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

Abstract

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 ¼ 11) and neoplastic (n ¼ 6 papillomas, n ¼ 11 carcinomas) lesions of the urinary bladder epithelium from rats treated with o-nitroanisole and in normal (n ¼ 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.Keywords cyclin D1, cytokeratin 20, immunohistochemistry, o-nitroanisole, rats, urinary bladder, uroplakin III, urothelial carcinoma Urinary bladder neoplasia is the sixth-most common cancer in humans in the United States, with urothelial carcinoma the most common subtype. 27 The most important risk factors for urinary bladder cancer in the Western world are cigarette smoking, followed by occupational or environmental exposure to aniline and azo dyes and aromatic amines.25 o-Nitroanisole (2-nitroanisole, 2-methoxynitrobenzene) is a single-ring aromatic nitro compound used as an intermediate in the preparation of o-anisidine and the production of azo dyes.22 o-Nitroanisole is reasonably anticipated to be a human carcinogen based on sufficient evidence of malignant tumor formation at multiple tissue sites in multiple species of experimental rodents, including the urinary bladder in rats of both sexes. 22 In the present study, we used immunohistochemistry to characterize the expression patterns of cell cycle-related markers (cyclin D1 and p53) and differentiation markers (cytokeratin 20 [CK20] and uroplakin III [UPIII]) in o-nitroanisole-induced urothelial (transitional cell) hyperplasia and neoplasia in rat urinary bladders to compare with findings ...

Potential plasma biomarkers of bladder cancer identified by proteomic analysis: A pilot study

“…[4][5][6] Moreover, the following molecules that are still under investigation have been reported to be associated with urinary carcinogenesis: BLCA-4, cytokeratin, fibronectin degradation products, uroplakins and their glycovariants, psoriasin, zinc-alpha-2-glycoprotein, pro-matrix metalloproteinase-2 (proMMP-2), matrix metalloproteinase-7 (MMP-7), and endostatin. [7][8][9][10][11][12][13] It has also been reported that the serum levels of CYFRA 21-1 and soluble E-cadherin are associated with advanced and high-grade urothelial bladder carcinoma. 14,15 In the opinion of Goodison et al, most of these biomarkers may be more useful as prognostic factors aiding therapeutic decisions.…”

Urothelial Proliferation of Unknown Malignant Potential Involving the Bladder: Histopathologic Features and Risk of Progression in De Novo Cases and Cases With Prior Neoplasia

“…24 Rat studies with carcinogen induction of bladder neoplasia have also shown a graded increase in urothelial expression of cytokeratin 20, uroplakin III, and nuclear cyclin D1 within the full thickness of the urothelial lining in the context of flat urothelial hyperplasia, although these have not been recommended for routine clinical use in this setting. 25 Given the limited nature of these lesions, studies that maintain tissue architecture in the analysis process and that undertake longitudinal analysis to identify subsequent neoplasia are needed.…”