NCI CANCERLIT^® Search: BRCA1 Gene - September 2001

Last Modified: November 1, 2001

Psychological impact of receiving a BRCA1/BRCA2 test result.
Reading between the lines: direct-to-consumer advertising of genetic testing.
Profiling of protein kinases in the neoplastic transformation of human ovarian surface epithelium.
Frequently occurring germ-line mutations of the BRCA1 gene in ovarian cancer families from Russia.
Diagnostic strategy for analytical scanning of BRCA1 gene by fluorescence-assisted mismatch analysis using large, bifluorescently labeled amplicons.
BRCA1 mediates ligand-independent transcriptional repression of the estrogen receptor.
Insurance policies for prophylactic surgery: to cover or not to cover?
Direct removal in the mouse of a floxed neo gene from a three-loxP conditional knockout allele by two novel approaches.
Functional analysis of CpG methylation in the BRCA1 promoter region.
The incidence of breast cancer from screening women according to predicted family history risk: Does annual clinical examination add to mammography?

CancerMail from the National Cancer Institute

1
UI - 21319740
AU - Lodder L; Frets PG; Trijsburg RW; Meijers-Heijboer EJ; Klijn JG; Duivenvoorden HJ; Tibben A; Wagner A; van der Meer CA; van den Ouweland AM; Niermeijer MF
TI - Psychological impact of receiving a BRCA1/BRCA2 test result.
SO - Am J Med Genet 2001 Jan 1;98(1):15-24
AD - Department of Medical Psychology and Psychotherapy, Erasmus University Rotterdam/Netherlands Institute for Health Sciences.
Mutation analysis for autosomal dominant hereditary breast/ovarian cancer genes (BRCA1/BRCA2) became an important technique for women at risk of carrying these mutations. Healthy female mutation carriers have a high lifetime risk for breast and/or ovarian cancer and may opt for frequent breast and ovary surveillance or prophylactic surgery (mastectomy and/or oophorectomy). Psychological distress was assessed in 78 healthy women at risk of having inherited a BRCA1/BRCA2 mutation opting for genetic testing and 56 partners several weeks prior to ("pre-test") and after ("post-test") learning about their DNA test result. Twenty-five women were found to be mutation carriers, and 53 were non-mutation carriers. One goal of the study was to identify individuals at risk for high distress in the weeks following disclosure of the test result. Interview transcripts were used to give a fuller picture of pre- and post-test distress. High post-test anxiety was reported by 20% of the mutation carrier women and by 35% of their partners. Eleven percent of women without the mutation and 13% of their partners reported high post-test anxiety levels. High post-test anxiety in women was significantly related to 1) a high level of pre-test anxiety and 2) being a mutation carrier. Women without a mutation who had a sister identified as a mutation carrier recently had higher post-test levels of depression than the other non-mutation carriers. It is suggested to consider seriously the need for psychological support in mutation carriers who had been anxious at pre-test already. For most non-mutation carriers, psychological follow-up might be of lesser importance, but those having a sister receiving an unfavorable test result should be informed about the possibility that they might not feel relief.

2
UI - 21371428
AU - Hull SC; Prasad K
TI - Reading between the lines: direct-to-consumer advertising of genetic testing.
SO - Hastings Cent Rep 2001 May-Jun;31(3):33-5

3
UI - 21423701
AU - Wong AS; Kim SO; Leung PC; Auersperg N; Pelech SL
TI - Profiling of protein kinases in the neoplastic transformation of human ovarian surface epithelium.
SO - Gynecol Oncol 2001 Aug;82(2):305-11
AD - Department of Obstetrics and Gynaecology, University of British Columbia, Vancouver, British Columbia, V6H 3V5, Canada.
OBJECTIVE: The aim of this study was to study the pattern of protein kinase expression in a culture model of epithelial ovarian carcinogenesis. METHODS: Cultures of normal human ovarian surface epithelium (OSE), OSE from women with BRCA1 mutations, a cell culture model of preneoplastic (SV40 T-antigen-immortalized, nontumorigenic) and neoplastic (SV40-E-cadherin transfected, tumorigenic) OSE, and three ovarian cancer cell lines were used to represent OSE phenotypes of different genetic backgrounds and at different, progressive stages of neoplastic transformation. The protein kinase network signaling was studied by Western blotting, simultaneously using multiple antibodies for specific protein kinases. RESULTS: High levels of cGMP-dependent protein kinase were found in normal and preneoplastic OSE, but were absent in neoplastic OSE. In contrast, expression of MEK6 was detected exclusively in neoplastic OSE. The expressions of casein kinase II (CK2), p38 mitogen-activated protein kinase (MAPK), cyclin-dependent kinase, and the phosphatidylinositol 3-kinase (PI3K) effectors Akt2 and p70 S6 kinase (S6K) were several-fold higher in neoplastic OSE than in normal OSE, whereas the expressions of the MAPKs extracellular signal-regulated kinases ERK1 and -2 were unchanged. Importantly, constitutive phosphorylation of Akt2 and p70 S6K, as found in neoplastic OSE, was also observed in overtly normal OSE from women with predisposing BRCA1 gene mutations. CONCLUSIONS: These data demonstrate that different repertoires of downstream signaling proteins, particularly those of the MEK6-p38 MAPK-CK2 pathway and the PI3K pathway, are correlated with phenotypic manifestations of a cell culture model of OSE at progressive stages in the development of ovarian cancer. Changes in PI3K effectors are already found in overtly normal OSE from women with BRCA1 mutations. Copyright 2001 Academic Press.

4
UI - 97294417
AU - Gayther SA; Harrington P; Russell P; Kharkevich G; Garkavtseva RF; Ponder BA
TI - Frequently occurring germ-line mutations of the BRCA1 gene in ovarian cancer families from Russia.
SO - Am J Hum Genet 1997 May;60(5):1239-42

5
UI - 21303185
AU - Ricevuto E; Sobol H; Stoppa-Lyonnet D; Gulino A; Marchetti P; Ficorella C; Martinotti S; Meo T; Tosi M
TI - Diagnostic strategy for analytical scanning of BRCA1 gene by fluorescence-assisted mismatch analysis using large, bifluorescently labeled amplicons.
SO - Clin Cancer Res 2001 Jun;7(6):1638-46
AD - Unite Immunogenetique et Unite/Institut National de la Sante et de la Recherche Medicale (INSERM) 276, Institut Pasteur, Paris, France. ricevuto@fismedw2.univaq.it
The aim of this study was to develop a protocol for reliable, sensitive, and cost-effective mutation scanning of the BRCA1 gene, based on a modification of fluorescence-assisted mismatch analysis. The main features of this method are: (a) robust PCR amplification and strandspecific labeling of 25 large amplicons using uniform conditions and universal fluorescent primers; and (b) sensitive characterization of the position of sequence changes. The diagnostic accuracy of this method was tested by scanning the large exon 11 in 12 DNA samples with reported mutations. In a blind test, specific patterns of fluorescence profiles were obtained, and all were attributed correctly, without sequencing, to each mutation or polymorphism. Seven breast/ovarian cancer families with high probability of BRCA1-related predisposition were screened. Three truncating mutations (of which one was novel and three were missense changes, including two novel ones) were detected. The three missense mutations affect the highly conserved BRCT domain. Scanning by FAMA appears to be free of biases for particular types of sequence changes-except for exon deletions/duplications, which cannot be detected by conventional PCR-based methods-and allows substantial savings in the number of sequencing reactions and in the time invested in their interpretation. Therefore, it lends itself to screening structurally complex loci in the diagnostic context and in other fields of genetic analysis.

6
UI - 21396552
AU - Zheng L; Annab LA; Afshari CA; Lee WH; Boyer TG
TI - BRCA1 mediates ligand-independent transcriptional repression of the estrogen receptor.
SO - Proc Natl Acad Sci U S A 2001 Aug 14;98(17):9587-92
AD - Department of Molecular Medicine and Institute of Biotechnology, University of Texas Health Science Center, San Antonio 78245, USA. leew@uthscsa.edu
Mutational inactivation of BRCA1 confers a cumulative lifetime risk of breast and ovarian cancers. However, the underlying basis for the tissue-restricted tumor-suppressive properties of BRCA1 remains poorly defined. Here we show that BRCA1 mediates ligand-independent transcriptional repression of the estrogen receptor alpha (ERalpha), a principal determinant of the growth, differentiation, and normal functional status of breasts and ovaries. In Brca1-null mouse embryo fibroblasts and BRCA1-deficient human ovarian cancer cells, ERalpha exhibited ligand-independent transcriptional activity that was not observed in Brca1-proficient cells. Ectopic expression in Brca1-deficient cells of wild-type BRCA1, but not clinically validated BRCA1 missense mutants, restored ligand-independent repression of ERalpha in a manner dependent upon apparent histone deacetylase activity. In estrogen-dependent human breast cancer cells, chromatin immunoprecipitation analysis revealed the association of BRCA1 with ERalpha at endogenous estrogen-response elements before, but not after estrogen stimulation. Collectively, these results reveal BRCA1 to be a ligand-reversible barrier to transcriptional activation by unliganded promoter-bound ERalpha and suggest a possible mechanism by which functional inactivation of BRCA1 could promote tumorigenesis through inappropriate hormonal regulation of mammary and ovarian epithelial cell proliferation.

7
UI - 20320332
AU - Morrow M
TI - Insurance policies for prophylactic surgery: to cover or not to cover?
SO - Ann Surg Oncol 2000 Jun;7(5):321-2

8
UI - 21250987
AU - Xu X; Li C; Garrett-Beal L; Larson D; Wynshaw-Boris A; Deng CX
TI - Direct removal in the mouse of a floxed neo gene from a three-loxP conditional knockout allele by two novel approaches.
SO - Genesis 2001 May;30(1):1-6
AD - Genetics of Development and Disease Branch, National Institute of Diabetes, Digestive and Kidney Diseases, Bethesda, Maryland, USA.
The presence in an intron of the ploxP-neo-loxP cassette often results in severe interference with gene expression. Consequently, many investigators selectively remove the ploxP-neo-loxP cassette by transient expression of Cre in ES cells. Although effective, the added manipulation of the ES cells may reduce the likelihood that a clone will be able to transmit via the germline. Therefore, we developed two novel approaches that remove the ploxP-neo-loxP by Cre-mediated recombination in mouse. First, the ploxP-neo-loxP-containing mice were crossed with EIIa-Cre transgenic mice. Second, a Cre-expression plasmid was injected into pronuclei of fertilized eggs bearing the ploxP-neo-loxP allele. Both approaches produced mosaic mice with partial and complete excision. These mosaic mice were then mated, and the neo-less conditional knockout allele was found in the offspring after screening only a few litters. These procedures provide options for removing neo directly in the mouse in addition to the commonly used approach that deletes neo in ES cells. Copyright 2001 Wiley-Liss, Inc.

9
UI - 21427512
AU - DiNardo DN; Butcher DT; Robinson DP; Archer TK; Rodenhiser DI
TI - Functional analysis of CpG methylation in the BRCA1 promoter region.
SO - Oncogene 2001 Aug 30;20(38):5331-40
AD - Child Health Research Institute, University of Western Ontario, London, Ontario, Canada.
Understanding the role for DNA methylation in tumorigenesis has evolved from defining the location and extent of methylation in a variety of cancer-related genes to clarifying the functional and site-specific effects of aberrant methylation on gene expression. Our objectives were to characterize the functional effects of DNA methylation in the BRCA1 promoter and to clarify the functional status of the BRCA1 CRE (cAMP response element) motif. Luciferase reporter assays confirm that an intact CRE is important for BRCA1 expression in transient transfections. Luciferase activities were decreased in constructs where the CRE recognition sequence was altered and when constructs were methylated in vitro. Gel mobility shift and competition assays identified a DNA-protein complex recognizing the CRE motif that we were able to supershift using CREB-specific antibody. Furthermore this CRE is methylation sensitive, and we localized this methylation effect to a CpG dinucleotide within the BRCA1 CRE motif. The consequences of aberrant DNA methylation at specific transcription factor motifs, along with the multiple mutational events that can occur in a variety of essential genes such as BRCA1, paint a complex picture where both genetic and epigenetic changes contribute to tumour formation.

10
UI - 21419036
AU - Gui GP; Hogben RK; Walsh G; A'Hern R; Eeles R
TI - The incidence of breast cancer from screening women according to predicted family history risk: Does annual clinical examination add to mammography?
SO - Eur J Cancer 2001 Sep;37(13):1668-73
AD - Department of Academic Surgery, Royal Marsden NHS Trust and Institute of Cancer Research, London, UK. gerald.gui@rhm.nthames.nhs.uk
In breast cancer, mutations of predisposition genes such as BRCA-1/2 and other genes as yet uncharacterised are manifest in up to 10% of cases. Although the prior probability of the presence of a breast cancer predisposing gene can be calculated for individual women, there is no published evidence to justify predicted risk as a selection criteria for screening. This study aims to define which patient groups with a significant family history should be screened, and whether clinical examination is necessary in addition to mammography. The Claus model was used to predict breast cancer risk in women with a family history. Women were divided into two groups according to their predicted risk: group I consisted of women at standard risk (lifetime risk less than 1:6) and group II with moderate/high risk (lifetime risk greater than or equal to 1:6). Women were cancer-free at the point of entry, and screening consisted of annual clinical examination and mammography from the age of 35 years. This study consisted of 1500 women in group I and 1078 in group II. The period of observation was 5902.0 and 4327.8 women years, respectively. A total of 31 cancers were detected, 12 in group I and 19 in group II. The median age at diagnosis in group II was 45 years (range 26-66 years) compared with 54.5 years (range 38-63 years) in group I (P=0.03). The relative risk of developing breast cancer in group II was 2.6 (95% confidence interval (CI) 1.2-5.8). When compared with breast cancer incidence in the normal population, the standardised incidence ratio in group II was significantly higher at 2.8 (95% CI: 1.7-4.2). The standardised incidence ratio of women in group I was similar to that of the general population (1.1 (95% CI: 0.6-1.8)). A total of 26/31 (84%) cancers detected were palpable, of which 14 (54%) were not visible on mammography. Approximately one-third of all palpable cancers were detected at routine follow-up. Mammography correctly identified 17/31 cancers (55%), but 29% of these were not palpable. Family history screening programmes are effective and women should be selected for screening according to predicted risk. The younger age of diagnosis in group II justifies screening from an earlier age using both annual clinical examination and mammography.