Development Of Urinary Bladder Cancer Research Articles

The significance of P53 gene codons 72 and 213 polymorphisms in urinary bladder cancer in Central Poland

Introduction. A major interest in human genetics is to distinguish functionally neutral mutations and polymorphisms from those that contribute to disease. Polymorphic variants of the P53 gene at codon 72 are associated with cancer susceptibility. The aim of our study was to characterize P53 polymorphism at codons 72 and 213 in bladder cancer patients and in a control group. Materials and methods. Ninety-five patients with clinically diagnosed urinary bladder tumors were included in the study. Pathology classified 36 tumors as low grade and 59 as high grade. Tumor stage was pTa or lower in 30 patients and at least pT1 in 65 patients. The control included DNA samples from the blood of 84 cancer-free individuals. The demonstration of codon 72 and codon 213 P53 polymorphisms was performed using PCR and MSSCP techniques. results. In the group of healthy patients we found the following distribution of polymorphism: ARG/ARG – 58.3%, ARG/PRO – 40.5%, and PRO/PRO – 1.2%. In the group of patients suffering from urinary bladder cancer it was 56.8%, 43.2%, and 0.0%, respectively. Statistical analysis of the distributions by the G-test did not reveal any significant difference (table 2x2 G = 0.433) Conclusions. Our study did not reveal that one of the polymorphic variants of the P53 gene codon 72 is a factor increasing the risk of urinary bladder cancer development in the Polish population. It needs to be mentioned, however, that the ARG/ARG genotype (leading to this kind of cancer, according to other researchers) is dominant in the tested population.

Genome-wide association studies in bladder cancer: first results and potential relevance

The role of genetic susceptibility in the development of urinary bladder cancer is unclear, as it is in many other types of cancer. Since 2007, however, an innovative research approach (i.e. genome-wide association studies or GWASs) has led to the identification of numerous genomic loci that harbor susceptibility factors for one or more cancer sites. All GWASs have been published in high-impact journals and the strengths of the design are acknowledged by all experts, but there is criticism about the relevance of the results. Late 2008, the first GWAS in bladder cancer was published. In this review, the principles of GWASs are explained, as well as their strengths and limitations. The study in bladder cancer among 4000 cases and 38,000 controls identified three new susceptibility loci at 8q24, 3q28, and 5p15 that increase the risk of bladder cancer by 22, 19, and 16%, respectively. The results of two other GWASs in bladder cancer are expected to appear this year. Joint analysis of the three studies will probably identify additional susceptibility loci. The results of bladder cancer GWASs may point the way to yet unknown disease mechanisms. So far, the findings are not sufficiently discriminative for risk predictions to be used in clinical care or public health.

Prevention of urinary bladder cancer in the FHIT knock-out mouse with Rofecoxib, a Cox-2 inhibitor

Objectives Aberrant or increased expression of cyclooxygenase-2 (COX-2) has been implicated in the pathogenesis of many diseases, including cancer. However, the exact mechanism by which COX-2 may influence tumorigenesis has yet to be described. To investigate the chemopreventive role of a COX-2 inhibitor, rofecoxib, in the development of urinary bladder cancer, we studied the effect of this drug in heterozygous and nullizygous fragile histidine triad ( FHIT) gene-deficient mice in a chemically induced carcinogenesis model. Materials and methods Two-hundred eight mice consisting of 50 FHIT +/+, 63 FHIT +/– and 95 FHIT –/–, were divided into five treatment groups and followed up for 15 weeks. Mice were treated with freshly prepared solution of 0.1% or 0.01% N-butyl-N-(-4-hydroxybutyl)-nitrosamine (BBN) in their drinking water and rofecoxib was administered in mouse chow at 150 parts per million concentration. Mice were sacrificed, and accurate histological analysis of the bladder was performed. Results Rofecoxib treatment significantly reduced the incidence of preneoplastic lesions/bladder tumors ( P = 0.016). Comparing the incidence of neoplastic lesions in mice treated with rofecoxib and BBN (22/56, 39.3%) and mice treated only with BBN (32/57, 56.1%), a protective role of rofecoxib on the BBN tumor induction has been observed ( P = 0.024). A similar result ( P = 0.002) has been reached observing the incidence of mild and moderate dysplasia in mice treated with a lower concentration of BBN (8/16, 50.0% vs. 20/24, 83.3%).Moreover, as previously observed, a significant increase in neoplastic lesions in the FHIT +/– and FHIT –/– vs. FHIT +/+ mice after BBN treatment has been observed ( P = 0.003). Conclusions These findings suggest that rofecoxib provides a therapeutic defense against bladder carcinogenesis in our model and confirmed that the FHIT knock-out mouse is a suitable system to study in vivo bladder carcinogenesis.

Does RNA editing play a role in the development of urinary bladder cancer?

Purpose A-to-I RNA editing is essential for the development of normal cells and is involved in a wide variety of biological pathways. Currently, limited information suggests linkage between changes in RNA editing levels and the development of cancer. We aimed to explore the possible linkage between altered RNA editing levels and the development of human urinary bladder neoplasms. Materials and methods Thirty-two patients underwent transurethral resection of bladder tumor. Normal and tumoral urinary bladder tissues were obtained from each patient during surgery. Total RNA was extracted from tissue cells and converted by RT-PCR reaction to cDNA molecules for further analysis. We explored known editing sites in RNA encoding for proteins (BLCAP, Cyfip2, FLNA, GluB Q/R) as well as in RNA transcribed from Alu elements in noncoding regions of the genes encoding for CARD11, FANCC, MDM4, BRCA1, and RBBP9 proteins. Editing levels were determined using Sequenom MassARRAY Compact Analyzer. Results Eleven tumoral tissues obtained were low grade TCC, 14 high grade TCC, 1 CIS, and another 5 inflammation. One sample contained only normal tissue. We got a total number of 30 normal bladder tissue samples and overall 29 paired samples (i.e., normal and tumoral tissues obtained from the same patient). Statistical analysis revealed no significant changes in editing levels between normal and tumoral tissues. Conclusions Relying on the results obtained for 9 different editing sites, it can be determined that RNA editing is an epigenetic mechanism that does not participate in the evolution of urinary bladder cancer.

Evaluation of Time Dependence and Interindividual Differences in Benzo[a]pyrene-Mediated CYP1A1 Induction and Genotoxicity in Porcine Urinary Bladder Cell Cultures*

Exposure to tobacco smoke is an established cause of cancer in humans and cigarette smoking is a risk factor for urinary bladder cancer development. Aromatic amines are believed responsible for the bladder-specific carcinogenic effect, but polycyclic aromatic hydrocarbons (PAHs) are also of potential relevance. Urothelial cells contain a number of xenobiotic-metabolizing enzymes, which enable them to convert pro-carcinogens into reactive intermediates. In a preceding study, it was demonstrated using cultured porcine urinary bladder epithelial cells (PUBEC) that CYP1A1 mRNA is induced in a potent manner by treatment with benzo[a]pyrene (BaP). In the present study, the time dependence of these effects was evaluated and whether PUBEC cultures derived from individual donors respond differently to BaP treatment was determined. CYP1A1 induction was analyzed by quantitative reverse-transcription polymerase chain reaction (RT-PCR), and genotoxic effects were studied using the Comet assay. Incubation of PUBEC with BaP increased CYP1A1 expression and induction of DNA strand breaks in a time-dependent manner. Interindividual differences were found between PUBEC cultures derived from several donor animals with respect to the response to BaP, such that the extent of CYP1A1 induction and magnitude of DNA damage was interrelated. Hence, individual differences in metabolic capacities and responsiveness to xenobiotics of urothelial cells from individual donors may be factors in susceptibility to genotoxic effects induced by PAHs.

Gene expression profiling of responses to dimethylarsinic acid in female F344 rat urothelium

Gene expression profiling has been shown to be useful for identifying underlying mechanisms of toxicity, determining patterns of biological response, and elucidating candidate markers of exposure and response. Inorganic arsenic (iAs) is a human carcinogen and epidemiologic evidence implicates it in the development of urinary bladder cancer. Dimethylarsinic acid (DMA), the major excreted metabolite of iAs in humans, is a known rat bladder carcinogen. To examine the changes associated with DMA exposure, microarray analysis of the urothelium was performed in female F344 rats exposed to non-toxic and toxic doses of DMA in their drinking water for 28 days. A novel method for isolating predominantly urothelial cells was developed. Gene expression profiling of the urothelium using a custom 2-dye spotted array revealed that DMA treatment modulated the expression of transcripts of genes that regulate apoptosis, cell cycle regulation and the oxidative stress response. Expression of genes mapping to pathways involved in cancer control processes were also altered after DMA exposure. Morphological data suggested a dose dependent increase in cellular toxicity. Significant changes in differential gene expression were present after all treatments event at doses where standard toxicological responses were not detectable. The greatest perturbation in gene expression was present in rats after treatment with 40 ppm DMA. Doses which produced no histologic or ultrastructural evidence of toxicity (non-toxic) could be differentiated from toxic doses based on the expression of a subset of genes, which control cell signaling and the stress response. These reported changes in gene expression show similarities between the mechanisms of action of DMA in vivo and those previously described for iAs in vitro. These data illustrate the utility of transcriptional profiling and its potential in predicting key mechanistic pathways involved in toxicity and as a time efficient tool to inform the mode of action analysis in risk assessment.

NAT2*5/*5 Genotype (341T>C) Is a Potential Risk Factor for Schistosomiasis-Associated Bladder Cancer in Egyptians

Arylamine N-acetyl transferase (NAT2) displays extensive genetic polymorphisms that affect the rates of acetylation of drugs and genotoxic compounds such as amine carcinogens. To investigate whether the slow acetylator genotype is a risk factor for development of bladder cancer following schistosomal infection of the urinary tract, the authors determined the frequencies of 3 common polymorphisms in the NAT2 gene (341T>C, 590G>A, and 282C>T), which are associated with impaired acetylation activity, in control subjects (n=61; mean age 34.3+/-9.2 years) and in schistosomiasis-associated bladder cancer patients (n=55; 52+/-10.9 years) from the Egyptian population. Genotyping was carried out using rapid cycle PCR on the LightCycler, and subjects were assigned to a slow, intermediate, or rapid acetylator phenotype on the basis of the genotypes. The frequencies of the mutant alleles observed in the controls from the present study were similar to those reported previously for both the Egyptian population and other Arab populations. Patients showed a higher prevalence (78.2%) of slow acetylator phenotype than controls (67.2%), but this did not reach statistical significance (P=0.19). However, there were significantly more individuals who were carriers of 2 mutant 341T>C alleles (NAT2*5/*5 genotype) in the patient group compared with controls (odds ratio 2.6, CI 1.02-6.67, P=0.026). The alloenzyme encoded by this allele has been shown to display a large reduction in its catalytic activity. In conclusion, these data suggest that the NAT2*5/*5 genotype is a potential risk factor for development of urinary bladder cancer in patients with prior schistosomiasis infection.

Inorganic cadmium- and arsenite-induced malignant transformation of human bladder urothelial cells.

Arsenic and cadmium (Cd(+2)) are human carcinogens, and epidemiological studies have implicated both pollutants in the development of urinary bladder cancer. Despite this epidemiological base, it is unknown if either Cd(+2) or arsenite (As(+3)) can directly cause the malignant transformation of human urothelial cells. The goal of this study was to determine if Cd(+2) and/or As(+3) are able to cause the malignant transformation of human urothelial cells. The strategy employed was to expose the nontumorigenic urothelial cell line UROtsa to long-term in vitro exposure to Cd(+2) and As(+3), with the endpoint being the ability of the cells to form colonies in soft agar and tumors when heterotransplanted into nude mice. It was demonstrated that a long-term exposure to either 1 M Cd(+2) or 1 M As(+3) resulted in the selection of cells that were able to form colonies in soft agar and tumors when heterotransplanted into nude mice. The histology of the tumor heterotransplants produced by UROtsa cells malignantly transformed by Cd(+2) had epithelial features consistent with those of a classic transitional-cell carcinoma of the bladder. The histology of the tumor heterotransplants produced by cells malignantly transformed by As(+3) was unique in that the cells displayed a prominent squamoid differentiation.

Detection of carcinogenic aromatic amines in the urine of non-smokers

Smoking is thought to be one of the most important anthropogenic risk factors involved in the development of urinary bladder cancer in humans. Tobacco smoke contains a complex mixture of chemicals including potent carcinogens such as aromatic amines. In the present study the amounts of several freebase aromatic amines including the potent carcinogens 2-aminonaphthalene and 4-aminobiphenyl have been analyzed in the urine of 48 German urban living smokers and non-smokers. The results indicate that (i) both groups excrete the identical set of four aromatic amines; (ii) smokers excrete approximately twice the total amount of these amines, but similar amounts of 2-aminonaphthalene and 4-aminobiphenyl are found in non-smokers; and (iii) the excreted aromatic amines are decomposed in the urine within a few hours thus, explaining why aromatic amines are difficult to detect in this matrix. Their decomposition could be prevented by adding small amounts of p-toluidine to the freshly collected urine. Unlike smokers the origin of aromatic amines detected in the urine of non-smokers is at present unknown. Based on the cotinine levels found in the urine of non-smokers environmental tobacco smoke can be excluded as a major source of aromatic amines. In addition, neither diesel exhaust-related nitroarenes nor the corresponding amino-derivatives, to which they may be metabolically converted, were found. The detected urinary levels of aromatic amines arising from sources other than tobacco smoke or diesel exhaust may play a role in the bladder cancer etiology of non-smokers.

Tumorigenic conversion of a rat urothelial cell line by human polymorphonuclear leukocytes activated by lipopolysaccharide.

Chronic inflammation is a significant risk factor for the development of urinary bladder cancer. We have shown that inflammation induced by killed Escherichia coli and also by its lipopolysaccharide (LPS) strikingly enhances N‐methyl‐N‐nitrosourea (MNU)‐initiated rat bladder carcinogenesis. Aspirates from the bladder lumen contained a large quantity of hydrogen peroxide (H2O2) and several cytokines. In this study, we tested the hypothesis that reactive oxygen intermediates (ROI) released from activated polymorphonuclear leukocytes (PMN) are involved in inflammation‐associated bladder carcinogenesis. Using an immortalized nontumorigenic rat urothelial cell line, MYP3, we examined the effect of LPS‐activated PMN on malignant transformation. MYP3 cells pretreated with or without MNU were exposed daily to LPS‐activated PMN for one week and were then tested for growth in soft agar. In contrast to no colony formation by the parental cells, a varying number of colonies developed from cells treated with LPS‐activated PMN. Although combined treatment with MNU and PMN was most effective (P < 0.01), cells treated with LPS‐activated PMN alone also formed a small number of colonies. Addition of catalase, which decomposes H2O2, and/or an antioxidant, α‐tocopherol, reduced the number of colonies induced by LPS‐activated PMN (P<0.05). Cells derived from colonies were tumorigenic in athymic nude mice. However, tumorigenicity in mice was greater with cells treated with both MNU and PMN than with cells treated with PMN alone. Our results suggest that ROI released from LPS‐activated PMN may be one of the mechanisms involved in the carcinogenesis associated with active urinary tract infection.

Bladder cancers. Their process of development and its modification.

Much information on the development of bladder cancers and its modification has accumulated. It is generally considered that the presence of chemicals in the environment including carcinogens and modifiers (promoters, inhibitors, anti-promoters, etc.) is responsible for the geographical variation in human neoplasia including urinary bladder cancer development. A diagrammatic representation of the possible interactions between environmental factors and tumor development in man is shown in Fig. 6. Thus if potent carcinogens or promoters are present, neoplasia results, with tumor death occurring within an individual's normal lifetime. However, lack of such substances or the existence of powerful inhibitory factors is presumed to slow down the process, so that the normal life-span is not affected. It is therefore of prime importance for thorough awareness of the factors involved to be generated.

Epidemiology and pathogenesis of bladder cancer

First, all known etiologic factors for the development of urinary bladder cancer and those being in discussion are summarized. Consideration is essentially given to industrial carcinogens, tryptophan metabolites, phenacetin, nicotine, coffee, artificial sweeteners, and chronic irritations of the bladder urothelium. In addition, the demographic factors known from the literature, such as familial, geographical, sexual, and racial dispositions are discussed. Another section focuses at the early histological changes of bladder urothelium until tumor manifestation. Especially the significance of the carcinoma in situ is emphasized.