| 1. |
|
|
| 2. |
- Machiela, Mitchell J, et al.
(författare)
-
Female chromosome X mosaicism is age-related and preferentially affects the inactivated X chromosome
- 2016
-
Ingår i: Nature Communications. - : Nature Publishing Group. - 2041-1723. ; 7
-
Tidskriftsartikel (refereegranskat)abstract
- To investigate large structural clonal mosaicism of chromosome X, we analysed the SNP microarray intensity data of 38,303 women from cancer genome-wide association studies (20,878 cases and 17,425 controls) and detected 124 mosaic X events >2 Mb in 97 (0.25%) women. Here we show rates for X-chromosome mosaicism are four times higher than mean autosomal rates; X mosaic events more often include the entire chromosome and participants with X events more likely harbour autosomal mosaic events. X mosaicism frequency increases with age (0.11% in 50-year olds; 0.45% in 75-year olds), as reported for Y and autosomes. Methylation array analyses of 33 women with X mosaicism indicate events preferentially involve the inactive X chromosome. Our results provide further evidence that the sex chromosomes undergo mosaic events more frequently than autosomes, which could have implications for understanding the underlying mechanisms of mosaic events and their possible contribution to risk for chronic diseases.
|
|
| 3. |
- Figueroa, Jonine D., et al.
(författare)
-
Identification of a novel susceptibility locus at 13q34 and refinement of the 20p12.2 region as a multi-signal locus associated with bladder cancer risk in individuals of European ancestry
- 2016
-
Ingår i: Human Molecular Genetics. - : Oxford University Press. - 0964-6906 .- 1460-2083. ; 25:6, s. 1203-1214
-
Tidskriftsartikel (refereegranskat)abstract
- Candidate gene and genome-wide association studies (GWAS) have identified 15 independent genomic regions associated with bladder cancer risk. In search for additional susceptibility variants, we followed up on four promising single-nucleotide polymorphisms (SNPs) that had not achieved genome-wide significance in 6911 cases and 11 814 controls (rs6104690, rs4510656, rs5003154 and rs4907479, P < 1 × 10−6), using additional data from existing GWAS datasets and targeted genotyping for studies that did not have GWAS data. In a combined analysis, which included data on up to 15 058 cases and 286 270 controls, two SNPs achieved genome-wide statistical significance: rs6104690 in a gene desert at 20p12.2 (P = 2.19 × 10−11) and rs4907479 within the MCF2L gene at 13q34 (P = 3.3 × 10−10). Imputation and fine-mapping analyses were performed in these two regions for a subset of 5551 bladder cancer cases and 10 242 controls. Analyses at the 13q34 region suggest a single signal marked by rs4907479. In contrast, we detected two signals in the 20p12.2 region—the first signal is marked by rs6104690, and the second signal is marked by two moderately correlated SNPs (r2 = 0.53), rs6108803 and the previously reported rs62185668. The second 20p12.2 signal is more strongly associated with the risk of muscle-invasive (T2-T4 stage) compared with non-muscle-invasive (Ta, T1 stage) bladder cancer (case–case P ≤ 0.02 for both rs62185668 and rs6108803). Functional analyses are needed to explore the biological mechanisms underlying these novel genetic associations with risk for bladder cancer.
|
|
| 4. |
- Yang, Meng, et al.
(författare)
-
Prediagnosis leukocyte telomere length and risk of ovarian cancer
- 2016
-
Ingår i: Clinical Cancer Research. - : American Association for Cancer Research. - 1078-0432 .- 1557-3265. ; 22
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Introduction: Ovarian cancer is characterized by substantial genomic instability. Telomeres, which protect the physical integrity of chromosomes, are shortened by each cell division, and evidence supports that longer telomeres may reduce genomic instability. While retrospective studies generally support an inverse association of telomere length and ovarian cancer risk, the measures of telomere length after diagnosis may be influenced by treatment. Therefore, we examined the relationship between leukocyte telomere length (LTL) assessed prior to diagnosis and risk of ovarian cancer in three prospective studies. Methods: We used buffy coat samples collected from healthy participants in the Nurses' Health Study (NHS), NHSII, and the Northern Sweden Health and Disease Study (NSHDS). Women who later developed ovarian cancer were matched to one or two controls on age, menopausal status, and date of blood collection. LTL was assessed using quantitative PCR-based assays in 5 batches with coefficients of variation of 10-15%. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using conditional logistic regression, based on study-specific quartiles in controls, for each study separately. We used fixed-effects models for meta-analysis. Multivariate models adjusted for oral contraceptive use, tubal ligation, family history of ovarian cancer, parity, smoking status, and body mass index. Results: In total, there were 487 cases and 810 controls across the three studies. The mean age at blood collection ranged from 45 (NHSII) to 57 (NHS) years. In unadjusted and multivariate models, we observed a suggestion of an inverse association between LTL and ovarian cancer risk in each study, although none of the trend tests were statistically significant. In a meta-analysis of the multivariate adjusted models, women in the longest versus shortest quartile of LTL had a non-significant 26% lower risk of ovarian cancer (OR=0.74; 95%CI=0.49-1.12; p-trend=0.33). Conclusion: In this first prospective study of telomere length and ovarian cancer risk, we observed that longer leukocyte telomere length was suggestively associated with lower ovarian cancer risk. Given that serous tumors are more likely to exhibit genomic instability, we are currently evaluating the association for this subtype as well as conducting pooled analyses with common quartile cut points across studies.
|
|
