Project description:Little is known whether genetic variants identified in genome-wide association studies interact to increase bladder cancer risk. Recently, we identified two- and three-variant combinations associated with a particular increase of bladder cancer risk in a urinary bladder cancer case-control series (Leibniz Research Centre for Working Environment and Human Factors at TU Dortmund (IfADo), 1501 cases, 1565 controls). In an independent case-control series (Nijmegen Bladder Cancer Study, NBCS, 1468 cases, 1720 controls) we confirmed these two- and three-variant combinations. Pooled analysis of the two studies as discovery group (IfADo-NBCS) resulted in sufficient statistical power to test up to four-variant combinations by a logistic regression approach. The New England and Spanish Bladder Cancer Studies (2080 cases and 2167 controls) were used as a replication series. Twelve previously identified risk variants were considered. The strongest four-variant combination was obtained in never smokers. The combination of rs1014971[AA] near apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like 3A (APOBEC3A) and chromobox homolog 6 (CBX6), solute carrier family 1s4 (urea transporter), member 1 (Kidd blood group) (SLC14A1) exon single nucleotide polymorphism (SNP) rs1058396[AG, GG], UDP glucuronosyltransferase 1 family, polypeptide A complex locus (UGT1A) intron SNP rs11892031[AA] and rs8102137[CC, CT] near cyclin E1 (CCNE1) resulted in an unadjusted odds ratio (OR) of 2.59 (95% CI = 1.93-3.47; P = 1.87 × 10-10), while the individual variant ORs ranged only between 1.11 and 1.30. The combination replicated in the New England and Spanish Bladder Cancer Studies (ORunadjusted = 1.60, 95% CI = 1.10-2.33; P = 0.013). The four-variant combination is relatively frequent, with 25% in never smoking cases and 11% in never smoking controls (total study group: 19% cases, 14% controls). In conclusion, we show that four high-risk variants can statistically interact to confer increased bladder cancer risk particularly in never smokers.
Project description:Glucuronide conjugates of 4-aminobiphenyl and its N-hydroxy metabolite can be rapidly hydrolyzed in acidic urine to undergo further metabolic activation and form DNA adducts in the urothelium. We conducted a large multicenter case-control study in Spain to explore the etiology of bladder cancer and evaluated the association between urine pH and bladder cancer risk, alone and in combination with cigarette smoking. In total, 712 incident urothelial cell carcinoma cases and 611 hospital controls directly measured their urine pH with dipsticks twice a day (first void in the morning and early in the evening) during four consecutive days 2 weeks after hospital discharge. We found that a consistently acidic urine pH ?6.0 was associated with an increased risk of bladder cancer [odds ratio (OR) = 1.5, 95% confidence interval (CI): 1.2-1.9] compared with all other subjects. Furthermore, risk estimates for smoking intensity and risk of bladder cancer among current smokers tended to be higher for those with a consistently acidic urine (OR = 8.8, 11.5 and 23.8) compared with those without (OR = 4.3, 7.7 and 5.8, respectively, for 1-19, 20-29 and 30+ cigarettes per day; P(interaction) for 30+ cigarettes per day = 0.024). These results suggest that urine pH, which is determined primarily by diet and body surface area, may be an important modifier of smoking and risk of bladder cancer.
Project description:LATS1, the large tumor suppressor 1 gene, encodes for a serine/threonine kinase protein and is implicated in cell cycle progression. LATS1 is down-regulated in various human cancers, such as breast cancer, and astrocytoma. Point mutations in LATS1 were reported in human sarcomas. Additionally, loss of heterozygosity of LATS1 chromosomal region predisposes to breast, ovarian, and cervical tumors. In the current study, we investigated LATS1 genetic variations including single nucleotide polymorphisms (SNPs), in 28 Egyptian patients with either urinary bladder or colon cancers. The LATS1 gene was amplified and sequenced and the expression of LATS1 at the RNA level was assessed in 12 urinary bladder cancer samples. We report, the identification of a total of 29 variants including previously identified SNPs within LATS1 coding and non-coding sequences. A total of 18 variants were novel. Majority of the novel variants, 13, were mapped to intronic sequences and un-translated regions of the gene. Four of the five novel variants located in the coding region of the gene, represented missense mutations within the serine/threonine kinase catalytic domain. Interestingly, LATS1 RNA steady state levels was lost in urinary bladder cancerous tissue harboring four specific SNPs (16045 + 41736 + 34614 + 56177) positioned in the 5'UTR, intron 6, and two silent mutations within exon 4 and exon 8, respectively. This study identifies novel single-base-sequence alterations in the LATS1 gene. These newly identified variants could potentially be used as novel diagnostic or prognostic tools in cancer.
Project description:The etiology of bladder cancer among never smokers without occupational or environmental exposure to established urothelial carcinogens remains unclear. Urinary mutagenicity is an integrative measure that reflects recent exposure to genotoxic agents. Here, we investigated its potential association with bladder cancer in rural northern New England. We analyzed 156 bladder cancer cases and 247 cancer-free controls from a large population-based case-control study conducted in Maine, New Hampshire, and Vermont. Overnight urine samples were deconjugated enzymatically and the extracted organics were assessed for mutagenicity using the plate-incorporation Ames assay with the Salmonella frameshift strain YG1041 + S9. Logistic regression was used to estimate the odds ratios (OR) and 95% confidence intervals (CI) of bladder cancer in relation to having mutagenic versus nonmutagenic urine, adjusted for age, sex, and state, and stratified by smoking status (never, former, and current). We found evidence for an association between having mutagenic urine and increased bladder cancer risk among never smokers (OR = 3.8, 95% CI: 1.3-11.2) but not among former or current smokers. Risk could not be estimated among current smokers because nearly all cases and controls had mutagenic urine. Urinary mutagenicity among never-smoking controls could not be explained by recent exposure to established occupational and environmental mutagenic bladder carcinogens evaluated in our study. Our findings suggest that among never smokers, urinary mutagenicity potentially reflects genotoxic exposure profiles relevant to bladder carcinogenesis. Future studies are needed to replicate our findings and identify compounds and their sources that influence bladder cancer risk.
Project description:BACKGROUND: The association of transitional cell carcinomas of the bladder (TCB) with Schistosoma haematobium suggested a possible role of infections in the aetiology of TCB. METHODS: In all, 114 TCB cases and 140 hospital controls from Pordenone Province were enrolled within an Italian multi-centric case-control study. Urine samples were screened for DNA from five human polyomaviruses (HPyV) (JCV, BKV, MCV, WUV, and KIV); SV40; and 22 mucosal human papillomaviruses (HPV) using highly sensitive PCR assays. Odds ratios (ORs) and corresponding confidence intervals (CIs) were computed for risk of TCB by HPyV- or HPV-positivity using unconditional logistic regression. RESULTS: Human polyomavirus prevalence was similar in TCB cases (71.7%) and controls (77.7%) (OR for TCB=0.85; 95% CI: 0.45-1.61). JCV was the most frequently detected HPyV type. No individual HPyV showed a significant association. Among cases, HPyV-positivity was not associated with tumour characteristics, but it was significantly lower in women than men and among current and former smokers than never smokers. Human papillomavirus was detected in seven cases and five controls (OR=1.52; 95% CI: 0.42-5.45). CONCLUSION: The present small study does not support an involvement of HPyV or HPV infection in TCB aetiology in immunocompetent individuals. Differences in HPyV-positivity by sex and smoking may derive from differences in either acquisition or persistence of the infection.
Project description:This study sought to determine the role of copy number variants (CNV) combined with other genetic variants in the Glutathione S-transferases Mu class1 (GSTM1) promoter in the development of urinary bladder cancer. TaqMan real-time PCR and direct sequencing were used to determine genetic variants. Haploblocks and haplotype were constructed and estimated by Haploview and Phase, respectively. Logistic regression revealed a significantly decreased bladder cancer risk in subjects with at least 2 copies of GSTM1 (OR=0.56; 95%CI=0.39-0.81) but not in those with 1 copy of the gene. GSTM1 promoter screening revealed an insertion variant (-1543TTCT) and 14 single nucleotide polymorphisms (SNPs) (-1529C>G, -1490A>G, -1143A>G, -888A>T, -498G>C, -486C>G, -471C>T, -426G>A, -344C>T, -343A>T, -341C>T, -339C>T, -304G>A, and -164C>T). Four haploblocks were evident by Haploview. There was no significant association between any single SNP/haplotype and bladder cancer risk. However, when stratified by copy number, the two copy carriers with the -1543 insertion had decreased bladder cancer risk (OR, 0.58; 95%CI, 0.32-0.10) and similar results were found in two copy carriers with -888 A, -486G, - 344 C, -343 A, -341 C allele and haplotype INS(-1543)-C(-1529)-A(-1429) in LD block 1, A(-1143)-A(-888) in LD block 2, C(-498)-G(-486)-T(-471) in LD block 3, C(-344)-A(-343)-C(-341)-C(-339) and C(-344)-A(-343)-C(-341)-T(-339) in LD block 4. These results suggest that GSTM1 CNV is a better predictor of bladder cancer susceptibility than measuring presence/absence of GSTM1 and other genetic variants also can modify bladder cancer risk.
Project description:Genome-wide association studies (GWAS) have been successful in the identification of the several urinary bladder cancer (UBC) susceptibility loci, pointing towards novel genes involved in tumor development. Despite that, functional characterization of the identified variants remains challenging, as they mostly map to poorly understood, non-coding regions. Recently, two of the UBC risk variants (PSCA and UGT1A) were confirmed to have functional consequences. They were shown to modify bladder cancer risk by influencing gene expression in an allele-specific manner. Although the role of the other UBC risk variants is unknown, it can be hypothesized-based on studies from different cancer types-that they influence cancer susceptibility by alterations in regulatory networks. The insight into UBC heritability gained through GWAS and further functional studies can impact on cancer prevention and screening, as well as on the development of new biomarkers and future personalized therapies.