title: Chromosomal radiosensitivity of breast cancer with a CHEK2 mutation.
abstract: Recently, multiple studies have shown that a sequence variant in CHEK2 (CHEK2 1100delC) plays a role in the susceptibility to breast cancer. This mutation should confer about a twofold increased breast cancer risk in women and a 10-fold increased risk in men. Because the CHEK2 gene plays a critical role in DNA damage repair and the CHEK2 1100delC variant confers susceptibility to breast cancer, we investigated if patients carrying the CHEK2 1100delC mutation are characterized by an enhanced chromosomal radiosensitivity. To this end, familial breast cancer patients, sporadic breast cancer patients, and healthy women, considered in our previously studied to determine their chromosomal radiosensitivity with the G2 and G0-MN assay, were all tested in present study for the presence of the CHEK2 1100delC variant. The 1100delC variant was detected in none of the 100 healthy individuals, in 1 of 100 (1%) unselected breast cancer patients and in 3 of 78 (3.8%) breast cancer patients with a family history of breast cancer. The breast cancer patients with the CHEK2 1100delC genotype had a mean radiation-induced yield of chromatid breaks that was not significantly different from that of the healthy control group. Although the mean yield of micronuclei (MN) was significantly higher compared to the healthy control group, this higher mean MN yield was due to a single patient who had a very high number of MN compared to the parallel control. Our data suggest that breast cancer patients with a CHEK2 1100delC mutation are in general not characterized by a distinct enhanced chromosomal radiosensitivity. These conclusions are, however, very preliminary, because of the small numbers of CHEK2 1100delC breast cancer patients studied.
authors.affiliation: Department of Anatomy, Embryology, Histology and Medical Physics, Ghent University, and Center for Medical Genetics, Gent University Hospital, Belgium. ansbaeyens@hotmail.com
authors.forename: Ans
authors.initials: A
authors.lastname: Baeyens
authors.forename: Kathleen
authors.initials: K
authors.lastname: Claes
authors.forename: Petra
authors.initials: P
authors.lastname: Willems
authors.forename: Kim
authors.initials: K
authors.lastname: De Ruyck
authors.forename: Hubert
authors.initials: H
authors.lastname: Thierens
authors.forename: Anne
authors.initials: A
authors.lastname: Vral
mesh_terms: D001483:Base Sequence; D001943:Breast Neoplasms / Q000235:genetics*; D016022:Case-Control Studies; D064447:Checkpoint Kinase 2; D002877:Chromosomes, Human; D004249:DNA Damage; D017931:DNA Primers; D004260:DNA Repair; D005260:Female; D005838:Genotype; D006801:Humans; D015162:Micronucleus Tests; D009154:Mutation; D017346:Protein Serine-Threonine Kinases / Q000235:genetics*; D011836:Radiation Tolerance; D016192:Resting Phase, Cell Cycle
chemical_list: D017931:DNA Primers; D064447:Checkpoint Kinase 2; C578634:CHEK2 protein, human; D017346:Protein Serine-Threonine Kinases