DNA study of bladder papillary tumours chemically induced by N‐butyl‐N‐(4‐hydroxybutyl) nitrosamine in Fisher rats

Abstract

To examine DNA abnormalities in bladder papillary tumours induced by N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN) in female rats, using image cytometric DNA analysis and cytogenetics. Thirty female rats were exposed to BBN in their drinking water for 20 weeks. One group of 10 animals served as controls. The animals exposed to BBN were killed at a rate of two per week, with the bladder being collected under aseptic conditions and those tumours with exophytic growth removed. The nuclear DNA content of the tumours was evaluated using image cytometric analysis. In two rats part of the tumour pieces was stipulated for culturing. Cytogenetic analysis was performed on at least 30 cells from each cell population and on both tumours. Papillary carcinomas were classified as low grade and high grade. DNA ploidy studies were carried out on 28 low-grade and 21 high-grade papillary carcinomas. Histograms obtained by image analysis showed that a normal urothelium was diploid; 28.6% and 100% of low-and high-grade papillary carcinomas were aneuploid respectively. Both tumours used for cell culture showed multiple numerical and structural chromosome alterations and several marker chromosomes. Image cytometric DNA analysis proved to be a good and reliable method for examining DNA alterations in papillary bladder carcinomas. The present findings establish that the DNA content is statistically different between low-grade and high-grade papillary carcinomas and that deviation from the diploid number is markedly higher in the high-grade ones. In addition, the occurrence of marker chromosomes seems to be related to the aggressiveness of the tumour.

DNA cytophotometric and histological analysis of N-butyl-N-(4-hydroxybutyl)nitrosamine-induced precancerous lesions of the bladder urothelium

“…The formal pathogenesis of experimentally induced urinary bladder carcinoma has been differentially described in numerous publications. As in the present work, a 0.05 % N -butyl- N -(4-hydroxybutyl)nitrosamine solution as drinking water in animal studies was frequently the carcinogen used (Akagi et al 1973 ; Arai et al 1974 ; Ito et al 1975 ; Ito 1976 ; Kunze et al 1976 ; Murphy and Irving 1981 ; Fukushima et al 1982 ; Oliveira et al 2005 , 2007 ; Palmeira et al 2009 ; Vasconcelos-Nobrega et al 2012 ). Other researchers have used N -(4-(5-nitro-2-furyl)-2-thiazolyl)formamide (Tiltman and Fridell 1971 ; Cohen et al 1976 ), or N -methyl- N -nitrosourea (Hicks and Chowaniec 1978 ).…”

“…Other researchers have used N -(4-(5-nitro-2-furyl)-2-thiazolyl)formamide (Tiltman and Fridell 1971 ; Cohen et al 1976 ), or N -methyl- N -nitrosourea (Hicks and Chowaniec 1978 ). Focal or multiple hyperplasias of the urothelium were frequently observed first, while disturbances in stratification and maturation appeared in the hyperplasias after longer exposure periods (Ito 1976 ; Kunze et al 1976 ; Murphy and Irving 1981 ; Fukushima et al 1982 ; Oliveira et al 2007 ; Tiltman and Fridell 1971 ; Hicks and Chowaniec 1978 ). These changes were designated as mild, moderate, or severe hyperplasia (Cohen et al 1976 ), dysplasia, or carcinoma in situ (Oliveira et al 2005 , 2007 ).…”

Comparative proteomic analyses of urine from rat urothelial carcinoma chemically induced by exposure to N-butyl-N-(4-hydroxybutyl)-nitrosamine

“…A large scale GeLC-MS/MS strategy was used to analyze the urinary proteome of rats with chemically induced urothelial carcinoma, a well-established animal model of bladder cancer 16 . Indeed, BBN-induced tumors in rats are equivalent to the non-muscleinvasive urothelial carcinoma clinically observed in humans 14,24,25 . Animal models of urothelial carcinoma offer several advantages in medical research 16 as the possibility to follow-up tumors development and relate it with urine proteome dynamics.…”

“…The goal of our study was to characterize urinary protein profile modulated by urothelial carcinoma using GeLC-MS/MS, a strategy that combines one-dimensional SDS-PAGE with reversed phase-HPLC. To fulfill this goal, we utilized an animal model of urothelial carcinogenesis chemically induced by exposure to N-butyl-N- (4-hydroxybutyl)-nitrosamine (BBN), which reflects one of the most commonly occurring malignant tumors of the urinary tract 14,15 . Proteome profiling of urine collected from healthy animals and with urothelial carcinoma (with distinct histological grades) followed by bioinformatic analysis allowed not only the identification of urinary proteins modulated by urothelial carcinoma, but also highlighted the biological…”

Karyometrie BBN-induzierter Präkanzerosen des Urothels

“…Das durch BBN induzierte Spektrum der Neoplasien schien einigen Autoren identisch mit dem der menschlichen Harnblase zu sein [15,18,23]. Wenige Arbeiten legten das Augenmerk auf zytologische Veränderungen des Urothels [8,12,14].…”