BRCA1 requirement for the fidelity of plasmid DNA double-strand break repair in cultured breast epithelial cells

Eric G. Thompson, Hanna F Fares, Kathleen Dixon

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

The tumor suppressor breast cancer susceptibility protein 1 (BRCA1) protects our cells from genomic instability in part by facilitating the efficient repair of DNA double-strand breaks (DSBs). BRCA1 promotes the error-free repair of DSBs through homologous recombination and is also implicated in the regulation of nonhomologous end joining (NHEJ) repair fidelity. Here, we investigate the role of BRCA1 in NHEJ repair mutagenesis following a DSB. We examined the frequency of microhomology-mediated end joining (MMEJ) and the fidelity of DSB repair relative to BRCA1 protein levels in both control and tumorigenic breast epithelial cells. In addition to altered BRCA1 protein levels, we tested the effects of cellular exposure to mirin, an inhibitor of meiotic recombination enzyme 11 (Mre11) 3′-5′-exonuclease activity. Knockdown or loss of BRCA1 protein resulted in an increased frequency of overall plasmid DNA mutagenesis and MMEJ following a DSB. Inhibition of Mre11-exonuclease activity with mirin significantly decreased the occurrence of MMEJ, but did not considerably affect the overall mutagenic frequency of plasmid DSB repair. The results suggest that BRCA1 protects DNA from mutagenesis during nonhomologous DSB repair in plasmid-based assays. The increased frequency of DSB mutagenesis and MMEJ repair in the absence of BRCA1 suggests a potential mechanism for carcinogenesis. Environ. Mol. Mutagen., 2012.

Original languageEnglish (US)
Pages (from-to)32-43
Number of pages12
JournalEnvironmental and Molecular Mutagenesis
Volume53
Issue number1
DOIs
StatePublished - Jan 2012

Fingerprint

BRCA1 Protein
Double-Stranded DNA Breaks
Breast
Plasmids
Epithelial Cells
Mutagenesis
Exonucleases
Genetic Recombination
DNA End-Joining Repair
Proteins
Genomic Instability
Homologous Recombination
DNA
Mutagens
Enzymes
Carcinogenesis

Keywords

  • DNA repair
  • Microhomology-mediated end joining
  • Mirin
  • Mre11
  • Mutation

ASJC Scopus subject areas

  • Health, Toxicology and Mutagenesis
  • Epidemiology
  • Genetics(clinical)

Cite this

BRCA1 requirement for the fidelity of plasmid DNA double-strand break repair in cultured breast epithelial cells. / Thompson, Eric G.; Fares, Hanna F; Dixon, Kathleen.

In: Environmental and Molecular Mutagenesis, Vol. 53, No. 1, 01.2012, p. 32-43.

Research output: Contribution to journalArticle

@article{b5ab9caceb544662b85dad1759c41b54,
title = "BRCA1 requirement for the fidelity of plasmid DNA double-strand break repair in cultured breast epithelial cells",
abstract = "The tumor suppressor breast cancer susceptibility protein 1 (BRCA1) protects our cells from genomic instability in part by facilitating the efficient repair of DNA double-strand breaks (DSBs). BRCA1 promotes the error-free repair of DSBs through homologous recombination and is also implicated in the regulation of nonhomologous end joining (NHEJ) repair fidelity. Here, we investigate the role of BRCA1 in NHEJ repair mutagenesis following a DSB. We examined the frequency of microhomology-mediated end joining (MMEJ) and the fidelity of DSB repair relative to BRCA1 protein levels in both control and tumorigenic breast epithelial cells. In addition to altered BRCA1 protein levels, we tested the effects of cellular exposure to mirin, an inhibitor of meiotic recombination enzyme 11 (Mre11) 3′-5′-exonuclease activity. Knockdown or loss of BRCA1 protein resulted in an increased frequency of overall plasmid DNA mutagenesis and MMEJ following a DSB. Inhibition of Mre11-exonuclease activity with mirin significantly decreased the occurrence of MMEJ, but did not considerably affect the overall mutagenic frequency of plasmid DSB repair. The results suggest that BRCA1 protects DNA from mutagenesis during nonhomologous DSB repair in plasmid-based assays. The increased frequency of DSB mutagenesis and MMEJ repair in the absence of BRCA1 suggests a potential mechanism for carcinogenesis. Environ. Mol. Mutagen., 2012.",
keywords = "DNA repair, Microhomology-mediated end joining, Mirin, Mre11, Mutation",
author = "Thompson, {Eric G.} and Fares, {Hanna F} and Kathleen Dixon",
year = "2012",
month = "1",
doi = "10.1002/em.21674",
language = "English (US)",
volume = "53",
pages = "32--43",
journal = "Environmental and Molecular Mutagenesis",
issn = "0893-6692",
publisher = "Wiley-Liss Inc.",
number = "1",

}

TY - JOUR

T1 - BRCA1 requirement for the fidelity of plasmid DNA double-strand break repair in cultured breast epithelial cells

AU - Thompson, Eric G.

AU - Fares, Hanna F

AU - Dixon, Kathleen

PY - 2012/1

Y1 - 2012/1

N2 - The tumor suppressor breast cancer susceptibility protein 1 (BRCA1) protects our cells from genomic instability in part by facilitating the efficient repair of DNA double-strand breaks (DSBs). BRCA1 promotes the error-free repair of DSBs through homologous recombination and is also implicated in the regulation of nonhomologous end joining (NHEJ) repair fidelity. Here, we investigate the role of BRCA1 in NHEJ repair mutagenesis following a DSB. We examined the frequency of microhomology-mediated end joining (MMEJ) and the fidelity of DSB repair relative to BRCA1 protein levels in both control and tumorigenic breast epithelial cells. In addition to altered BRCA1 protein levels, we tested the effects of cellular exposure to mirin, an inhibitor of meiotic recombination enzyme 11 (Mre11) 3′-5′-exonuclease activity. Knockdown or loss of BRCA1 protein resulted in an increased frequency of overall plasmid DNA mutagenesis and MMEJ following a DSB. Inhibition of Mre11-exonuclease activity with mirin significantly decreased the occurrence of MMEJ, but did not considerably affect the overall mutagenic frequency of plasmid DSB repair. The results suggest that BRCA1 protects DNA from mutagenesis during nonhomologous DSB repair in plasmid-based assays. The increased frequency of DSB mutagenesis and MMEJ repair in the absence of BRCA1 suggests a potential mechanism for carcinogenesis. Environ. Mol. Mutagen., 2012.

AB - The tumor suppressor breast cancer susceptibility protein 1 (BRCA1) protects our cells from genomic instability in part by facilitating the efficient repair of DNA double-strand breaks (DSBs). BRCA1 promotes the error-free repair of DSBs through homologous recombination and is also implicated in the regulation of nonhomologous end joining (NHEJ) repair fidelity. Here, we investigate the role of BRCA1 in NHEJ repair mutagenesis following a DSB. We examined the frequency of microhomology-mediated end joining (MMEJ) and the fidelity of DSB repair relative to BRCA1 protein levels in both control and tumorigenic breast epithelial cells. In addition to altered BRCA1 protein levels, we tested the effects of cellular exposure to mirin, an inhibitor of meiotic recombination enzyme 11 (Mre11) 3′-5′-exonuclease activity. Knockdown or loss of BRCA1 protein resulted in an increased frequency of overall plasmid DNA mutagenesis and MMEJ following a DSB. Inhibition of Mre11-exonuclease activity with mirin significantly decreased the occurrence of MMEJ, but did not considerably affect the overall mutagenic frequency of plasmid DSB repair. The results suggest that BRCA1 protects DNA from mutagenesis during nonhomologous DSB repair in plasmid-based assays. The increased frequency of DSB mutagenesis and MMEJ repair in the absence of BRCA1 suggests a potential mechanism for carcinogenesis. Environ. Mol. Mutagen., 2012.

KW - DNA repair

KW - Microhomology-mediated end joining

KW - Mirin

KW - Mre11

KW - Mutation

UR - http://www.scopus.com/inward/record.url?scp=84855430112&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84855430112&partnerID=8YFLogxK

U2 - 10.1002/em.21674

DO - 10.1002/em.21674

M3 - Article

C2 - 22170030

AN - SCOPUS:84855430112

VL - 53

SP - 32

EP - 43

JO - Environmental and Molecular Mutagenesis

JF - Environmental and Molecular Mutagenesis

SN - 0893-6692

IS - 1

ER -