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- Bartkova, Jirina, et al.
(författare)
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Aberrations of the MRE11-RAD50-NBS1 DNA damage sensor complex in human breast cancer : MRE11 as a candidate familial cancer-predisposing gene
- 2008
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Ingår i: Molecular Oncology. - : Wiley. - 1574-7891. ; 2:4, s. 296-316
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Tidskriftsartikel (refereegranskat)abstract
- The MRE11, RAD50, and NBS1 genes encode proteins of the MRE11-RAD50-NBS1 (MRN) complex critical for proper maintenance of genomic integrity and tumour suppression; however, the extent and impact of their cancer-predisposing defects, and potential clinical value remain to be determined. Here, we report that among a large series of approximately 1000 breast carcinomas, around 3%, 7% and 10% tumours showed aberrantly reduced protein expression for RAD50, MRE11 and NBS1, respectively. Such defects were more frequent among the ER/PR/ERBB2 triple-negative and higher-grade tumours, among familial (especially BRCA1/BRCA2-associated) rather than sporadic cases, and the NBS1 defects correlated with shorter patients' survival. The BRCA1-associated and ER/PR/ERBB2 triple-negative tumours also showed high incidence of constitutively active DNA damage signalling (gamma H2AX) and p53 aberrations. Sequencing the RAD50, MRE11 and NBS1 genes of 8 patients from non-BRCA1/2 breast cancer families whose tumours showed concomitant reduction/loss of all three MRN-complex proteins revealed two germline mutations in MRE11: a missense mutation R202G and a truncating mutation R633STOP (R633X). Gene transfer and protein analysis of cell culture models with mutant MRE11 implicated various destabilization patterns among the MRN complex proteins including NBS1, the abundance of which was restored by re-expression of wild-type MRE11. We propose that germline mutations qualify MRE11 as a novel candidate breast cancer susceptibility gene in a subset of non-BRCA1/2 families. Our data have implications for the concept of the DNA damage response as an intrinsic anti-cancer barrier, various components of which become inactivated during cancer progression and also represent the bulk of breast cancer susceptibility genes discovered to date.
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| 2. |
- Fagerholm, Rainer, et al.
(författare)
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NAD(P)H:quinone oxidoreductase 1 NQO1*2 genotype (P187S) is a strong prognostic and predictive factor in breast cancer
- 2008
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 40:7, s. 844-53
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Tidskriftsartikel (refereegranskat)abstract
- NQO1 guards against oxidative stress and carcinogenesis and stabilizes p53. We find that a homozygous common missense variant (NQO1(*)2, rs1800566(T), NM_000903.2:c.558C>T) that disables NQO1 strongly predicts poor survival among two independent series of women with breast cancer (P = 0.002, N = 1,005; P = 0.005, N = 1,162), an effect particularly evident after anthracycline-based adjuvant chemotherapy with epirubicin (P = 7.52 x 10(-6)) and in p53-aberrant tumors (P = 6.15 x 10(-5)). Survival after metastasis was reduced among NQO1(*)2 homozygotes, further implicating NQO1 deficiency in cancer progression and treatment resistance. Consistently, response to epirubicin was impaired in NQO1(*)2-homozygous breast carcinoma cells in vitro, reflecting both p53-linked and p53-independent roles of NQO1. We propose a model of defective anthracycline response in NQO1-deficient breast tumors, along with increased genomic instability promoted by elevated reactive oxygen species (ROS), and suggest that the NQO1 genotype is a prognostic and predictive marker for breast cancer.
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| 3. |
- Heikkinen, Tuomas, et al.
(författare)
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Variants on the promoter region of PTEN affect breast cancer progression and patient survival
- 2011
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Ingår i: Breast Cancer Research. - : Springer Science and Business Media LLC. - 1465-5411 .- 1465-542X. ; 13:6, s. R130-
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUTION:The PTEN gene, a regulator of the phosphatidylinositol-3-kinase (PI3K)/Akt oncogenic pathway, is mutated in various cancers and its expression has been associated with tumor progression in a dose-dependent fashion. We investigated the effect of germline variation in the promoter region of the PTEN gene on clinical characteristics and survival in breast cancer.METHODS:We screened the promoter region of the PTEN gene for germline variation in 330 familial breast cancer cases and further determined the genotypes of three detected PTEN promoter polymorphisms -903GA, -975GC, and -1026CA in a total of 2,412 breast cancer patients to evaluate the effects of the variants on tumor characteristics and disease outcome. We compared the gene expression profiles in breast cancers of 10 variant carriers and 10 matched non-carriers and performed further survival analyses based on the differentially expressed genes.RESULTS: All three promoter variants associated with worse prognosis. The Cox's regression hazard ratio for 10-year breast cancer specific survival in multivariate analysis was 2.01 (95% CI 1.17 to 3.46) P = 0.0119, and for 5-year breast cancer death or distant metastasis free survival 1.79 (95% CI 1.03 to 3.11) P = 0.0381 for the variant carriers, indicating PTEN promoter variants as an independent prognostic factor. The breast tumors from the promoter variant carriers exhibited a similar gene expression signature of 160 differentially expressed genes compared to matched non-carrier tumors. The signature further stratified patients into two groups with different recurrence free survival in independent breast cancer gene expression data sets.CONCLUSIONS:Inherited variation in the PTEN promoter region affects the tumor progression and gene expression profile in breast cancer. Further studies are warranted to establish PTEN promoter variants as clinical markers for prognosis in breast cancer.
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| 5. |
- Tommiska, Johanna, et al.
(författare)
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ATM variants and cancer risk in breast cancer patients from Southern Finland
- 2006
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Ingår i: BMC Cancer. - : Springer Science and Business Media LLC. - 1471-2407. ; 6, s. 209-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Individuals heterozygous for germline ATM mutations have been reported to have an increased risk for breast cancer but the role for ATM genetic variants for breast cancer risk has remained unclear. Recently, a common ATM variant, ATMivs38 - 8T> C in cis with the ATMex39 5557G> A ( D1853N) variant, was suggested to associate with bilateral breast cancer among familial breast cancer patients from Northern Finland. We have here evaluated the 5557G> A and ivs38- 8T> C variants in an extensive case-control association analysis. We also aimed to investigate whether there are other ATM mutations or variants contributing to breast cancer risk in our population. Methods: Two common ATM variants, 5557G> A and ivs38- 8T> C, previously suggested to associate with bilateral breast cancer, were genotyped in an extensive set of 786 familial and 884 unselected breast cancer cases as well as 708 healthy controls. We also screened the entire coding region and exon-intron boundaries of the ATM gene in 47 familial breast cancer patients and constructed haplotypes of the patients. The identified variants were also evaluated for increased breast cancer risk among additional breast cancer cases and controls. Results: Neither of the two common variants, 5557G> A and ivs38- 8T> C, nor any haplotype containing them, was significantly associated with breast cancer risk, bilateral breast cancer or multiple primary cancers in any of the patient groups or subgoups. Three rare missense alterations and one intronic change were each found in only one patient of over 250 familial patients studied and not among controls. The fourth missense alteration studied further was found with closely similar frequencies in over 600 familial cases and controls. Conclusion: Altogether, our results suggest very minor effect, if any, of ATM genetic variants on familial breast cancer in Southern Finland. Our results do not support association of the 5557G> A or ivs38- 8T> C variant with increased breast cancer risk or with bilateral breast cancer.
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