Ionizing radiation or mitomycin-induced micronuclei in lymphocytes of BRCA1 or BRCA2 mutation carriers
Por:
Gutierrez-Enriquez, S, Cajal, TRY, Alonso, C, Corral, A, Carrasco, P, Cornet, M, Sanz, J, Ribas, M, Baiget, M, Diez, O
Publicada:
1 jun 2011
Resumen:
BRCA1 and BRCA2 genes are essential in preserving the integrity of genome, and it is not unambiguously clear whether the heterozygosity status may affect BRCA1 or BRCA2 functions. This may have implications for the clinical management of BRCA1 and BRCA2 mutation carriers both in breast cancer (BC) screening modality and in cancer treatment based on DNA-damaging or DNA-repair-inhibiting drugs. We investigated whether lymphocytes carrying BRCA1 or BRCA2 mutations displayed an increased sensitivity to radiation or mitomycin C (MMC) in vitro treatments. Peripheral blood from 21 BRCA1 mutation carriers (12 with BC and 9 healthy), 24 BRCA2 carriers (13 with BC and 11 healthy), 15 familial BC patients without detected mutation in BRCA1 or BRCA2 and 16 controls without familial history of cancer (5 with BC and 11 healthy) were irradiated or treated with MMC. Chromosomal damage was measured using the cytokinesis-block micronucleus assay. We evaluated micronuclei (MN) and nucleoplasmic bridges (NPBs). The BRCA2 mutation carriers and familial BC patients without detected mutation in BRCA1 or BRCA2 showed less basal NPB than BRCA1 carriers and controls. The BRCA1 (+/-) or BRCA2 (+/-) lymphocytes did not have increased frequencies of MN or NPB after irradiation. In contrast, BRCA2 (+/-) lymphocytes presented higher levels of MN after MMC exposure than BRCA1 carriers and controls. The monoallelic BRCA1 or BRCA2 pathogenic mutations seem not to be associated with an enhanced radiosensitivity. The mutation of one BRCA2 allele conferred an increased sensitivity to MMC, presumably because of the role of this gene in the repair of MMC-induced DNA damage. This finding indicates that the MMC-induced MN analysis could be useful in identifying functional deficiencies of BRCA2 or genes related to BRCA2. Since MMC can be used as an anti-cancer drug, these data may be relevant for the management and follow-up of BRCA2 mutation carriers.
Filiaciones:
Gutierrez-Enriquez, S:
Univ Hosp Vall Hebron, Clin Labs, Oncogenet Lab, Barcelona 08035, Spain
VHIO, Barcelona, Spain
Vall Hebron Univ Hosp, Med Oncol Program, Res Inst, Barcelona, Spain
Cajal, TRY:
Santa Creu & St Pau Hosp, Dept Med Oncol, Barcelona, Spain
Alonso, C:
Santa Creu & St Pau Hosp, Dept Med Oncol, Barcelona, Spain
Corral, A:
Autonomous Univ Barcelona, Dept Genet & Microbiol, Grp Mutagenesis, Cerdanyola Del Valles, Spain
Carrasco, P:
Santa Creu & St Pau Hosp, Radiophys & Radioprotect Dept, Barcelona, Spain
Cornet, M:
Santa Creu & St Pau Hosp, Dept Genet, Barcelona, Spain
Sanz, J:
Santa Creu & St Pau Hosp, Dept Med Oncol, Barcelona, Spain
Ribas, M:
Santa Creu & St Pau Hosp, Radiophys & Radioprotect Dept, Barcelona, Spain
Baiget, M:
Santa Creu & St Pau Hosp, Dept Genet, Barcelona, Spain
Diez, O:
Univ Hosp Vall Hebron, Clin Labs, Oncogenet Lab, Barcelona 08035, Spain
VHIO, Barcelona, Spain
Open Access
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