| 1. |
- Butt, Salma, et al.
(författare)
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Genetic predisposition, parity, age at first childbirth and risk for breast cancer.
- 2012
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Ingår i: BMC Research Notes. - : Springer Science and Business Media LLC. - 1756-0500. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Recent studies have identified several single-nucleotide polymorphisms (SNPs) associated with the risk of breast cancer and parity and age at first childbirth are well established and important risk factors for breast cancer. The aim of the present study was to examine the interaction between these environmental factors and genetic variants on breast cancer risk.METHODS: The Malmö Diet and Cancer Study (MDCS) included 17 035 female participants, from which 728 incident breast cancer cases were matched to 1448 controls. The associations between 14 SNPs and breast cancer risk were investigated in different strata of parity and age at first childbirth. A logistic regression analysis for the per allele risk, adjusted for potential confounders yielded odds ratios (OR) with 95% confidence intervals (CI).RESULTS: Six of the previously identified SNPs showed a statistically significant association with breast cancer risk: rs2981582 (FGFR2), rs3803662 (TNRC9), rs12443621 (TNRC9), rs889312 (MAP3K1), rs3817198 (LSP1) and rs2107425 (H19). We could not find any statistically significant interaction between the effects of tested SNPs and parity/age at first childbirth on breast cancer risk after adjusting for multiple comparisons.CONCLUSIONS: The results of this study are in agreement with previous studies of null interactions between tested SNPs and parity/age at first childbirth with regard to breast cancer risk.
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| 2. |
- Harlid, Sophia, 1978-, et al.
(författare)
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A candidate CpG SNP approach identifies a breast cancer associated ESR1-SNP
- 2011
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Ingår i: International Journal of Cancer. - : Wiley-Blackwell. - 0020-7136 .- 1097-0215. ; 129:7, s. 1689-1698
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Tidskriftsartikel (refereegranskat)abstract
- Altered DNA methylation is often seen in malignant cells, potentially contributing to carcinogenesis by suppressing gene expression. We hypothesized that heritable methylation potential might be a risk factor for breast cancer and evaluated possible association with breast cancer for single nucleotide polymorphisms (SNPs) either involving CpG sequences in extended 5'-regulatory regions of candidate genes (ESR1, ESR2, PGR, and SHBG) or CpG and missense coding SNPs in genes involved in methylation (MBD1, MECP2, DNMT1, MGMT, MTHFR, MTR, MTRR, MTHFD1, MTHFD2, BHMT, DCTD, and SLC19A1). Genome-wide searches for genetic risk factors for breast cancers have in general not investigated these SNPs, because of low minor allele frequency or weak haplotype associations. Genotyping was performed using Mass spectrometry-Maldi-Tof in a screening panel of 538 cases and 1,067 controls. Potential association to breast cancer was identified for 15 SNPs and one of these SNPs (rs7766585 in ESR1) was found to associate strongly with breast cancer, OR 1.30 (95% CI 1.17-1.45; p-value 2.1 × 10(-6) ), when tested in a verification panel consisting of 3,211 unique breast cancer cases and 4,223 unique controls from five European biobank cohorts. In conclusion, a candidate gene search strategy focusing on methylation-related SNPs did identify a SNP that associated with breast cancer at high significance.
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| 3. |
- Harlid, Sophia, 1978-, et al.
(författare)
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Combined effect of low-penetrant SNPs on breast cancer risk
- 2012
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Ingår i: British Journal of Cancer. - London : Nature Publishing Group. - 0007-0920 .- 1532-1827. ; 106:2, s. 389-396
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Although many low-penetrant genetic risk factors for breast cancer have been discovered, knowledge about the effect of multiple risk alleles is limited, especially in women <50 years. We therefore investigated the association between multiple risk alleles and breast cancer risk as well as individual effects according to age-approximated pre- and post-menopausal status.METHODS: Ten previously described breast cancer-associated single-nucleotide polymorphisms (SNPs) were analysed in a joint European biobank-based study comprising 3584 breast cancer cases and 5063 cancer-free controls. Genotyping was performed using MALDI-TOF mass spectrometry, and odds ratios were estimated using logistic regression.RESULTS: Significant associations with breast cancer were confirmed for 7 of the 10 SNPs. Analysis of the joint effect of the original 10 as well as the statistically significant 7 SNPs (rs2981582, rs3803662, rs889312, rs13387042, rs13281615, rs3817198 and rs981782) found a highly significant trend for increasing breast cancer risk with increasing number of risk alleles (P-trend 5.6 x 10(-20) and 1.5 x 10(-25), respectively). Odds ratio for breast cancer of 1.84 (95% confidence interval (CI): 1.59-2.14; 10 SNPs) and 2.12 (95% CI: 1.80-2.50; 7 SNPs) was seen for the maximum vs the minimum number of risk alleles. Additionally, one of the examined SNPs (rs981782 in HCN1) had a protective effect that was significantly stronger in premenopausal women (P-value: 7.9 x 10(-4)).CONCLUSION: The strongly increasing risk seen when combining many low-penetrant risk alleles supports the polygenic inheritance model of breast cancer. British Journal of Cancer (2012) 106, 389-396. doi:10.1038/bjc.2011.461 www.bjcancer.com Published online 1 November 2011 (C) 2012 Cancer Research UK
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| 4. |
- Harlid, Sophia, 1978-, et al.
(författare)
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CpG sites associated with cigarette smoking : analysis of epigenome-wide data from the Sister Study.
- 2014
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Ingår i: Journal of Environmental Health Perspectives. - : Environmental Health Perspectives. - 0091-6765 .- 1552-9924. ; 122:7, s. 673-8
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Smoking increases the risk of many diseases, and it is also linked to blood DNA methylation changes that may be important in disease etiology.OBJECTIVES: We sought to identify novel CpG sites associated with cigarette smoking.METHODS: We used two epigenome-wide data sets from the Sister Study to identify and confirm CpG sites associated with smoking. One included 908 women with methylation measurements at 27,578 CpG sites using the HumanMethylation27 BeadChip; the other included 200 women with methylation measurements for 473,844 CpG sites using the HumanMethylation450 BeadChip. Significant CpGs from the second data set that were not included in the 27K assay were validated by pyrosequencing in a subset of 476 samples from the first data set.RESULTS: Our study successfully confirmed smoking associations for 9 previously established CpGs and identified 2 potentially novel CpGs: cg26764244 in GNG12 (p = 9.0 × 10-10) and cg22335340 in PTPN6 (p = 2.9 × 10-05). We also found strong evidence of an association between smoking status and cg02657160 in CPOX (p = 7.3 × 10-7), which has not been previously reported. All 12 CpGs were undermethylated in current smokers and showed an increasing percentage of methylation in former and never-smokers.CONCLUSIONS: We identified 2 potentially novel smoking related CpG sites, and provided independent replication of 10 previously reported CpGs sites related to smoking, one of which is situated in the gene CPOX. The corresponding enzyme is involved in heme biosynthesis, and smoking is known to increase heme production. Our study extends the evidence base for smoking-related changes in DNA methylation.
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| 5. |
- Harlid, Sophia, 1978-, et al.
(författare)
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Interactive effect of genetic susceptibility with height, body mass index, and hormone replacement therapy on the risk of breast cancer.
- 2012
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Ingår i: BMC Women's Health. - : Springer Science and Business Media LLC. - 1472-6874. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Breast cancer today has many established risk factors, both genetic and environmental, but these risk factors by themselves explain only part of the total cancer incidence. We have investigated potential interactions between certain known genetic and phenotypic risk factors, specifically nine single nucleotide polymorphisms (SNPs) and height, body mass index (BMI) and hormone replacement therapy (HRT).METHODS: We analyzed samples from three different study populations: two prospectively followed Swedish cohorts and one Icelandic case-control study. Totally 2884 invasive breast cancer cases and 4508 controls were analysed in the study. Genotypes were determined using Mass spectrometry-Maldi-TOF and phenotypic variables were derived from measurements and/or questionnaires. Odds Ratios and 95% confidence intervals were calculated using unconditional logistic regression with the inclusion of an interaction term in the logistic regression model.RESULTS: One SNP (rs851987 in ESR1) tended to interact with height, with an increasingly protective effect of the major allele in taller women (p = 0.007) and rs13281615 (on 8q24) tended to confer risk only in non users of HRT (p-for interaction = 0.03). There were no significant interactions after correction for multiple testing.CONCLUSIONS: We conclude that much larger sample sets would be necessary to demonstrate interactions between low-risk genetic polymorphisms and the phenotypic variables height, BMI and HRT on the risk for breast cancer. However the present hypothesis-generating study has identified tendencies that would be of interest to evaluate for gene-environment interactions in independent materials.
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| 6. |
- Markunas, Christina A, et al.
(författare)
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Identification of DNA methylation changes in newborns related to maternal smoking during pregnancy.
- 2014
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Ingår i: Journal of Environmental Health Perspectives. - : Environmental Health Perspectives. - 0091-6765 .- 1552-9924. ; 122:10, s. 1147-53
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Maternal smoking during pregnancy is associated with significant infant morbidity and mortality, and may influence later disease risk. One mechanism by which smoking (and other environmental factors) might have long-lasting effects is through epigenetic modifications such as DNA methylation.OBJECTIVES: We conducted an epigenome-wide association study (EWAS) investigating alterations in DNA methylation in infants exposed in utero to maternal tobacco smoke, using the Norway Facial Clefts Study.METHODS: The Illumina HumanMethylation450 BeadChip was used to assess DNA methylation in whole blood from 889 infants shortly after delivery. Of 889 mothers, 287 reported smoking-twice as many smokers as in any previous EWAS of maternal smoking. CpG sites related to maternal smoking during the first trimester were identified using robust linear regression.RESULTS: We identified 185 CpGs with altered methylation in infants of smokers at genome-wide significance (q-value < 0.05; mean Δβ = ± 2%). These correspond to 110 gene regions, of which 7 have been previously reported and 10 are newly confirmed using publicly available results. Among these 10, the most noteworthy are FRMD4A, ATP9A, GALNT2, and MEG3, implicated in processes related to nicotine dependence, smoking cessation, and placental and embryonic development.CONCLUSIONS: Our study identified 10 genes with newly established links to maternal smoking. Further, we note differences between smoking-related methylation changes in newborns and adults, suggesting possible distinct effects of direct versus indirect tobacco smoke exposure as well as potential differences due to age. Further work would be needed to determine whether these small changes in DNA methylation are biologically or clinically relevant. The methylation changes identified in newborns may mediate the association between in utero maternal smoking exposure and later health outcomes.
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