Bladder Carcinogen Research Articles

Dietary sources of N-nitroso compounds and bladder cancer risk: findings from the Los Angeles bladder cancer study.

N-Nitroso compounds (NOCs) have been proposed as possible bladder carcinogens. The main sources of exogenous exposure to NOCs are cigarette smoke and diet, particularly processed (i.e., nitrite-treated) meats. Perhaps more importantly, NOCs can be formed endogenously from dietary precursors such as nitrate, nitrite and amines. Heme has been shown to increase endogenous nitrosation. We examined the role of dietary sources of NOCs and NOC precursors as potential bladder cancer risk factors using data from the Los Angeles Bladder Cancer Study, a population-based case-control study. Dietary and demographic information was collected from 1,660 bladder cancer cases and 1,586 controls via a structured questionnaire. Intake of liver and of salami/pastrami/corned beef, were both statistically significantly associated with risk of bladder cancer in this study, particularly among nonsmokers. Heme intake was also statistically significantly associated with risk of bladder cancer among nonsmokers only. When considering NOC precursors, risk was consistently higher among subjects with concurrent high intake of nitrate and high intake of the different meats (sources of amines and nitrosamines). Results of this study are consistent with a role of dietary sources of NOC precursors from processed meats in bladder cancer risk, suggesting consumption of meats with high amine and heme content such as salami and liver as a risk factor for bladder cancer. In addition, any effect of consuming these meats may be greater when accompanied by high nitrate intake.

A differential mobility spectrometry/mass spectrometry platform for the rapid detection and quantitation of DNA adduct dG‐ABP

There is continued interest in exploring new analytical technologies for the detection and quantitation of DNA adducts, biomarkers which provide direct evidence of exposure and genetic damage in cells. With the goal of reducing clean-up steps and improving sample throughput, a Differential Mobility Spectrometry/Mass Spectrometry (DMS/MS) platform has been introduced for adduct analysis. A DMS/MS platform has been utilized for the analysis of dG-ABP, the deoxyguanosine adduct of the bladder carcinogen 4-aminobiphenyl (4-ABP). After optimization of the DMS parameters, each sample was analyzed in just 30 s following a simple protein precipitation step of the digested DNA. A detection limit of one modification in 10^6 nucleosides has been achieved using only 2 µg of DNA. A brief comparison (quantitative and qualitative) with liquid chromatography/mass spectrometry is also presented highlighting the advantages of using the DMS/MS method as a high-throughput platform. The data presented demonstrate the successful application of a DMS/MS/MS platform for the rapid quantitation of DNA adducts using, as a model analyte, the deoxyguanosine adduct of the bladder carcinogen 4-aminobiphenyl.

Évaluation multicentrique d’un auto-questionnaire de dépistage des cancers de vessie d’origine professionnelle

Evaluate a self-screening questionnaire for bladder cancer of occupational origin and analyse an influence of exposure to a carcinogen bladder tumor on prognosis. Five hundred and thirty-one patients followed, between 2005 and 2010, for bladder cancer in two university centers have received a self-screening questionnaire derived from questionnaire KVP 08. Patients who responded positively to at least one of the items were considered to have a self-screening questionnaire "positive". Patients were finally invited to take an appointment for consultation in occupational pathology. The response rate to self-screening questionnaire was 39.9% (212/531). It was "positive" in 82 cases (38.7%). Among the 82 patients with a self-screening questionnaire "positive", 46 patients consulted in occupational pathology (56%). Occupational exposure to a bladder carcinogen was documented in 91.3% of cases. Among the 22 patients who consulted in occupational pathology with a self-screening questionnaire "negative", an occupational exposure to a bladder carcinogen was documented in 13.6% of cases. The sensibility of the self-screening questionnaire was 91.3%, the specificity 86.4% and the accuracy 89.7%. The relative risk to have an occupational exposure if the self-screening questionnaire was "positive" was 6.69. The analysis of groups "positive" versus "negative" does not reveal any statistically significant difference in terms of tumor aggressiveness and disease-free survival. The self-screening questionnaire was considered relevant with good reliability for detection of occupational exposure to a bladder carcinogen.

Cadmium in blood of Tunisian men and risk of bladder cancer: interactions with arsenic exposure and smoking

Prior investigations identified an association between low-level blood arsenic (As) and bladder cancer risk among Tunisian men but questions remain regarding confounding by cadmium (Cd), a well-established bladder carcinogen. A case-control study of Tunisian men was re-examined to assess the levels of cadmium in blood and reparse the association between the simultaneous exposure to these metals and bladder cancer risk. Levels of blood Cd were significantly twice higher among cases than in controls (P<0.05) and were positively correlated with smoking and age. Additionally, analysis of metal levels among non-smokers according to the region of residence showed very high blood Cd and As levels for the coastal regions of Sfax and central Tunisia. After controlling for potential confounders, for low blood As levels (<0.67 μg/L), the OR for blood Cd was 4.10 (95 % CI 1.64-10.81), while for higher levels (>0.67 μg/L), it was reduced to 2.10 (CI, 1.06-4.17). Adjustment for Cd exposure did not alter the risk associated to As exposure. This study is the first to report the relationship between Cd exposure and risk of bladder cancer occurrence in interaction with smoking and As exposure. Smoking is shown to be the main exposure source to Cd in the Tunisian population but also environmental pollution seems to be responsible of Cd exposure among non-smokers. Exposure assessment studies encompassing a wider population are needed.

Elevated 4-aminobiphenyl and 2,6-dimethylaniline hemoglobin adducts and increased risk of bladder cancer among lifelong nonsmokers--The Shanghai Bladder Cancer Study.

4-Aminobiphenyl (ABP) is an established human bladder carcinogen, with tobacco smoke being a major source of human exposure. Other arylamine compounds, including 2,6-dimethylaniline (2,6-DMA), have been implicated as possible human bladder carcinogens. Hemoglobin adducts of 4-ABP and 2,6-DMA are validated biomarkers of exposure to those compounds in humans. The Shanghai Bladder Cancer Study enrolled 581 incident bladder cancer cases and 604 population controls. Each participant was solicited for his/her history of tobacco use and other lifestyle factors and donation of blood and urine specimens. Red blood cell lysates were used to quantify both hemoglobin adducts of 4-ABP and 2,6-DMA. Urine samples were used to quantify total cotinine. ORs and 95% confidence intervals (CI) for bladder cancer were estimated using unconditional logistic regression methods. Among lifelong nonsmokers, ORs (95% CIs) of bladder cancer for low (below median of positive values) and high versus undetectable levels of 2,6-DMA hemoglobin adducts were 3.87 (1.39-10.75) and 6.90 (3.17-15.02), respectively (Ptrend < 0.001). Similarly, among lifelong nonsmokers, ORs (95% CIs) of bladder cancer for third and fourth versus first/second quartiles of 4-ABP hemoglobin adducts was 1.30 (0.76-2.22) and 2.29 (1.23-4.24), respectively (Ptrend = 0.009). The two associations were independent of each other. Hemoglobin adducts of 4-ABP and 2,6-DMA were significantly and independently associated with increased bladder cancer risk among lifelong nonsmokers in Shanghai, China. The findings of the present study in China with previous data in Los Angeles, California strongly implicate arylamines as potential causal agents of human bladder cancer.

Benzo[a]pyrene-mediated toxicity in primary pig bladder epithelial cells: A proteomic approach

The studies described in this paper deal with a sequence of cellular events induced by the environmental toxicant benzo[a]pyrene (B[a]P) that were investigated in primary urinary bladder epithelia cells (PUBEC) from pigs by using a proteomic approach. Two-dimensional (2DE) gel electrophoresis unveiled the differences in protein expression between cells exposed to 0.5 μM B[a]P for 24 h and control cells. Twenty-five differentially expressed proteins involved in DNA repair, mitochondrial dysfunction, and apoptosis were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). These findings were supported by the concentration-dependent increase in olive tail moments as determined by the comet assay and by a time-dependent increase in histone H2A.x (H2AX) phosphorylation upon B[a]P exposure. On the other hand, the expression of voltage-dependent anion channel 2 (VDAC2), cathepsin D (CTSD), heat shock protein 27 (HSP27), and heat shock protein 70 (HSP70) hinted to apoptosis occurring through the intrinsic apoptotic mitochondrial pathway. Taken together, these data suggest that B[a]P is capable of inducing DNA damage in urinary bladder epithelial cells at low concentrations during a short exposure period, thus eventually leading to cell death by apoptosis. Epidemiological studies have indicated PAHs as potential candidates for initiating bladder cancer development, although the precise risk is still unknown (Kaufman et al. (2009)). In recent years, the understanding of the metabolic capacity of urothelial cells has broadened continuously; i.e. a wide range of xenobiotic metabolizing cytochrome P450 enzymes (CYP) were detected in urothelial cells from humans and animals (Roos et al., 2006; Guhe et al., 1996), thus indicating that urothelial cells are not only passively exposed to reactive metabolites but also actively by intracellularly producing reactive intermediates that can induce cancer. Moreover, small quantities of non-metabolized B[a]P and its hydroxylated derivatives have been identified in blood and urine (Rossella et al. (2009)). Thus, it appears plausible that B[a]P, a highly lipophilic compound, is taken up by the urothelium and metabolically activated to carcinogenic intermediates in these cells. In our previous studies with primary uroepithelial cells isolated from freshly slaughtered pigs we demonstrated the ability of these cells for a strong uptake of B[a]P and its conversion to the oxidative metabolite (3-OH-B[a]P) (Verma et al. (2012)). The present study is a continuation of this previous work exhibiting the effects of B[a]P exposure on cellular functions of PUBEC. The results indicated caspase-dependent apoptosis induced by B[a]P due to DNA damage (possibly lethal double-strand breaks as indicated by H2AX phosphorylation). Taken together, these studies provide strong evidence for the ability of B[a]P to act as a bladder carcinogen.

Abstract 310: Role of AMPKalpha isoforms in bladder tumorigenesis.

Abstract Bladder cancer is the fifth most diagnosed cancer and currently is one of the most expensive cancers to treat due to lifelong surveillance. Bladder cancer is marked by two distinct pathways that result in either noninvasive low grade or invasive high grade cancer. Although low and high grade bladder cancers are defined by driver mutations, similarities such as mTORC1 pathway activation exist. Along these lines rapamycin treatment, an mTORC1 inhibitor, has been shown to suppress tumorigenesis in a mouse model of bladder cancer. These data suggest that mTORC1 activation may be an early tumorigenic event in the bladder. In order to elucidate the mechanism by which the mTORC1 signaling is increased, AMPK (AMP-activated protein kinase), a critical negative regulator of the pathway, was further investigated. AMPK governs a cell's response to metabolic stressors by suppressing anabolic pathways and inhibiting cell growth. Furthermore, it has been observed that AMPK activation is diminished in primary breast cancer. In order to determine whether AMPK activation and/or levels are altered in bladder cancer, a pilot cohort of human samples was obtained and the expression of both AMPKa catalytic isoforms was assessed. Both AMPKa1 and AMPKa2 were significantly suppressed in bladder cancer. AMPKa isoform levels in adjacent non-tumor bladder epithelium and bladder cancer were evaluated in matched patient samples and this revealed cancer-specific AMPKa suppression does indeed exist. Additionally, AMPKa1 protein levels were partially suppressed in low grade cancer and further suppressed in high grade cancer. In contrast, AMPKa2 levels were uniformly suppressed in both high and low grade of cancer. Interestingly, it was observed that AMPKa1 is localized predominantly to the cytoplasm while AMPKa2 was present in cytoplasmic and nuclear compartments. This data suggests that the AMPKa isoforms may have distinct roles in the bladder. To test whether loss of AMPKa2 function promoted bladder tumorigenesis, wild-type and AMPKa2-/- mice received 0.05% BBN [n-butyl-n-(4 hydroxybutyl)] nitrosamine, a rodent bladder carcinogen, in drinking water over the course of 20 weeks. Significant tumors were observed at 20 weeks in both wild-type and AMPKa2-/- mice and bladder weights were significantly higher in AMPKa2-/- mice correlating with larger bladder tumor mass. Additionally, there was a significant increase in the amount of proliferating tumor cells as assessed by Ki67 in the AMPKa2-/- mice. This study suggests that AMPKa isoforms are suppressed in bladder cancer and that AMPKa may play a critical role in bladder cancer progression by loss of expression and tumor suppressive function. Citation Format: Stavros Kopsiaftis, Kathryn N. Phoenix, Katie L. Sullivan, Poornima Hegde, John A. Taylor, Kevin P. Claffey. Role of AMPKalpha isoforms in bladder tumorigenesis. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 310. doi:10.1158/1538-7445.AM2013-310

1127 QUANTIFICATION OF MAJOR BLADDER CARCINOGENS - ACROLEIN AND AMINOBIPHENYL-INDUCED DNA ADDUCTS IN NORMAL HUMAN UROTHELIAL MUCOSA AND BLADDER TUMOR TISSUE

You have accessJournal of UrologyBladder Cancer: Basic Research (III)1 Apr 20131127 QUANTIFICATION OF MAJOR BLADDER CARCINOGENS - ACROLEIN AND AMINOBIPHENYL-INDUCED DNA ADDUCTS IN NORMAL HUMAN UROTHELIAL MUCOSA AND BLADDER TUMOR TISSUE Hyun-Wook Lee, Hsiang-Tsui Wang, Mao-wen Weng, Yan Liu, William C. Huang, Nicholas Donin, Xue-Ru Wu, Herbert Lepor, and Moon-shong Tang Hyun-Wook LeeHyun-Wook Lee New York, NY More articles by this author , Hsiang-Tsui WangHsiang-Tsui Wang New York, NY More articles by this author , Mao-wen WengMao-wen Weng New York, NY More articles by this author , Yan LiuYan Liu New York, NY More articles by this author , William C. HuangWilliam C. Huang New York, NY More articles by this author , Nicholas DoninNicholas Donin New York, NY More articles by this author , Xue-Ru WuXue-Ru Wu New York, NY More articles by this author , Herbert LeporHerbert Lepor New York, NY More articles by this author , and Moon-shong TangMoon-shong Tang New York, NY More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2013.02.742AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Tobacco smoke (TS) is the major cause of bladder cancer (BC) in the US; BC incidence in tobacco smokers is 5-fold higher than in nonsmokers. TS contains 2 chemicals, 4-hydroxy-aminobiphenyl (ABP) and acrolein (Acr) that cause BC in animal models. Since ABP is a major cause of occupation-related BC and ABP-DNA adducts have been found in human bladder tissue, it has long been suspected that ABP is a major human bladder carcinogen in TS. While the amount of ABP in TS is minute (<5 ng/cigarette), the amount of Acr in TS is more than 100,000-fold higher than ABP. Moreover, Acr can form Acr-deoxyguanosine (Acr-dG) adducts that are mutagenic and can inhibit DNA repair and enhance DNA damage-induced mutations. Since inhaled Acr is excreted in urine, we hypothesize that Acr may initiate bladder carcinogenesis. As a first step to test this hypothesis we quantify Acr and ABP induced DNA adducts in normal human urothelium and in BC tissues. METHODS We developed 2 methods for quantification of Acr-dG and ABP-DNA adducts in human bladder tissues: 1) chemistry method using 32P post-labeling the adducted nucleotides followed by 2- and 4-dimensional thin layer chromatography and high performance liquid chromatography, and 2) immunochemical method using monoclonal antibody against Acr-dG adducts as first antibody and labeling the second antibody with quantum dot. We determined the levels of Acr-dG and ABP-DNA adducts in 20 normal human urothelial mucosa samples and in 10 BC samples. RESULTS Both methods can quantify Acr-dG and ABP-DNA adduct levels and yield comparable results. The immunochemical method is 40-fold more sensitive than the chemistry method. Acr-dG adduct levels are 20-100-fold higher than ABP-DNA adduct levels in both normal urothelium and BC tissues, and Acr-dG levels in BC tissues are 2-fold higher than in normal urothelium. CONCLUSIONS The levels of Acr-DNA adducts in normal human urothelium are 20-100 times higher than ABP-DNA adduct levels, and Acr-dG levels in BC tissues are 2 times higher than in normal urothelium. These results support the hypothesis that Acr is a major bladder carcinogen, and will have a major impact on bladder cancer risk assessment and design of new BC prevention strategies. © 2013 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 189Issue 4SApril 2013Page: e460-e461 Advertisement Copyright & Permissions© 2013 by American Urological Association Education and Research, Inc.MetricsAuthor Information Hyun-Wook Lee New York, NY More articles by this author Hsiang-Tsui Wang New York, NY More articles by this author Mao-wen Weng New York, NY More articles by this author Yan Liu New York, NY More articles by this author William C. Huang New York, NY More articles by this author Nicholas Donin New York, NY More articles by this author Xue-Ru Wu New York, NY More articles by this author Herbert Lepor New York, NY More articles by this author Moon-shong Tang New York, NY More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Decreased Tumorigenesis and Mortality from Bladder Cancer in Mice Lacking Urothelial Androgen Receptor

Much fewer mice lacking androgen receptor (AR) in the entire body develop bladder cancer (BCa). However, the role of urothelial AR (Uro-AR) in BCa development remains unclear. In the present study, we generated mice that lacked only Uro-AR (Uro-AR(-/y)) to develop BCa by using the carcinogen BBN [N-butyl-N-(4-hydroxybutyl)-nitrosamine] and found that Uro-AR(-/y) mice had a lower incidence of BCa and a higher survival rate than did their wild-type (WT; Uro-AR(+/y)) littermates. In vitro assay also demonstrated that Uro-AR facilitates the neoplastic transformation of normal urothelial cells to carcinoma. IHC staining exhibited less DNA damage, with much higher expression of p53 and its downstream target protein PNCA in Uro-AR(-/y) than that found in WT urothelium, which suggests that Uro-AR may modulate bladder tumorigenesis through p53-PCNA DNA repair signaling. Indeed, Uro-AR(-/y) mice with the transgene, simian vacuolating virus 40 T (SV40T), in the urothelium (Uro-SV40T-AR(-/y)) had a similar incidence of BCa as did their WT littermates (Uro-SV40T-AR(+/y)), and p53 was inactivated by SV40T in both genotypes. Use of the AR degradation enhancer ASC-J9 led to suppression of bladder tumorigenesis, with few adverse effects in the BBN-induced BCa mouse model. Together, these results provide the first direct in vivo evidence that Uro-AR has an important role in promoting bladder tumorigenesis and BCa progression. Targeting AR with ASC-J9 may provide a novel approach to suppress BCa initiation.

Genotoxicity of tobacco smoke‐derived aromatic amines and bladder cancer: current state of knowledge and future research directions

Bladder cancer is a significant public health problem, worldwide. In the United States, bladder cancer is the fourth most common cancer in men, and its recurrence rate is the highest among all malignancies. Tobacco smoking is the leading risk factor for bladder cancer. The risk of bladder cancer is directly related to the intensity and duration of smoking, while quitting smoking reduces this risk. The increased risk of smokers for developing bladder cancer is attributable to their exposure to aromatic amines, which constitute a family of known bladder carcinogens present in tobacco smoke. The underlying mechanism of action of aromatic amines in the genesis of bladder cancer is not, however, fully delineated. Research has identified a genotoxic mode of action, specifically DNA adduction and mutagenicity, for aromatic amines, which may account for their carcinogenicity. The present review summarizes our current knowledge on the DNA adduction and mutagenicity of aromatic amines in relation to smoking-associated bladder cancer. For illustrative purposes, representative results from published research on aromatic amine-induced DNA adduction and mutagenesis are discussed. The direction of future research on the underlying mechanisms of tobacco smoke-associated bladder carcinogenesis is also outlined. Understanding the molecular mechanisms of bladder carcinogenesis is essential for improving future strategies for prevention, early detection, treatment, and prognosis of this malignancy.

Effect of dietary treatment with dimethylarsinous acid (DMAIII) on the urinary bladder epithelium of arsenic (+3 oxidation state) methyltransferase (As3mt) knockout and C57BL/6 wild type female mice

Chronic exposure to inorganic arsenic (iAs) is carcinogenic to the human urinary bladder. It produces urothelial cytotoxicity and proliferation in rats and mice. DMAV, a major methylated urinary metabolite of iAs, is a rat bladder carcinogen, but without effects on the mouse urothelium. DMAIII was shown to be the likely urinary metabolite of DMAV inducing urothelial changes and is also postulated to be one of the active metabolites of iAs. To evaluate potential DMAIII-induced urothelial effects, it was administered to As3mt knockout mice which cannot methylate arsenicals. Female C57BL/6 wild type and As3mt knockout mice (10/group) were administered DMAIII, 77.3ppm in water for four weeks. Urothelial effects were evaluated by light and scanning electron microscopy (EM) and immunohistochemical detection of bromodeoxyuridine (BrdU) incorporation. EM findings were rated 1–5, with higher rating indicating greater extent of cytotoxicity visualized. DMAIII significantly increased the BrdU labeling index, a ratio of BrdU labeled cells to non-labeled cells, in the treated knockout group compared to control and wild type treated groups. DMAIII induced simple hyperplasia in more knockout mice (4/10) compared to wild type mice (2/10). All treated knockout mice had more and larger intracytoplasmic granules compared to the treated wild type mice. Changes in EM classification were not significant. In conclusion, DMAIII induces urothelial toxicity and regenerative hyperplasia in mice and most likely plays a role in inorganic arsenic-induced urothelial changes. However, DMAV does not induce hyperplasia in mice, suggesting that urinary concentrations of DMAIII do not reach cytotoxic levels in DMAV-treated mice.

Understanding the Gender Disparity in Bladder Cancer Risk: The Impact of Sex Hormones and Liver on Bladder Susceptibility to Carcinogens

It has long been known that bladder cancer (BC) incidence is approximately four-fold higher in men than in women in the United States, and a similar disparity also exists in other countries. The reason for this phenomenon is not known, which impedes progress in BC prevention. However, BC incidence is also significantly higher in male animals than in their female counterparts after treatment with aromatic amines, which are principal human bladder carcinogens. These animal studies and related studies in the context of available human data provide significant insight into what may drive the excessive BC risk in men, which is the focus of this article. The carcinogenicity and biotransformation of bladder carcinogens as well as the impact of sex hormones on these processes are discussed, highlighting the novel concept that the gender disparity in BC risk may result primarily from the interplay of androgen, estrogen, and liver, with the liver functioning via its metabolic enzymes as the main decider of bladder exposure to carcinogens in the urine and the male and female hormones exerting opposing effects on carcinogenesis in the bladder and likely also on liver enzymes handling bladder carcinogens. The findings may facilitate further investigation into the mechanism of gender disparity in BC risk and may also have important implications for BC prevention.

Distinct SNP Combinations Confer Susceptibility to Urinary Bladder Cancer in Smokers and Non-Smokers

Recently, genome-wide association studies have identified and validated genetic variations associated with urinary bladder cancer (UBC). However, it is still unknown whether the high-risk alleles of several SNPs interact with one another, leading to an even higher disease risk. Additionally, there is no information available on how the UBC risk due to these SNPs compare to the risk of cigarette smoking and to occupational exposure to urinary bladder carcinogens, and whether the same or different SNP combinations are relevant in smokers and non-smokers. To address these questions, we analyzed the genotypes of six SNPs, previously found to be associated with UBC, together with the GSTM1 deletion, in 1,595 UBC cases and 1,760 controls, stratified for smoking habits. We identified the strongest interactions of different orders and tested the stability of their effect by bootstrapping. We found that different SNP combinations were relevant in smokers and non-smokers. In smokers, polymorphisms involved in detoxification of cigarette smoke carcinogens were most relevant (GSTM1, rs11892031), in contrast to those in non-smokers with MYC and APOBEC3A near polymorphisms (rs9642880, rs1014971) being the most influential. Stable combinations of up to three high-risk alleles resulted in higher odds ratios (OR) than the individual SNPs, although the interaction effect was less than additive. The highest stable combination effects resulted in an OR of about 2.0, which is still lower than the ORs of cigarette smoking (here, current smokers' OR: 3.28) and comparable to occupational carcinogen exposure risks which, depending on the workplace, show mostly ORs up to 2.0.

Evaluation of gene expression changes in human primary uroepithelial cells following 24‐Hr exposures to inorganic arsenic and its methylated metabolites

Gene expression changes in primary human uroepithelial cells exposed to arsenite and its methylated metabolites were evaluated to identify cell signaling pathway perturbations potentially associated with bladder carcinogenicity. Cells were treated with mixtures of inorganic arsenic and its pentavalent or trivalent metabolites for 24 hr at total arsenic concentrations ranging from 0.06 μM to 18 μM. One series (five samples) was conducted with arsenite and pentavalent metabolites and a second (10 samples) with arsenite and trivalent metabolites. Similar gene expression responses were obtained for pentavalent or trivalent metabolites. A suite of eight gene changes was consistently identified across individuals that reflect effects on key signaling pathways: oxidative stress, protein folding, growth regulation, metallothionine regulation, DNA damage sensing, thioredoxin regulation, and immune response. No statistical significance of trend (NOSTASOT) analysis of these common genes identified lowest observed effect levels (LOELs) from 0.6 to 6.0 μM total arsenic and no observed effect levels (NOELs) from 0.18 to 1.8 μM total arsenic. For the trivalent arsenical mixture, benchmark doses (BMDs) ranged from 0.13 to 0.92 μM total arsenic; benchmark dose lower 95% confidence limits (BMDLs) ranged from 0.09 to 0.58 μM total arsenic. BMDs ranged from 0.53 to 2.7 μM and BMDLs from 0.35 to 1.7 μM for the pentavalent arsenical mixture. Both endpoints varied by a factor of 3 across individuals. Thisstudy is the first to examine gene expression response in primary uroepithelial cells from multiple individuals and to identify no effect levels for arsenical-induced cell signaling perturbations in normal human cells exposed to a biologically plausible concentration range.

Rs11892031[A] on chromosome 2q37 in an intronic region of the UGT1A locus is associated with urinary bladder cancer risk

Recently, rs11892031[A] has been identified in a genome-wide association study (GWAS) to confer increased risk of urinary bladder cancer (UBC). To confirm this association and additionally study a possible relevance of exposure to urinary bladder carcinogens, we investigated the IfADo UBC study group, consisting of eight case-control series from different regions including 1,805 cases and 2,141 controls. This analysis was supplemented by a meta-analysis of all published data, including 13,395 cases and 54,876 controls. Rs11892031 A/A was significantly associated with UBC risk in the IfADo case-control series adjusted to cigarette smoking, gender, age and ethnicity (OR = 1.18; 95% CI = 1.02-1.37; P = 0.026). In the meta-analysis, a convincing association with UBC risk was obtained (OR = 1.19; 95% Cl = 1.12-1.26; P < 0.0001). Interestingly, the highest odds ratios were obtained for individual case-control series with a high degree of occupational exposure to polycyclic aromatic hydrocarbons and aromatic amines: cases with suspected occupational UBC (OR = 1.41) and cases from the highly industrialized Ruhr area (OR = 1.98) compared with Ruhr area controls (all combined OR = 1.46). Odds ratios were lower for study groups with no or a lower degree of occupational exposure to bladder carcinogens, such as the Hungary (OR = 1.02) or the ongoing West German case-control series (OR = 1.06). However, the possible association of rs11892031[A] with exposure to bladder carcinogens still should be interpreted with caution, because in contrast to the differences between the individual study groups, interview-based data on occupational exposure were not significantly associated with rs11892031. In conclusion, the association of rs11892031[A] with UBC risk could be confirmed in independent study groups.

74 OCCUPATIONAL RISK FOR INITIAL BLADDER CANCER DIAGNOSIS IN BRAZIL

You have accessJournal of UrologyGeneral & Epidemiological Trends & Socioeconomics: Evidence-based Medicine & Outcomes II1 Apr 201274 OCCUPATIONAL RISK FOR INITIAL BLADDER CANCER DIAGNOSIS IN BRAZIL Sanarelly Adonias, Daher C. Chade, Alexandre C. Sant'Anna, Sabrina T. Reis, Daniel K. Abe, Flavio G.M. Areas, T.T. Suzaki, Katia R. Leite, Miguel Srougi, and Marcos F. Dall'Oglio Sanarelly AdoniasSanarelly Adonias Sao Paulo, Brazil More articles by this author , Daher C. ChadeDaher C. Chade Sao Paulo, Brazil More articles by this author , Alexandre C. Sant'AnnaAlexandre C. Sant'Anna Sao Paulo, Brazil More articles by this author , Sabrina T. ReisSabrina T. Reis Sao Paulo, Brazil More articles by this author , Daniel K. AbeDaniel K. Abe Sao Paulo, Brazil More articles by this author , Flavio G.M. AreasFlavio G.M. Areas Sao Paulo, Brazil More articles by this author , T.T. SuzakiT.T. Suzaki Sao Paulo, Brazil More articles by this author , Katia R. LeiteKatia R. Leite Sao Paulo, Brazil More articles by this author , Miguel SrougiMiguel Srougi Sao Paulo, Brazil More articles by this author , and Marcos F. Dall'OglioMarcos F. Dall'Oglio Sao Paulo, Brazil More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2012.02.120AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Although bladder cancer risk factors are well known, it is not clear what is the actual impact of daily occupation on current series. Smoking represents the main preventable risk variable, with almost 45% of cases associated. Occupational hazards is estimated to be related to bladder cancer development in 5% to 25% of patients, with wide variation of findings among different studies. We sought to analyze the impact of occupational risk, comparing patients with bladder cancer according to their professional activitiy and its association to symptoms, stage and oncologic outcomes. METHODS We included 100 patients with bladder cancer after transurethral resection between 2008 and 2011. 64% were male. We analyzed presenting symptoms, stage, grade, and number of lesions. A questionnaire regarding current and past profession, years of work and daily habits were applied in all patients. Patients included in group 1 were those with no professions previously related to bladder cancer risk. Group 2 represented patients at risk due to professions or activities that exposes workers to chemicals known as bladder carcinogens, such as in rubber and chemical industries. Statistical analysis was performed using chi-square and Fisher tests with SPSS v13. RESULTS Patients in group 2 presented significantly higher incidence of disuria as a presenting symptom (p=0.001). Patients in group 2 had a higher incidence of T1 disease at diagnosis (36% vs 18%), although not statistically significant (p=0.059). There was no difference among other variables between groups 1 and 2, such as rate of recurrence (21% vs 22%), 3 or more lesions (22% vs 19%), or grade. Also, other presenting symptoms (hematuria, urinary retention, frequency and urgency) had similar rates between the two groups. CONCLUSIONS Irritative urinary symptoms are more frequently encountered among patients with bladder cancer who are exposed to bladder carcinogens due to professional activities than with no occupational risks. Therefore, presenting symptoms may help in the initial bladder cancer diagnosis in patients with a history of occupational exposure. © 2012 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 187Issue 4SApril 2012Page: e31-e32 Advertisement Copyright & Permissions© 2012 by American Urological Association Education and Research, Inc.MetricsAuthor Information Sanarelly Adonias Sao Paulo, Brazil More articles by this author Daher C. Chade Sao Paulo, Brazil More articles by this author Alexandre C. Sant'Anna Sao Paulo, Brazil More articles by this author Sabrina T. Reis Sao Paulo, Brazil More articles by this author Daniel K. Abe Sao Paulo, Brazil More articles by this author Flavio G.M. Areas Sao Paulo, Brazil More articles by this author T.T. Suzaki Sao Paulo, Brazil More articles by this author Katia R. Leite Sao Paulo, Brazil More articles by this author Miguel Srougi Sao Paulo, Brazil More articles by this author Marcos F. Dall'Oglio Sao Paulo, Brazil More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

1069 ABERRATION OF A CELL ADHESION MOLECULE, CADM1, AND ITS PATHOLOGICAL OR BIOLOGICAL SIGNIFICANCE IN URINARY BLADDER CANCER

You have accessJournal of UrologyBladder Cancer: Basic Research III1 Apr 20121069 ABERRATION OF A CELL ADHESION MOLECULE, CADM1, AND ITS PATHOLOGICAL OR BIOLOGICAL SIGNIFICANCE IN URINARY BLADDER CANCER Taketo Kawai, Akiteru Goto, Masayoshi Nagata, Miwako Iwai, Teppei Morikawa, Shigeki Morita, Haruki Kume, Masashi Fukayama, Yukio Homma, and Yoshinori Murakami Taketo KawaiTaketo Kawai Tokyo, Japan More articles by this author , Akiteru GotoAkiteru Goto Akita, Japan More articles by this author , Masayoshi NagataMasayoshi Nagata Tokyo, Japan More articles by this author , Miwako IwaiMiwako Iwai Tokyo, Japan More articles by this author , Teppei MorikawaTeppei Morikawa Tokyo, Japan More articles by this author , Shigeki MoritaShigeki Morita Tokyo, Japan More articles by this author , Haruki KumeHaruki Kume Tokyo, Japan More articles by this author , Masashi FukayamaMasashi Fukayama Tokyo, Japan More articles by this author , Yukio HommaYukio Homma Tokyo, Japan More articles by this author , and Yoshinori MurakamiYoshinori Murakami Tokyo, Japan More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2012.02.1175AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Tumor suppressor CADM1 (cell adhesion molecule 1) belongs to the immunoglobulin-superfamily cell adhesion molecules (IgCAMs) and participates in cell-cell adhesion activity in various epithelia, including those of urinary bladder. On the other hand, CADM1 is frequently inactivated in a variety of human cancers chiefly by gene promoter methylation, especially in their advanced stages. In this study, we investigated possible involvement of CADM1 in bladder cancer. METHODS CADM1 expression in 11 human bladder cancer cell lines was examined by RT-PCR analysis and western blotting analysis. The methylation status of the CADM1 gene promoter in bladder cancer cell lines was examined by pyrosequencing analysis. CADM1 expression in 147 human primary bladder cancers was examined by immunohistochemical analysis. Cadm1-deficient mice as well as the wild-type C57BL/6 mice were administrated 0.05% N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN), an established bladder carcinogen for mice, in the drinking water for 20 weeks. Any human examination was conducted according to the protocol approved by the research ethics committee of Graduated School of Medicine, The University of Tokyo. RESULTS CADM1 expression was absent or greatly reduced in 6 of 11 human bladder cancer cell lines. The promoter methylation of the CADM1 gene was observed in 4 of those 6 cell lines. CADM1 was expressed along the cell membrane in normal urothelium of human bladder. On the other hand, membranous expression was lost or altered in 92 (63%) of 147 primary bladder cancers. Loss or aberrant expression of CADM1 was significantly correlated with higher pT stages (pTa < pT1 < pT2-4), higher nuclear grade (G1-2 < G3). Moreover, loss or aberrant expression was closely correlated with poor prognosis (P < 0.001) and was an independent prognostic factor in multivariate analysis (P = 0.021) in 112 patients treated with radical cystectomy. Administration of BBN developed invasive bladder cancers (pT2-4) at significantly higher incidence in Cadm1-deficient mice than in the wild-type mice (P = 0.025). CONCLUSIONS The disruption of CADM1 would be involved in the progression of bladder cancers, especially in the invasion and metastasis, and could provide a prognostic marker in invasive bladder cancer. © 2012 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 187Issue 4SApril 2012Page: e434 Advertisement Copyright & Permissions© 2012 by American Urological Association Education and Research, Inc.MetricsAuthor Information Taketo Kawai Tokyo, Japan More articles by this author Akiteru Goto Akita, Japan More articles by this author Masayoshi Nagata Tokyo, Japan More articles by this author Miwako Iwai Tokyo, Japan More articles by this author Teppei Morikawa Tokyo, Japan More articles by this author Shigeki Morita Tokyo, Japan More articles by this author Haruki Kume Tokyo, Japan More articles by this author Masashi Fukayama Tokyo, Japan More articles by this author Yukio Homma Tokyo, Japan More articles by this author Yoshinori Murakami Tokyo, Japan More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Organ Specificity of the Bladder Carcinogen 4-Aminobiphenyl in Inducing DNA Damage and Mutation in Mice

Aromatic amines are a widespread class of environmental contaminants present in various occupational settings and tobacco smoke. Exposure to aromatic amines is a major risk factor for bladder cancer development. The etiologic involvement of aromatic amines in the genesis of bladder cancer is attributable to their ability to form DNA adducts, which upon eluding repair and causing mispairing during replication, may initiate mutagenesis. We have investigated the induction of DNA adducts in relation to mutagenesis in bladder and various nontarget organs of transgenic Big Blue mice treated weekly (i.p.) with a representative aromatic amine compound, 4-aminobiphenyl (4-ABP), for six weeks, followed by a six-week recovery period. We show an organ-specificity of 4-ABP in inducing repair-resistant DNA adducts in bladder, kidney, and liver of carcinogen-treated animals, which accords with the bioactivation pathway of this chemical in the respective organs. In confirmation, we show a predominant and sustained mutagenic effect of 4-ABP in bladder, and much weaker but significant mutagenicity of 4-ABP in the kidney and liver of carcinogen-treated mice, as reflected by the elevation of background cII mutant frequency in the respective organs. The spectrum of mutations produced in bladder of 4-ABP-treated mice matches the known mutagenic properties of 4-ABP-DNA adducts, as verified by the preponderance of induced mutations occurring at G:C base pairs (82.9%), with the vast majority being G:C→T:A transversions (47.1%). Our data support a possible etiologic role of 4-ABP in bladder carcinogenesis and provide a mechanistic view on how DNA adduct-driven mutagenesis, specifically targeted to bladder urothelium, may account for organ-specific tumorigenicity of this chemical.

164 Aberration of a cell adhesion molecule, CADM1, and its pathological or biological significance in urinary bladder cancer

INTRODUCTION AND OBJECTIVES: Tumor suppressor CADM1 (cell adhesion molecule 1) belongs to the immunoglobulin-superfamily cell adhesion molecules (IgCAMs) and participates in cell-cell adhesion activity in various epithelia, including those of urinary bladder. On the other hand, CADM1 is frequently inactivated in a variety of human cancers chiefly by gene promoter methylation, especially in their advanced stages. In this study, we investigated possible involvement of CADM1 in bladder cancer. METHODS: CADM1 expression in 11 human bladder cancer cell lines was examined by RT-PCR analysis and western blotting analysis. The methylation status of the CADM1 gene promoter in bladder cancer cell lines was examined by pyrosequencing analysis. CADM1 expression in 147 human primary bladder cancers was examined by immunohistochemical analysis. Cadm1-deficient mice as well as the wild-type C57BL/6 mice were administrated 0.05% N-butyl-N(4-hydroxybutyl)nitrosamine (BBN), an established bladder carcinogen for mice, in the drinking water for 20 weeks. Any human examination was conducted according to the protocol approved by the research ethics committee of Graduated School of Medicine, The University of Tokyo. RESULTS: CADM1 expression was absent or greatly reduced in 6 of 11 human bladder cancer cell lines. The promoter methylation of the CADM1 gene was observed in 4 of those 6 cell lines. CADM1 was expressed along the cell membrane in normal urothelium of human bladder. On the other hand, membranous expression was lost or altered in 92 (63%) of 147 primary bladder cancers. Loss or aberrant expression of CADM1 was significantly correlated with higher pT stages (pTa pT1 pT2-4), higher nuclear grade (G1-2 G3). Moreover, loss or aberrant expression was closely correlated with poor prognosis (P 0.001) and was an independent prognostic factor in multivariate analysis (P 0.021) in 112 patients treated with radical cystectomy. Administration of BBN developed invasive bladder cancers (pT2-4) at significantly higher incidence in Cadm1-deficient mice than in the wild-type mice (P 0.025). CONCLUSIONS: The disruption of CADM1 would be involved in the progression of bladder cancers, especially in the invasion and metastasis, and could provide a prognostic marker in invasive bladder cancer. Source of Funding: None

Letter: The Risk of Bladder Cancer in Korean Diabetic Subjects Treated with Pioglitazone (Diabetes Metab J2012;36:371-8)

Type 2 diabetes mellitus is characterized by insulin resistance as well as progressive pancreatic β-cell dysfunction. Thiazoli dinediones (TZDs) are a class of hypoglycemic medications that influence insulin sensitivity in peripheral tissue [1]. Piogl itazone is a TZD, peroxisome proliferator-activated receptor (PPAR)-γ ligand used in the treatment of type 2 diabetic patients [2]. Many preclinical trials have demonstrated that PPAR-γ is a potential molecular target for the development of bladder cancer. Yoshimura et al. [3] found PPAR-γ mRNA in bladder cancer samples. Furthermore, immunohistochemistry revealed that the protein expression of PPAR-γ was significantly higher with increasing grade and increasing stage of bladder cancer [3]. In male rats exposed to muraglitazar, a dual human PAPR-α/γ agonist, there was a dose-related increased incidence of transitional cell papilloma and carcinoma of the urinary bladder [4]. Lubet et al. [5] also reported that another PPAR-γ agonist, rosiglitazone, enhanced bladder tumors in rats pretreated with N-(4-hydroxybutyl)-N-(butyl)-nitrosamine (BBN), a known DNA-reactive bladder carcinogen in several species. However, the mechanisms underlying this pro-tumor potential of pioglitazone for bladder cancer are not fully understood. In the large prospective pioglitazone clinical trial in macrovascular events (PROactive) study, 14 bladder cancers occurred in the pioglitazone arm (0.5%) versus 6 in the placebo arm (0.2%) [6], and in September 2010, the U.S. Food and Drug