BRCA1 Mutations in Familial Ovarian Cancer

Lallas, Thomas A.; Buekers, Thomas E.; Buller, Richard E.

doi:10.1006/mgme.1999.2871

Cited by 16 publications

(14 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The involvement of BRCA1 in the stability of common fragile sites after replication perturbations is of interest in light of the importance of BRCA1 in tumorigenesis. Loss of heterozygosity of BRCA1 has been associated with increased susceptibility to breast and ovarian cancer, and null mutations in BRCA1 have been found to persist in cancer cells (18,42). Cells lacking BRCA1 will likely be prone to genomic alterations that lead to deletions of associated genes, including those at fragile sites, as has been seen in multiple cancers (1,17,21,23,28,38).…”

Section: Discussionmentioning

confidence: 99%

BRCA1 Is Required for Common-Fragile-Site Stability via Its G₂/M Checkpoint Function

Arlt

Durkin

et al. 2004

Molecular and Cellular Biology

114

View full text Add to dashboard Cite

Common fragile sites are loci that form chromosome gaps or breaks when DNA synthesis is partially inhibited. Fragile sites are prone to deletions, translocations, and other rearrangements that can cause the inactivation of associated tumor suppressor genes in cancer cells. It was previously shown that ATR is critical to fragile-site stability and that ATR-deficient cells have greatly elevated fragile-site expression (A. M. Casper, P. Nghiem, M. F. Arlt, and T. W. Glover, Cell 111:779-789, 2002). Here we demonstrate that mouse and human cells deficient for BRCA1, due to mutation or knockdown by RNA interference, also have elevated fragile-site expression. We further show that BRCA1 functions in the induction of the G 2 /M checkpoint after aphidicolininduced replication stalling and that this checkpoint function is involved in fragile-site stability. These data indicate that BRCA1 is important in fragile-site stability and that fragile sites are recognized by the G 2 /M checkpoint pathway, in which BRCA1 plays a key role. Furthermore, they suggest that mutations in BRCA1 or interacting proteins could lead to rearrangements at fragile sites in cancer cells.Common fragile sites are loci that exhibit site-specific gaps and breaks on metaphase chromosomes when cells are grown under conditions that partially inhibit DNA synthesis, such as folate deficiency or treatment with aphidicolin (11). These fragile sites extend over hundreds of kilobases, with gaps and breaks occurring throughout the regions. Following aphidicolin treatment, 80% of all gaps and breaks are seen at just 20 fragile sites, with FRA3B (3p14.2) and FRA16D (16q23) being the most frequently broken, or expressed, fragile sites (11). Whereas rare fragile sites, such as FRAXA within the FMR1 gene, arise from mutation at di-or trinucleotide repeats, common fragile sites are found in all individuals and represent a normal component of chromosome structure.Fragile sites are so-called hot spots for sister chromatid exchanges, translocations, deletions, and plasmid integration in cultured cells following replication stress (12,14,32,40). Numerous studies have also shown that common fragile sites are prone to deletions and rearrangements in many cancers (1,17,21,28,33), and they may play a role in some gene amplification and viral integration events (6,16,26,41). Some fragile sites lie within putative tumor suppressor genes, such as FHIT at FRA3B and WWOX at FRA16D (30, 33), leading to the model that fragile-site instability is a contributing factor in tumorigenesis.Determining the mechanisms of fragile-site instability is important in understanding normal chromosome structure and DNA replication as well as the instability found at fragile sites in tumor cells. Sequence analysis of common fragile sites has not revealed why they are unstable. However, all sites studied to date are relatively AT rich and contain more areas of high flexibility than non-fragile-site regions (22,(24)(25)(26)(27). Studies examining replication timing at common fragile sites have shown...

show abstract

Section: Discussionmentioning

confidence: 99%

BRCA1 Is Required for Common-Fragile-Site Stability via Its G₂/M Checkpoint Function

Arlt

Durkin

et al. 2004

Molecular and Cellular Biology

114

View full text Add to dashboard Cite

show abstract

“…Initially our group reported a set of BRCA1 mutations detected in a cohort of 81 patients with ovarian, peritoneal, or fallopian tube carcinoma [Lallas et al, 1999]. Twenty-four additional patients have been screened with the same methods.…”

Section: Methodsmentioning

confidence: 99%

“…The methods used for the SSCP analysis were as described [Lallas and Buller, 1998;Lallas et al, 1999]. Genomic DNA was PCR amplified for 22 of the 24 exons (exons 1 and 4 were not analyzed) of the BRCA1 gene using primer sets that yielded 230450 base pair amplimers [Friedman et al, 1994].…”

Section: Sscp Analysismentioning

confidence: 99%

“…Genomic DNA was PCR amplified for 22 of the 24 exons (exons 1 and 4 were not analyzed) of the BRCA1 gene using primer sets that yielded 230450 base pair amplimers [Friedman et al, 1994]. The amplimers were subjected to electrophoresis on exon specific gels and conditions as before [Lallas and Buller, 1998;Lallas et al, 1999;Friedman et al, 1994;Castilla et al, 1994;Holt et al, 1994]. Internally 32 P labeled fragments from exons 3,11,13,[15][16]18, and 2022 were also screened by restriction digests prior to electrophoresis as originally described by Inoue et al [Inoue et al, 1995].…”

Section: Sscp Analysismentioning

confidence: 99%

“…Unfortunately, null mutations in BRCA1 are the rule, not the exception. While the potential utility of SSCP in screening ovarian cancers for BRCA1 is well known, there are a number of nuances to screening with this method [Lallas and Buller, 1998;Lallas et al, 1999]. The need for 41 individual PCR reactions remains problematic.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Ovarian cancer BRCA1 mutation detection: Protein truncation test (PTT) outperforms single strand conformation polymorphism analysis (SSCP)

et al. 2001

View full text Add to dashboard Cite

Recent studies have shown that the BRCA1 tumor suppressor gene plays a role in the development of both hereditary and sporadic ovarian cancer. Since several different mechanisms may give rise to tumor gene defects, a better understanding of these mechanisms may identify BRCA1 as an attractive therapeutic target in ovarian cancer. Sequencing this large gene is not practical on a population-wide basis. The optimal screening strategy is yet to be determined. The purpose of our study is to compare two common screening techniques: the protein truncation test (PTT) and single strand conformational polymorphism analysis (SSCP). Ninety-four patients with epithelial ovarian cancer and available snap-frozen tissue were screened for BRCA1 mutations by both PTT (five individual PCR reactions with complete translation of the product in the TNT System (Promega, Madison, WI)) and SSCP (41 individual PCR reactions covering the entire coding sequence). All abnormal results were confirmed by sequencing. A paired peripheral blood DNA sample was utilized to determine if the sequence abnormality was a germline mutation. Twentythree mutations in BRCA1 were found in 22 patients (14 germline, eight somatic, one unknown) including four novel mutations: E489X, 3558delT, 3871delGTCT, del exon 710. Although the predictive value of a negative test was close for the two methods (PTT 99.1%, SSCP 99.8%), the comparison of positive predictive value overwhelmingly favored PTT (100.0%, vs. 26.4%, respectively). The specificity for PTT was 100.0% while the sensitivity was 82.6%. While for SSCP, the specificity was 99.0% and the sensitivity was only 60.9%. The concordance rate for the two screening tests was 88.9%. Only SSCP can detect missense mutations. PTT is a superior screening test for truncating BRCA1 mutations that are expected to be of clinical significance. Hum Mutat 18:337 344, 2001.

show abstract

Xp22.2-3 Loss of Heterozygosity Is Associated with Germline BRCA1 Mutation in Ovarian Cancer

Buekers

Lallas

Buller

2000

Gynecologic Oncology

View full text Add to dashboard Cite

BRCA1 Mutations in Familial Ovarian Cancer

Cited by 16 publications

References 21 publications

BRCA1 Is Required for Common-Fragile-Site Stability via Its G₂/M Checkpoint Function

BRCA1 Is Required for Common-Fragile-Site Stability via Its G₂/M Checkpoint Function

Ovarian cancer BRCA1 mutation detection: Protein truncation test (PTT) outperforms single strand conformation polymorphism analysis (SSCP)

Xp22.2-3 Loss of Heterozygosity Is Associated with Germline BRCA1 Mutation in Ovarian Cancer

Contact Info

Product

Resources

About

BRCA1 Mutations in Familial Ovarian Cancer

Cited by 16 publications

References 21 publications

BRCA1 Is Required for Common-Fragile-Site Stability via Its G2/M Checkpoint Function

BRCA1 Is Required for Common-Fragile-Site Stability via Its G2/M Checkpoint Function

Ovarian cancer BRCA1 mutation detection: Protein truncation test (PTT) outperforms single strand conformation polymorphism analysis (SSCP)

Xp22.2-3 Loss of Heterozygosity Is Associated with Germline BRCA1 Mutation in Ovarian Cancer

Contact Info

Product

Resources

About

BRCA1 Is Required for Common-Fragile-Site Stability via Its G₂/M Checkpoint Function

BRCA1 Is Required for Common-Fragile-Site Stability via Its G₂/M Checkpoint Function