| 11. |
- Ju, Young Seok, et al.
(författare)
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Frequent somatic transfer of mitochondrial DNA into the nuclear genome of human cancer cells.
- 2015
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Ingår i: Genome Research. - : Cold Spring Harbor Laboratory. - 1549-5469 .- 1088-9051. ; 25:6, s. 814-824
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Tidskriftsartikel (refereegranskat)abstract
- Mitochondrial genomes are separated from the nuclear genome for most of the cell cycle by the nuclear double membrane, intervening cytoplasm, and the mitochondrial double membrane. Despite these physical barriers, we show that somatically acquired mitochondrial-nuclear genome fusion sequences are present in cancer cells. Most occur in conjunction with intranuclear genomic rearrangements, and the features of the fusion fragments indicate that nonhomologous end joining and/or replication-dependent DNA double-strand break repair are the dominant mechanisms involved. Remarkably, mitochondrial-nuclear genome fusions occur at a similar rate per base pair of DNA as interchromosomal nuclear rearrangements, indicating the presence of a high frequency of contact between mitochondrial and nuclear DNA in some somatic cells. Transmission of mitochondrial DNA to the nuclear genome occurs in neoplastically transformed cells, but we do not exclude the possibility that some mitochondrial-nuclear DNA fusions observed in cancer occurred years earlier in normal somatic cells.
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| 12. |
- Fletcher, Olivia, et al.
(författare)
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Family history, genetic testing, and clinical risk prediction : pooled analysis of CHEK2 1100delC in 1,828 bilateral breast cancers and 7,030 controls
- 2009
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Ingår i: Cancer Epidemiology, Biomarkers and Prevention. - 1055-9965 .- 1538-7755. ; 18:1, s. 230-4
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Tidskriftsartikel (refereegranskat)abstract
- If breast cancers arise independently in each breast the odds ratio (OR) for bilateral breast cancer for carriers of CHEK2 1100delC should be approximately 5.5, the square of the reported OR for a first primary (OR, 2.34). In the subset of bilateral cases with one or more affected relatives, the predicted carrier OR should be approximately 9. We have tested these predictions in a pooled set of 1,828 cases with 2 primaries and 7,030 controls from 8 studies. The second primary OR for CHEK2 1100delC carriers was 6.43 (95% confidence interval, 4.33-9.56; P < 0.0001), significantly greater than the published estimate for a first primary (P < 0.001) but consistent with its square. The predicted increase in carrier OR with increasing numbers of affected relatives was seen using bilateral cases from the UK (P(trend) = 0.0003) and Finland (P(trend) = 0.37), although not using those from the Netherlands and Russia (P = 0.001 for heterogeneity between countries). Based on a standard genetic model, we predict lifetime risks for CHEK2 1100delC carrier and noncarrier daughters of bilateral breast cancer cases of 37% and 18%, respectively. Our results imply that clinical management of the daughter of a woman with bilateral breast cancer should depend on her CHEK2 1100delC carrier status. This and other moderate penetrance breast cancer susceptibility alleles, together with family history data, will thus identify increasing numbers of women at potentially very high risk. Before such predictions are accepted by clinical geneticists, however, further population-based evidence is needed on the effect of CHEK2 1100delC and other moderate penetrance alleles in women with a family history of breast cancer.
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| 13. |
- Kok, Marleen, et al.
(författare)
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PKA-induced phosphorylation of ER alpha at serine 305 and high PAK1 levels is associated with sensitivity to tamoxifen in ER-positive breast cancer
- 2011
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Ingår i: Breast Cancer Research and Treatment. - : Springer Science and Business Media LLC. - 1573-7217 .- 0167-6806. ; 125:1, s. 1-12
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Tidskriftsartikel (refereegranskat)abstract
- Phosphorylation of estrogen receptor alpha at serine 305 (ER alpha S305-P) by protein kinase A (PKA) or p21-activated kinase 1 (PAK1) has experimentally been associated with tamoxifen sensitivity. Here, we investigated the clinical application of this knowledge to predict tamoxifen resistance in ER-positive breast cancer patients. Using immunohistochemistry, a score including PAK1 and co-expression of PKA and ER alpha S305-P (PKA/ER alpha S305-P) was developed on a training set consisting of 103 patients treated with tamoxifen for metastatic disease, and validated on 231 patients randomized between adjuvant tamoxifen or no treatment. In the training set, PAK1 levels were associated with tumor progression after tamoxifen (HR 1.57, 95% CI 0.99-2.48), as was co-expression of PKA and ER alpha S305-P (HR 2.00, 95% CI 1.14-3.52). In the validation set, a significant tamoxifen benefit was found among the 73% patients negative for PAK1 and PKA/ER alpha S305-P (HR 0.54, 95% CI 0.34-0.87), while others (27%) were likely to have no benefit from tamoxifen (HR 0.88, 95% 0.42-1.82). The test for interaction showed a significant difference in recurrence-free survival between groups defined by PAK1 and PKA/ER alpha S305-P (P = 0.037). Elevated PAK1 and PKA/ER alpha S305-P appeared to influence tamoxifen sensitivity. Both PAK1 and PKA/ER alpha S305-P levels were associated with sensitivity to tamoxifen in breast tumors and the combination of these variables should be considered in predicting tamoxifen benefit.
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| 14. |
- Schmidt, Marjanka K, et al.
(författare)
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Do MDM2 SNP309 and TP53 R72P interact in breast cancer susceptibility? A large pooled series from the breast cancer association consortium
- 2007
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Ingår i: Cancer Research. - 0008-5472 .- 1538-7445. ; 67:19, s. 9584-9590
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Tidskriftsartikel (refereegranskat)abstract
- Association studies in large series of breast cancer patients can be used to identify single-nucleotide polymorphisms (SNP) contributing to breast cancer susceptibility. Previous studies have suggested associations between variants in TP53 (R72P) and MDM2 (SNP309) and cancer risk. Data from molecular studies suggest a functional interaction between these genes. We therefore investigated the effect of TP53 R72P and MDM2 SNP309 on breast cancer risk and age at onset of breast cancer in a pooled series of 5,191 cases and 3,834 controls from the Breast Cancer Association Consortium (BCAC). Breast cancer risk was not found to be associated with the combined variant alleles [odds ratio (OR), 1.00; 95% confidence interval (95% CI), 0.81–1.23]. Estimated ORs were 1.01 (95% CI, 0.93–1.09) per MDM2 SNP309 allele and 0.98 (95% CI, 0.91–1.04) for TP53 R72P. Although we did find evidence for a 4-year earlier age at onset for carriers of both variant alleles in one of the breast cancer patient series of the BCAC (the German series), we were not able to confirm this effect in the pooled analysis. Even so, carriers of both variant alleles did not have different risk estimates for bilateral or estrogen receptor–positive breast cancer. In conclusion, in this large collaborative study, we did not find an association of MDM2 SNP309 and TP53 R72P, separately or in interaction, with breast cancer. This suggests that any effect of these two variants would be very small and possibly confined to subgroups that were not assessed in our present study.
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