasma membrane, urothelial plaques form microridges. During neoplastic changes, microridges are replaced by microvilli, while uroplakin expression is retained. We correlated individual uroplakin expression with apical plasma membrane structure, cytokeratin 20 expression, and urothelial cell proliferation (Ki-67). Male Wistar rats were treated with 0.05% N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) in drinking water, which caused flat hyperplasia with mild dysplasia, low-grade papillary urothelial carcinoma, invasive low- and high-grade papillary urothelial carcinoma and invasive squamous cell carcinoma with extensive keratinization, grade 2. During urothelial carcinogenesis, UPII expression was the most decreased in all urothelial lesions, while UPIa, UPIb, and UPIIIa expression was differently altered in different types of lesions. Superficial cells were covered with microvilli and ropy ridges, while microridges were disappearing. The expression of cytokeratin 20 was decreased and limited to superficial urothelial cells. Proliferation indices were increased, except for invasive squamous cell carcinoma with extensive keratinization. Our results indicate that during urothelial carcinogenesis the expression of UPII is diminished, suggesting that UPIb/UPIIIa heterodimer can still be formed, while heterodimer UPIa/UPII formation is disrupted. Correlation between decreased level of UPII expression and changed apical plasma membrane structure suggests that diminished expression of UPII hinders the urothelial plaque formation.

Immunohistochemical Evaluation of Vascular Urinary Bladder Tumors from Cows with Enzootic Hematuria

Fifty-six endothelial-derived urinary bladder tumor samples collected from 26 animals with bovine enzootic hematuria were selected for immunohistochemical studies. Expression of factor VHI-related antigen (FVIIIra), CD31, muscle-specific actin, uroplakin III (UPIII), and the cell cycle-related proteins cyclin Dl and p53 was evaluated in hemangiomas, “hemangioendotheliomas” (a vascular tumor that histologically is intermediate in appearance between a hemangioma and a conventional hemangiosarcoma), and hemangiosarcomas. Although CD31 expression was seen in all endothelial tumors tested, FVIIIra was not expressed in poorly differentiated endothelial tumor cells from solid areas or in 7 muscle-invasive hemangiosarcomas. Cyclin Dl overexpression was seen in 53% of hemangiomas, 82% of hemangioendotheliomas, and 95% of hemangiosarcomas. P53 immunoreac-tivity was only seen in muscle-invasive hemangiosarcomas. The UPIII staining pattern, normally very intense on the apical aspect and cytoplasm of superficial urothelial cells, was altered in the urothelium in an estimated 25% of hemangiomas, most hemangioendotheliomas, and most hemangiosarcomas. In conclusion, CD31 is a better marker than FVIIIra in the characterization of bovine endothelial tumors. The cell cycle regulatory pathways involving cyclin Dl and p53 seem to be impaired in endothelial urinary bladder tumors, p53 immunoreactivity positively correlating with enhanced invasion.

Lymphoepithelioma-like carcinoma of the urinary bladder in a cow associated with bovine papillomavirus type-2

Lymphoepithelioma-like carcinoma (LELCA) of the urinary bladder is reported in a 7-year-old cow that had grazed pasture rich in bracken fern and had suffered from severe intermittent haematuria from 3 to 4 years of age. On necropsy examination there were multiple haemorrhagic foci scattered over the mucosal surface of the urinary bladder. Microscopically there were nests, cords and sheets of neoplastic cells infiltrating the lamina propria and muscularis propria. These had a syncytial appearance with ill-defined cytoplasmic borders, large nuclei and prominent nucleoli. There was a prominent associated inflammatory infiltrate comprising lymphocytes and plasma cells with sparse histiocytes and granulocytes. Immunohistochemically, LELCA cells expressed cytokeratin but not vimentin. The LELCA was focally admixed with a concomitant papillary high-grade carcinoma that also infiltrated the lamina propria. A diffuse carcinoma in situ was also present. Bovine papillomavirus type-2 (BPV-2) DNA was amplified from frozen neoplastic tissue and from selected areas of formalin-fixed, paraffin wax-embedded tissue obtained by laser capture microdissection. Microbiological culture of a urine sample resulted in isolation of Weeksella virosa, Rhizobium radiobacter and Staphylococcus warneri. Flow cytometric analysis performed on blood mononuclear cells revealed down-regulation of a panel of markers including CD3, CD4, CD8alpha, CD45, MHC class I and MHC class II (HLA-DRalpha, HLA-DQ, HLA-DP). This report extends the spectrum of neoplastic urothelial lesions described in cattle and provides further evidence that some features of these tumours are similar to human counterparts.

Bovine papillomaviruses, papillomas and cancer in cattle

Bovine papillomaviruses (BPV) are DNA oncogenic viruses inducing hyperplastic benign lesions of both cutaneous and mucosal epithelia in cattle. Ten (BPV 1-10) different viral genotypes have been characterised so far. BPV 1-10 are all strictly species-specific but BPV 1/2 may also infect equids inducing fibroblastic tumours. These benign lesions generally regress but may also occasionally persist, leading to a high risk of evolving into cancer, particularly in the presence of environmental carcinogenic co-factors. Among these, bracken fern is the most extensively studied. The synergism between immunosuppressants and carcinogenic principles from bracken fern and the virus has been experimentally demonstrated for both urinary bladder and alimentary canal cancer in cows whose diets were based on this plant. BPV associated tumours have veterinary and agricultural relevance in their own right, although they have also been studied as a relevant model of Human papillomavirus (HPV). Recent insights into BPV biology have paved the way to new fields of speculation on the role of these viruses in neoplastic transformation of cells other than epithelial ones. This review will briefly summarise BPV genome organization, will describe in greater detail the functions of viral oncoproteins, the interaction between the virus and co-carcinogens in tumour development; relevant aspects of immunity and vaccines will also be discussed.

Sialic Acid and GM3 Ganglioside Expression in Papillomavirus-associated Urinary Bladder Tumours of Cattle with Chronic Enzootic Haematuria

This study was based on 30 papillomavirus-associated urinary bladder tumours from cattle with chronic haematuria, the animals having been kept since birth on pasture rich in bracken fern. The ganglioside content was assessed and compared with that of normal bovine urinary bladders, which was shown to be 28.6+/-3.3 (mean+/-SD) microg of lipid-bound sialic acid per gram of fresh tissue. In neoplastic bladder samples this value was higher but variable (120.9+/-80.6 in benign tumours, and 94.7+/-45.7 in malignant tumours). The main ganglioside, GM3, represented ca 75% of the total ganglioside mixture in normal tissues and 50-80% in tumour samples. GM1, GM2, GD1a, GD3 and FucGM1 were found as minor components. The study suggested that GM3 ganglioside may have a crucial role in "downregulation" of the metastatic potential of bovine urothelial cancers.

Bovine papillomavirus infection in equine sarcoids and in bovine bladder cancers

Bovine papillomavirus (BPV) type 2 is involved in carcinogenesis of the urinary bladder in cattle, while BPV-1 is commonly associated with equine sarcoid tumours. In both cases the early viral proteins are expressed, but virion is not produced. Given the similarities in BPV biology between the tumours in cattle and horses, bovine bladder cancers and equine sarcoids were compared with respect to physical status, load of viral DNA and variability of the E5 open reading frame (ORF). Rolling circle amplification demonstrated that BPV-1 and BPV-2 genomes exist as double stranded, episomal, circular forms in the two tumours. Realtime quantitative PCR revealed that equine sarcoids contained higher viral DNA loads compared to bovine bladder cancers. The BPV-1 E5 ORF showed sequence variation but BPV-2 ORF did not. The presence of BPV-1 E5 variations or their absence in the BPV-2 E5 ORF does not appear to have an effect on viral DNA load in either tumour type.

Bovine papillomavirus type-2 (BPV-2) infection and expression of uroplakin IIIb, a novel urothelial cell marker, in urinary bladder tumors of cows

Several immunohistochemical markers have been used to define the differentiation pattern of urothelial cell tumors of the urinary bladder. We investigated the expression of the recently characterized uroplakin (UP) IIIb, an urothelium-specific and differentiation-dependent protein, in 39 urothelial tumors of the urinary bladder in cows that had suffered from chronic enzootic hematuria for several years. Bovine papillomavirus type 2 DNA was amplified and UP IIIb protein was detected in all these tumors. In papillomas and papillary carcinomas, UP IIIb expression was mostly seen as superficial staining; luminal and peripheral patterns were also observed. In nonpapillary carcinomas, UP IIIb appeared to define clearly the cell membrane lining intercellular and intracellular lumina as well as the cell borders in deeper cell layers. In benign and malignant lesions, an intracytoplasmic immunoreactivity was also detected. Coarse intracytoplasmic UP IIIb-positive material close to the nucleus occurred in some malignant cells. Focally strong membraneous immunostaining that marked single cells with complete ringlike peripheral pattern was seen. Although UP IIIb expression does not seem to correlate with the biological behavior of urothelial tumors, it appears to be a highly sensitive marker for bovine urothelial tumors.

Bovine papillomavirus E5 oncoprotein binds to the activated form of the platelet-derived growth factor beta receptor in naturally occurring bovine urinary bladder tumours

Studies regarding the functions of the bovine papillomavirus (BPV) E5 oncoprotein in vivo are lacking and no E5-mediated mechanism underlying epithelial carcinogenesis is known. We have shown that BPV-2 DNA is present in the majority of naturally occurring urinary bladder tumours of cattle and that E5 is expressed in the cancer cells. Here we show that the interaction between the platelet-derived growth factor (PDGF) beta receptor and BPV E5, described in vitro in cultured cells, takes place in vivo in bovine urinary bladder cancers. In these cancers, E5 and PDGF beta receptor colocalize, as shown by confocal microscopy, and physically interact, as shown by coimmunoprecipitation. Furthermore, the PDGF beta receptor associated with E5 is highly phosphorylated, suggesting the functional activation of the receptor upon E5 interaction. Our results demonstrate, for the first time, that E5-PDGF beta receptor interaction occurs during the natural history of bovine urinary bladder tumours, suggesting an important role for E5 in carcinogenesis. Finally, the system provides a suitable animal model of papillomavirus-associated cancer to test therapeutic vaccination against E5. Successful bladder tumour regression would provide a valuable model for therapeutic vaccination against papillomavirus-associated tumours.

Immunohistochemical detection of uroplakin III, cytokeratin 7, and cytokeratin 20 in canine urothelial tumors

Immunohistochemistry for uroplakin III (UP III), cytokeratin 7 (CK 7), and cytokeratin 20 (CK 20) using commercially available antibodies was done in normal canine urinary bladder and 72 canine urinary bladder tumors that had been fixed in formalin and embedded in paraffin. Prolonged fixation (3-28 days) did not significantly alter the immunostaining for UP III. There was moderate reduction in the intensity for CK 7 and CK 20 after 1 week of fixation. UP III was detected in superficial (umbrella) cells and some intermediate cells of the normal urinary bladder, 7 of 7 transitional cell papillomas (TCPs), 50 of 55 transitional cell carcinomas (TCCs), and 4 of 5 metastatic TCCs. Staining was typically outlined in the plasma membrane, but diffuse or focal cytoplasmic staining was also observed. Intracytoplasmic lumina were usually positive for UP III. One squamous cell carcinoma of the bladder, 4 nonepithelial bladder tumors, and 285 nonurothelial tumors from different nonurinary locations were negative for UP III. CK 7 was detected in 7 of 7 TCPs, 53 of 54 TCCs, and 5 of 5 metastatic TCCs. The staining for CK 7 was diffuse cytoplasmic. CK 20 was detected in 1 of 7 TCPs, 37 of 54 TCCs, and 1 of 5 metastatic TCCs. The staining with CK 20 was cytoplasmic and weaker than with antibodies to UP III or CK 7. There was concurrent expression of UP III, CK 7, and CK 20 in 36 of 54 TCCs. UP III is a specific and sensitive marker for canine transitional epithelial (urothelial) neoplasms, detecting 91% of TCCs. Negative results may be observed with anaplastic tumors.