| 1. |
- Shi, Hong, et al.
(författare)
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Single nucleotide polymorphisms in the 20q13 amplicon genes in relation to breast cancer risk and clinical outcome
- 2011
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Ingår i: Breast Cancer Research and Treatment. - New York : Springer-Verlag New York. - 0167-6806 .- 1573-7217. ; 130:3, s. 905-916
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Tidskriftsartikel (refereegranskat)abstract
- The 20q13 region is frequently amplified/overexpressed in breast tumours. However, the nature of this amplification/overexpression is unknown. Here, we investigated genetic variation in five 20q13 amplicon genes (MYBL2, AURKA, ZNF217, STK4 and PTPN1) and its impact on breast cancer (BC) susceptibility and clinical outcome. As a novel finding, four polymorphisms in STK4 (rs6017452, rs7271519) and AURKA (rs2273535, rs8173) associated with steroid hormone receptor status both in a Swedish population-based cohort of 783 BC cases and in a Polish familial/early onset cohort of 506 BC cases. In the joint analysis, the minor allele carriers of rs6017452 had more often hormone receptor positive tumours (OR 0.57, 95% CI 0.40-0.81), while homozygotes for the minor allele of rs7271519, rs2273535 and rs8173 had more often hormone receptor negative tumours (2.26, 1.30-3.39; 2.39, 1.14-5.01; 2.39, 1.19-4.80, respectively) than homozygotes for the common allele. BC-specific survival analysis of AURKA suggested that the Swedish carriers of the minor allele of rs16979877, rs2273535 and rs8173 might have a worse survival compared with the major homozygotes. The survival probabilities associated with the AURKA genotypes depended on the tumour phenotype. In the Swedish case-control study, associations with BC susceptibility were observed in a dominant model for three MYBL2 promoter polymorphisms (rs619289, P = 0.02; rs826943, P = 0.03 and rs826944, P = 0.02), two AURKA promoter polymorphisms (rs6064389, P = 0.04 and rs16979877, P = 0.02) and one 3'UTR polymorphism in ZNF217 (rs1056948, P = 0.01). In conclusion, our data confirmed the impact of the previously identified susceptibility locus and provided preliminary evidence for novel susceptibility variants in BC. We provided evidence for the first time that genetic variants at 20q13 may affect hormone receptor status in breast tumours and influence tumour aggressiveness and survival of the patients. Future studies are needed to confirm the prognostic value of our findings in the clinic.
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| 2. |
- Thomsen, Hauke, et al.
(författare)
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Inbreeding and homozygosity in breast cancer survival
- 2015
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- Genome-wide association studies (GWASs) help to understand the effects of single nucleotide polymorphisms (SNPs) on breast cancer (BC) progression and survival. We performed multiple analyses on data from a previously conducted GWAS for the influence of individual SNPs, runs of homozygosity (ROHs) and inbreeding on BC survival. (I.) The association of individual SNPs indicated no differences in the proportions of homozygous individuals among short-time survivors (STSs) and long-time survivors (LTSs). (II.) The analysis revealed differences among the populations for the number of ROHs per person and the total and average length of ROHs per person and among LTSs and STSs for the number of ROHs per person. (III.) Common ROHs at particular genomic positions were nominally more frequent among LTSs than in STSs. Common ROHs showed significant evidence for natural selection (iHS, Tajima's D, Fay-Wu's H). Most regions could be linked to genes related to BC progression or treatment. (IV.) Results were supported by a higher level of inbreeding among LTSs. Our results showed that an increased level of homozygosity may result in a preference of individuals during BC treatment. Although common ROHs were short, variants within ROHs might favor survival of BC and may function in a recessive manner.
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| 3. |
- Woltmann, Andrea, et al.
(författare)
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Systematic Pathway Enrichment Analysis of a Genome-Wide Association Study on Breast Cancer Survival Reveals an Influence of Genes Involved in Cell Adhesion and Calcium Signaling on the Patients' Clinical Outcome
- 2014
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9:6, s. e98229-
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Tidskriftsartikel (refereegranskat)abstract
- Genome-wide association studies (GWASs) may help to understand the effects of genetic polymorphisms on breast cancer (BC) progression and survival. However, they give only a focused view, which cannot capture the tremendous complexity of this disease. Therefore, we investigated data from a previously conducted GWAS on BC survival for enriched pathways by different enrichment analysis tools using the two main annotation databases Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). The goal was to identify the functional categories (GO terms and KEGG pathways) that are consistently overrepresented in a statistically significant way in the list of genes generated from the single nucleotide polymorphism (SNP) data. The SNPs with allelic p-value cut-offs 0.005 and 0.01 were annotated to the genes by excluding or including a 20 kb up-and down-stream sequence of the genes and analyzed by six different tools. We identified eleven consistently enriched categories, the most significant ones relating to cell adhesion and calcium ion binding. Moreover, we investigated the similarity between our GWAS and the enrichment analyses of twelve published gene expression signatures for breast cancer prognosis. Five of them were commonly used and commercially available, five were based on different aspects of metastasis formation and two were developed from meta-analyses of published prognostic signatures. This comparison revealed similarities between our GWAS data and the general and the specific brain metastasis gene signatures as well as the Oncotype DX signature. As metastasis formation is a strong indicator of a patient's prognosis, this result reflects the survival aspect of the conducted GWAS and supports cell adhesion and calcium signaling as important pathways in cancer progression.
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| 4. |
- Abbas, Sascha, et al.
(författare)
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Dietary intake of vitamin D and calcium and breast cancer risk in the European prospective investigation into cancer and nutrition
- 2013
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Ingår i: Nutrition and Cancer. - : Taylor & Francis. - 0163-5581 .- 1532-7914. ; 65:2, s. 178-187
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Tidskriftsartikel (refereegranskat)abstract
- Studies assessing the effects of vitamin D or calcium intake on breast cancer risk have been inconclusive. Furthermore, few studies have evaluated them jointly. This study is the largest so far examining the association of dietary vitamin D and calcium intake with breast cancer risk in the European Prospective Investigation into Cancer and Nutrition. During a mean follow-up of 8.8 yr, 7760 incident invasive breast cancer cases were identified among 319,985 women. Multivariable Cox proportional hazards regression was used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for pre- and postmenopausal breast cancer risk. Comparing the highest with the lowest quintile of vitamin D intake, HR and 95% CI were 1.07 (0.87-1.32) and 1.02 (0.90-1.16) for pre- and postmenopausal women, respectively. The corresponding HR and 95% CIs for calcium intake were 0.98 (0.80-1.19) and 0.90 (0.79-1.02), respectively. For calcium intake in postmenopausal women, the test for trend was borderline statistically significant (P(trend) = 0.05). There was no significant interaction between vitamin D and calcium intake and cancer risk (P(interaction) = 0.57 and 0.22 in pre- and postmenopausal women, respectively). In this large prospective cohort, we found no evidence for an association between dietary vitamin D or calcium intake and breast cancer risk.
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| 5. |
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| 6. |
- Arslan, Alan A., et al.
(författare)
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Circulating Estrogen Metabolites and Risk of Breast Cancer in Postmenopausal Women
- 2014
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Ingår i: Cancer Epidemiology, Biomarkers and Prevention. - 1055-9965 .- 1538-7755. ; 23:7, s. 1290-1297
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Tidskriftsartikel (refereegranskat)abstract
- Background: It has been hypothesized that predominance of the 2-hydroxylation estrogen metabolism pathway over the 16 alpha-hydroxylation pathway may be inversely associated with breast cancer risk. Methods: We examined the associations of invasive breast cancer risk with circulating 2-hydroxyestrone (2-OHE1), 16 alpha-hydroxyestrone (16 alpha-OHE1), and the 2-OHE1: 16 alpha-OHE1 ratio in a case-control study of postmenopausal women nested within two prospective cohorts: the New York University Women's Health Study (NYUWHS) and the Northern Sweden Mammary Screening Cohort (NSMSC), with adjustment for circulating levels of estrone, and additional analyses by tumor estrogen receptor (ER) status. Levels of 2-OHE1 and 16 alpha-OHE1 were measured using ESTRAMET 2/16 assay in stored serum or plasma samples from 499 incident breast cancer cases and 499 controls, who were matched on cohort, age, and date of blood donation. Results: Overall, no significant associations were observed between breast cancer risk and circulating levels of 2-OHE1, 16 alpha-OHE1, or their ratio in either cohort and in combined analyses. For 2-OHE1, there was evidence of heterogeneity by ER status in models adjusting for estrone (P <= 0.03). We observed a protective association of 2-OHE1 with ER + breast cancer [multivariate-adjusted OR for a doubling of 2-OHE1, 0.67 (95% confidence interval [CI], 0.48-0.94; P = 0.02)]. Conclusions: In this study, higher levels of 2-OHE1 were associated with reduced risk of ER + breast cancer in postmenopausal women after adjustment for circulating estrone. Impact: These results suggest that taking into account the levels of parent estrogens and ER status is important in studies of estrogen metabolites and breast cancer.
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| 7. |
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| 8. |
- Barekati, Zeinab, et al.
(författare)
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Methylation profile of TP53 regulatory pathway and mtDNA alterations in breast cancer patients lacking TP53 mutations
- 2010
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Ingår i: Human Molecular Genetics. - : Oxford Journals. - 0964-6906 .- 1460-2083. ; 19:15, s. 2936-2946
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Tidskriftsartikel (refereegranskat)abstract
- The present study investigated promoter hypermethylation of TP53 regulatory pathways providing a potential link between epigenetic changes and mitochondrial DNA (mtDNA) alterations in breast cancer patients lacking a TP53 mutation. The possibility of using the cancer-specific alterations in serum samples as a blood-based test was also explored. Triple-matched samples (cancerous tissues, matched adjacent normal tissues and serum samples) from breast cancer patients were screened for TP53 mutations, and the promoter methylation profile of P14(ARF), MDM2, TP53 and PTEN genes was analyzed as well as mtDNA alterations, including D-loop mutations and mtDNA content. In the studied cohort, no mutation was found in TP53 (DNA-binding domain). Comparison of P14(ARF) and PTEN methylation patterns showed significant hypermethylation levels in tumor tissues (P < 0.05 and <0.01, respectively) whereas the TP53 tumor suppressor gene was not hypermethylated (P < 0.511). The proportion of PTEN methylation was significantly higher in serum than in the normal tissues and it has a significant correlation to tumor tissues (P < 0.05). mtDNA analysis revealed 36.36% somatic and 90.91% germline mutations in the D-loop region and also significant mtDNA depletion in tumor tissues (P < 0.01). In addition, the mtDNA content in matched serum was significantly lower than in the normal tissues (P < 0.05). These data can provide an insight into the management of a therapeutic approach based on the reversal of epigenetic silencing of the crucial genes involved in regulatory pathways of the tumor suppressor TP53. Additionally, release of significant aberrant methylated PTEN in matched serum samples might represent a promising biomarker for breast cancer.
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| 9. |
- Barekati, Zeinab, et al.
(författare)
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Methylation signature of lymph node metastases in breast cancer patients
- 2012
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Ingår i: BMC Cancer. - : BioMed Central. - 1471-2407 .- 1471-2407. ; 12, s. 244-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Invasion and metastasis are two important hallmarks of malignant tumors caused by complex genetic and epigenetic alterations. The present study investigated the contribution of aberrant methylation profiles of cancer related genes, APC, BIN1, BMP6, BRCA1, CST6, ESR-b, GSTP1, P14 (ARF), P16 (CDKN2A), P21 (CDKN1A), PTEN, and TIMP3, in the matched axillary lymph node metastasis in comparison to the primary tumor tissue and the adjacent normal tissue from the same breast cancer patients to identify the potential of candidate genes methylation as metastatic markers. Methods: The quantitative methylation analysis was performed using the SEQUENOM's EpiTYPER (TM) assay which relies on matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Results: The quantitative DNA methylation analysis of the candidate genes showed higher methylation proportion in the primary tumor tissue than that of the matched normal tissue and the differences were significant for the APC, BIN1, BMP6, BRCA1, CST6, ESR-b, P16, PTEN and TIMP3 promoter regions (P<0.05). Among those candidate methylated genes, APC, BMP6, BRCA1 and P16 displayed higher methylation proportion in the matched lymph node metastasis than that found in the normal tissue (P<0.05). The pathway analysis revealed that BMP6, BRCA1 and P16 have a role in prevention of neoplasm metastasis. Conclusions: The results of the present study showed methylation heterogeneity between primary tumors and metastatic lesion. The contribution of aberrant methylation alterations of BMP6, BRCA1 and P16 genes in lymph node metastasis might provide a further clue to establish useful biomarkers for screening metastasis.
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| 10. |
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