Telomere length, cigarette smoking, and bladder cancer risk in men and women
ABSTRACT Truncated telomeres are among the defining characteristics of most carcinomas. Given the role of telomeres in tumorigenesis, we reasoned that constitutionally short telomeres might be associated with an increased risk of bladder cancer. Using quantitative real-time PCR, we measured relative telomere length in bladder cancer cases and healthy controls and evaluated the association between telomere length, cigarette smoking, and bladder cancer risk in a case-control study nested within the Health Professionals Follow-up Study and a case-control study nested within the Nurses' Health Study. Telomeres were significantly shorter in bladder cancer cases (n = 184) than in controls (n = 192). The mean relative telomere length in cases was 0.23 (SD, 0.16) versus 0.27 (SD, 0.15) in controls (P = 0.001). The adjusted odds ratio for bladder cancer was 1.88 (95% confidence interval, 1.05, 3.36) for individuals in the quartile with the shortest telomeres as compared with individuals in the quartile with the longest telomeres (P(trend) = 0.006). We observed a statistically significant difference in telomere length among men and women (P < 0.001); however, the interaction between gender, telomere length, and bladder cancer risk was not significant. We also observed a significant difference in telomere length across categories of pack-years of smoking (P = 0.01). These findings suggest that truncated telomeres are associated with an increased risk of bladder cancer.
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ABSTRACT: Studies have reported an association between the TERT rs2736098 single nucleotide polymorphism (SNP) and cancer susceptibility, but the results remain inconclusive. Toprovide a more precise estimation of the relationship, a meta-analysis of 8 published studies including 8,070 cases and 10,239 controls was performed. Stratification by sample size, genotyping method, source of controls and ethnicity were used to explore the source of heterogeneity. In the overall analysis, no significant association was found between the TERT rs2736098 polymorphism and cancer risk. However, the result showed the rs2736098 was significantly associated with an increased cancer risk and the heterogeneity was effectively decreased for homozygote comparison by removal of two studies: OR = 1.337 (95% CI = 1.183-1.511; Pheterogeneity = 0.087). In the subgroup analysis by ethnicity, a significantly increased risk of cancers was found among Asians (OR = 1.413, 95% CI = 1.187-1.683 for AA versus GG). Our meta-analysis did not show that the TERT rs2736098 plays an important role in cancer risk. More studies with larger sample size and well-matched controls are needed to confirm the findings.Asian Pacific journal of cancer prevention: APJCP 10/2012; 13(10):4943-6. DOI:10.7314/APJCP.2012.13.10.4943 · 1.50 Impact Factor
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ABSTRACT: Short telomeres in peripheral blood leukocytes are associated with older age and age-related diseases. We tested the hypotheses that short telomeres are associated with both increased cancer mortality and all-cause mortality. Individuals (n = 64637) were recruited from 1991 onwards from two Danish prospective cohort studies: the Copenhagen City Heart Study and the Copenhagen General Population Study. All had telomere length measured by quantitative polymerase chain reaction and the genotypes rs1317082 (TERC), rs7726159 (TERT), and rs2487999 (OBFC1) determined. The sum of telomere-shortening alleles from these three genotypes was calculated. We conducted Cox regression analyses and instrumental variable analyses using the allele sum as an instrument. All statistical tests were two-sided. Among 7607 individuals who died during follow-up (0-22 years, median = 7 years), 2420 had cancer and 2633 had cardiovascular disease as causes of death. Decreasing telomere length deciles were associated with increasing all-cause mortality (P trend = 2*10(-15)). The multivariable-adjusted hazard ratio of all-cause mortality was 1.40 (95% confidence interval [CI] = 1.25 to 1.57) for individuals in the shortest vs the longest decile. Results were similar for cancer mortality and cardiovascular mortality. Telomere length decreased 69 base pairs (95% CI = 61 to 76) per allele for the allele sum, and the per-allele hazard ratio for cancer mortality was 0.95 (95% CI = 0.91 to 0.99). Allele sum was not associated with cardiovascular, other, or all-cause mortality. Short telomeres in peripheral blood leukocytes were associated with high mortality in association analyses. In contrast, genetically determined short telomeres were associated with low cancer mortality but not with all-cause mortality. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: email@example.com.CancerSpectrum Knowledge Environment 06/2015; 107(6). DOI:10.1093/jnci/djv074 · 15.16 Impact Factor
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ABSTRACT: Abstract Telomere length (TL), the length of repeated DNA sequence that forms protective caps at the end of chromosomes, has emerged as a novel biomarker of cell aging and oxidative stress. There is increasing research exploring the associations of smoking and perceived stress with TL, and the results are inconsistent. This study aimed to examine whether smoking and perceived stress were associated with shortened salivary TL among primary caregivers of children with disabilities. Using a quantitative polymerase chain reaction method, salivary TL was assessed among 89 caregivers aged 19-69 years (87% were women) who took care of disabled children in the Patagonia Region, Chile. Interviewer-administered questionnaires were used to collect information on sociodemographic and lifestyle behaviors. The 14-item Perceived Stress Scale was used to assess perceived stress. Mean relative TL was 0.92 (standard error=0.03). Smokers had age-adjusted mean TL that was 0.07 units lower (beta=-0.07, standard error=0.03; p=0.012) than non-smokers. Smokers were 2.17 times more likely to have shorter TL (<0.73, the lowest quartile of TL) than non-smokers (odds ratio =3.17; 95% confidence interval=1.05-9.52) with adjustment for age and perceived stress. Caregivers with higher perceived stress were 2.13 times more likely to have shorter TL (odds ratio=3.13; 95% confidence interval=1.03-9.55) than caregivers with lower perceived stress after adjustment for age and smoking. This study provides the first evidence of strong associations between smoking and perceived stress and shortened salivary TL among caregivers of children with disabilities. Larger studies with detailed information on smoking status are warranted to confirm our findings.Stress (Amsterdam, Netherlands) 09/2014; 18(1):1-38. DOI:10.3109/10253890.2014.969704 · 3.46 Impact Factor