| 41. |
- Rozenblum, E, et al.
(författare)
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A genomic map of a 6-Mb region at 13q21-q22 implicated in cancer development: identification and characterization of candidate genes
- 2002
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Ingår i: Human Genetics. - : Springer Science and Business Media LLC. - 1432-1203 .- 0340-6717. ; 110:2, s. 111-121
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Tidskriftsartikel (refereegranskat)abstract
- Chromosomal region 13q21-q22 harbors a putative breast cancer susceptibility gene and has been implicated as a common site for somatic deletions in a variety of malignant tumors. We have built a complete physical clone contig for a region between D13S1308 and AFM220YE9 based on 18 yeast artificial chromosome and 81 bacterial artificial chromosome (BAC) clones linked together by 22 genetic markers and 61 other sequence tagged sites. Combining data from 47 sequenced BACs (as of June 2001), we have assembled in silico an integrated 5.7-Mb genomic map with 90% sequence coverage. This area contains eight known genes, two hypothetical proteins, 24 additional Unigene clusters, and approximately 100 predicted genes and exons. We have determined the cDNA and genomic sequence, and tissue expression profiles for the KIAA1008 protein (homologous to the yeast mitotic control protein dis3+), KLF12 (AP-2 repressor), progesterone induced blocking factor 1, zinc finger transcription factor KLF5, and LIM domain only-7, and for the hypothetical proteins FLJ22624 and FLJ21869. Mutation screening of the five known genes in 19 breast cancer families has revealed numerous polymorphisms, but no deleterious mutations. These data provide a basis and resources for further analyses of this chromosomal region in the development of cancer.
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| 42. |
- Saal, Lao, et al.
(författare)
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Bioarray software environment: a platform for comprehensive management and analysis of microarray data
- 2002
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Ingår i: Genome Biology. - : Springer Science and Business Media LLC. - 1474-7596 .- 1465-6906. ; 3:8, s. 1-2002
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Tidskriftsartikel (refereegranskat)abstract
- The microarray technique requires the organization and analysis of vast amounts of data. These data include information about the samples hybridized, the hybridization images and their extracted data matrices, and information about the physical array, the features and reporter molecules. We present a web-based customizable bioinformatics solution called BioArray Software Environment (BASE) for the management and analysis of all areas of microarray experimentation. All software necessary to run a local server is available for free and the source code may be downloaded from http://base.thep.lu.se.
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| 43. |
- Salahshor, Sima, et al.
(författare)
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Low frequency of E-cadherin alterations in familial breast cancer
- 2001
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Ingår i: Breast Cancer Research. - : Springer Science and Business Media LLC. - 1465-5411 .- 1465-542X. ; 3:3, s. 199-207
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Tidskriftsartikel (refereegranskat)abstract
- In order to explore the possible role of E-cadherin in familial cancer, 19 familial breast cancer patients, whose tumours demonstrated loss of heterozygosity (LOH) at the E-cadherin locus, were screened for germline mutations. No pathogenic germline alterations were detected in these individuals. However, a somatic mutation was found (49-2A-->C) in one of the tumours. This tumour showed a pattern of both ductal and lobular histology. Another 10 families with cases of breast, gastric and colon cancer were also screened for germline mutations, and no mutations were found. A missense mutation in exon 12 of E-cadherin (1774G-->A; Ala592Thr) was previously found in one family with diffuse gastric cancer, and colon and breast cancer. An allelic association study was performed to determine whether the Ala592Thr alteration predisposes to breast cancer. In total, we studied 484 familial breast cancer patients, 614 sporadic breast cancer patients and 497 control individuals. The frequencies of this alteration were similar in these groups. However, a correlation between the Ala592Thr alteration and ductal comedo-type tumour was seen. These results, together with previously reported studies, indicate that germline mutations and, more commonly, somatic mutations in E-cadherin may have an influence on the behaviour of the tumours, rather than predispose to breast cancer.
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| 44. |
- Staff, S., et al.
(författare)
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Frequent somatic loss of BRCA1 in breast tumours from BRCA2 germ-line mutation carriers and vice versa
- 2001
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Ingår i: British Journal of Cancer. - : Springer Science and Business Media LLC. - 1532-1827 .- 0007-0920. ; 85:8, s. 1201-1205
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Tidskriftsartikel (refereegranskat)abstract
- Breast cancer susceptibility genes BRCA1 and BRCA2 are tumour suppressor genes the alleles of which have to be inactivated before tumour development occurs. Hereditary breast cancers linked to germ-line mutations of BRCA1 and BRCA2 genes almost invariably show allelic imbalance (Al) at the respective loci. BRCA1 and BRCA2 are believed to take part in a common pathway in maintenance of genomic integrity in cells. We carried out Al and fluorescence in situ hybridization (FISH) analyses of BRCA2 in breast tumours from germline BRCA1 mutation carriers and vice versa. For comparison, 14 sporadic breast tumours were also studied. 8 of the 11 (73%) informative BRCA1 mutation tumours showed Al at the BRCA2 focus. 53% of these tumours showed a copy number loss of the BRCA2 gene by FISH. 5 of the 6 (83%) informative BRCA2 mutation tumours showed Al at the BRCA1 locus. Half of the tumours (4/8) showed a physical deletion of the BRCA1 gene by FISH. Combined allelic loss of both BRCA1 and BRCA2 gene was seen in 12 of the 17 (71%) informative hereditary tumours, whereas copy number losses of both BRCA genes was seen in only 4/14 (29%) sporadic control tumours studied by FISH. In conclusion, the high prevalence of Al at BRCA1 in BRCA2 mutation tumours and vice versa suggests that somatic events occurring at the other breast cancer susceptibility gene locus may be selected in the cancer development. The mechanism resulting in Al at these loci seems more complex than a physical deletion.
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| 45. |
- Syrjakoski, K, et al.
(författare)
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BRCA2 mutations in 154 Finnish male breast cancer patients
- 2004
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Ingår i: Neoplasia. - : Elsevier BV. - 1522-8002 .- 1476-5586. ; 6:5, s. 541-545
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Tidskriftsartikel (refereegranskat)abstract
- The etiology and pathogenesis of male breast cancer (MBC) are poorly known. This is due to the fact that the disease is rare, and large-scale genetic epidemiologic studies have been difficult to carry out. Here, we studied the frequency of eight recurrent Finnish BRCA2 founder mutations in a large cohort of 154 MBC patients (65% diagnosed in Finland from 1967 to 1996). Founder mutations were detected in 10 patients (6.5%), eight of whom carried the 9346(-2) A>G mutation. Two novel mutations (4075 delGT and 5808 del5) were discovered in a screening of the entire BRCA2 coding region in 34 samples. However, these mutations were not found in the rest of the 120 patients studied. Patients with positive family history of breast and/or ovarian cancer were often BRCA2 mutation carriers (44%), whereas those with no family history showed a low frequency of involvement (3.6%; P < .0001). Finally, we found only one Finnish MBC patient with 999 del5, the most common founder mutation in Finnish female breast cancer (FBC) patients, and one that explains most of the hereditary FBC and MBC cases in Iceland. The variation in BRCA2 mutation spectrum between Finnish MBC patients and FBC patients in Finland and breast cancer patients in Iceland suggests that modifying genetic and environmental factors may significantly influence the penetrance of MBC and FBC in individuals carrying germline BRCA2 mutations in some populations.
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| 46. |
- Thomassen, M, et al.
(författare)
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Loss of heterozygosity at BRCA2 in a ductal carcinoma in situ and three invasive breast carcinomas in a family with a germline BRCA2 mutation
- 2004
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Ingår i: Breast Cancer Research and Treatment. - : Springer Science and Business Media LLC. - 1573-7217 .- 0167-6806. ; 87:3, s. 273-276
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Tidskriftsartikel (refereegranskat)abstract
- We have examined a family with a germline BRCA2 mutation in three cases of invasive breast cancer and one case of ductal carcinoma in situ ( DCIS). Loss of heterozygosity (LOH) has been demonstrated at the BRCA2 locus in all cases. This result may suggest that the germline mutation in BRCA2 is the initiating step of DCIS and support the theory that DCIS is a precursor of invasive breast carcinoma in hereditary breast cancer.
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| 47. |
- Thompson, D, et al.
(författare)
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Cancer Incidence in BRCA1 mutation carriers
- 2002
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Ingår i: Journal of the National Cancer Institute. - : Oxford University Press (OUP). - 1460-2105 .- 0027-8874. ; 94:18, s. 1358-1365
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Tidskriftsartikel (refereegranskat)abstract
- Background: Germline BRCA1 mutations confer a substantial lifetime risk of breast and ovarian cancer, but whether cancer at other sites is increased is less clear. To evaluate the risks of other cancers in BRCA1 mutation carriers, we conducted a cohort study of 11 847 individuals from 699 families segregating a BRCA1 mutation that were ascertained in 30 centers across Europe and North America. Methods: The observed cancer incidence was compared with the expected cancer incidence based on population cancer rates. Relative risks (RRs) of each cancer type in BRCA1 carriers relative to risks for the general population were estimated by weighting individuals according to their estimated probability of being a mutation carrier. All statistical tests were two-sided. Results: BRCA1 mutation carriers were at a statistically significantly increased risk for several cancers, including pancreatic cancer (RR = 2.26, 95% confidence interval [CI] = 1.26 to 4.06, P = .004) and cancer of the uterine body and cervix (uterine body RR = 2.65, 95% CI = 1.69 to 4.16, P<.001; cervix RR = 3.72, 95% CI = 2.26 to 6.10, P<.001). There was some evidence of an elevated risk of prostate cancer in mutation carriers younger than 65 years old (RR = 1.82, 95% CI = 1.01 to 3.29, P = .05) but not in those 65 years old or older (RR = 0.84, 95% CI = 0.53 to 1.33, P = .45). Overall, increases in the risk for cancer at sites other than the breast or ovary were small and evident in women (RR = 2.30, 95% CI = 1.93 to 2.75, P = .001) but not in men (RR = 0.95, 95% CI = 0.81 to 1.12, P = .58). Conclusions: In carriers of BRCA1 mutations, the overall increased risk of cancer at sites other than breast and ovary is small and is observed in women but generally not in men. BRCA1 mutations may confer increased risks of other abdominal cancers in women and increased risks of pancreatic cancer in men and women.
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| 48. |
- Thompson, Deborah, et al.
(författare)
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Variation in BRCA1 cancer risks by mutation position
- 2002
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Ingår i: Cancer Epidemiology Biomarkers & Prevention. - 1538-7755. ; 11:4, s. 329-336
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Tidskriftsartikel (refereegranskat)abstract
- Previous studies have reported variation in BRCA1 breast and ovarian cancer risks with mutation position, suggesting that mutations toward the 3' end of the gene are associated with lower ovarian cancer risks. We evaluated the evidence for genotype-phenotype correlations in 356 families with protein-truncating BRCA1 mutations. In contrast to previous reports, the ovarian:breast cancer ratio associated with mutations in a central region of the gene (nucleotides 2401–4190) was significantly higher than for other mutations [odds ratio, 1.70 (P = 0.017) compared with nucleotides 1–2400; odds ratio, 1.89 (P = 0.02) compared with nucleotides 4191–end]. The risks of breast and ovarian cancer conferred by mutations in different regions of the gene were estimated separately by conditional maximum likelihood. According to the best fitting model, the breast cancer risk associated with mutations in the central region was found to be significantly lower than for other mutations (relative risk, 0.71; 95% confidence interval, 0.58–0.86; P = 0.0002), whereas the ovarian cancer risk associated with mutations 3' to nucleotide 4191 was significantly reduced relative to the rest of the gene (relative risk, 0.81; 95% confidence interval, 0.66–1.00; P = 0.044). The cancer risks associated with missense mutations in the RING domain in exon 5 appear to be similar to those associated with protein-truncating mutations toward the 3' end of BRCA1, based on nine additional families.
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| 49. |
- Vallon-Christersson, J, et al.
(författare)
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Functional analysis of BRCA1 C-terminal missense mutations identified in breast and ovarian cancer families
- 2001
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Ingår i: Human Molecular Genetics. - : Oxford University Press (OUP). - 0964-6906 .- 1460-2083. ; 10:4, s. 60-353
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Tidskriftsartikel (refereegranskat)abstract
- Germline mutations in the breast and ovarian cancer susceptibility gene BRCA1 are responsible for the majority of cases involving hereditary breast and ovarian cancer. Whereas all truncating mutations are considered as functionally deleterious, most of the missense variants identified to date cannot be readily distinguished as either disease-associated mutations or benign polymorphisms. The C-terminal domain of BRCA1 displays an intrinsic transactivation activity, and mutations linked to disease predisposition have been shown to confer loss of such activity in yeast and mammalian cells. In an attempt to clarify the functional importance of the BRCA1 C-terminus as a transcription activator in cancer predisposition, we have characterized the effect of C-terminal germline variants identified in Scandinavian breast and ovarian cancer families. Missense variants A1669S, C1697R, R1699W, R1699Q, A1708E, S1715R and G1738E and a truncating mutation, W1837X, were characterized using yeast- and mammalian-based transcription assays. In addition, four additional missense variants (V1665M, D1692N, S1715N and D1733G) and one in-frame deletion (V1688del) were included in the study. Our findings demonstrate that transactivation activity may reflect a tumor-suppressing function of BRCA1 and further support the role of BRCA1 missense mutations in disease predisposition. We also report a discrepancy between results from yeast- and mammalian-based assays, indicating that it may not be possible to unambiguously characterize variants with the yeast assay alone. We show that transcription-based assays can aid in the characterization of deleterious mutations in the C-terminal part of BRCA1 and may form the basis of a functional assay.
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| 50. |
- Worley, T, et al.
(författare)
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A naturally occurring allele of BRCA1 coding for a temperature-sensitive mutant protein
- 2002
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Ingår i: Cancer Biology & Therapy. - 1538-4047. ; 1:5, s. 497-501
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Tidskriftsartikel (refereegranskat)abstract
- Recent evidence suggests that the breast and ovarian cancer susceptibility gene product BRCA1 is involved in at least two fundamental cellular processes: transcriptional regulation and DNA repair. However, the mechanism of action of BRCA1 in either of these processes is still unknown. Here, we report the characterization of a disease-predisposing allele of BRCA1, identified in a family with several cases of ovarian cancer, coding for a protein that displays temperature-sensitive activity in transcriptional activation. The mutant protein differs from the wild type protein at a single amino acid, R1 699W that occurs in a region at the N-terminal BRCT domain that is highly conserved among BRCA1 homologs. When the C-terminus of the mutant protein (aa 1560-1863) was fused to a heterologous GAL4 DNA-binding domain and expressed in yeast or mammalian cells, it was able to activate transcription of a reporter gene to levels observed for wild type BRCA1 at the permissive temperature (30degreesC) but exhibited significantly less transcription activity at the restrictive temperature (37degreesC or 39degreesC). Our results indicate that the transcriptional activity of the R1699W mutant can be modulated as a function of temperature and provide a novel experimental approach which can be utilized to dissect the molecular mechanism(s) of BRCA1 in processes related to transcription.
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