title: Loss of heterozygosity at 11q23.1 in breast carcinomas: indication for involvement of a gene distal and close to ATM.
abstract: Previous reports have suggested that heterozygotes for ataxia-telangiectasia (A-T) have an increased risk of cancer, in particular breast cancer. The ATM gene, responsible for A-T, was recently cloned. Loss of heterozygosity (LOH) in the chromosome band 11q23, where the ATM gene is located, has been reported in several types of tumours including breast carcinomas. Whether the ATM gene is the target, and the sole target, for the LOH seen in this region is not yet known. In this study, 169 primary breast carcinomas and 10 metastases were examined for allelic imbalance (AI) using 10 microsatellite markers mapping to 11q23.1. Nine of the markers reside within a 10 Mb region surrounding the ATM gene, whereas the tenth locus, APOC-3, is located more than 12 Mb telomeric from this region. The highest frequencies of alteration were found for APOC-3 (45%), and for two markers located approximately 200 and 900 kb telomeric from ATM, D11S1294 (44%) and D11S1818 (44%). The marker located within the ATM gene, D11S2179, was altered in 37% of the informative tumours. The present deletion map indicates that three distinct regions at 11q23.1 may be involved in breast cancer development; one between the markers D11S1294 and D11S1818, a second close to APOC-3, and a third that is possibly the ATM-gene itself.
authors.affiliation: Department of Genetics, Norwegian Radium Hospital, Montebello, Oslo, Norway.
authors.forename: K
authors.initials: K
authors.lastname: Laake
authors.forename: A
authors.initials: A
authors.lastname: Odegård
authors.forename: T I
authors.initials: TI
authors.lastname: Andersen
authors.forename: I K
authors.initials: IK
authors.lastname: Bukholm
authors.forename: R
authors.initials: R
authors.lastname: Kåresen
authors.forename: J M
authors.initials: JM
authors.lastname: Nesland
authors.forename: L
authors.initials: L
authors.lastname: Ottestad
authors.forename: Y
authors.initials: Y
authors.lastname: Shiloh
authors.forename: A L
authors.initials: AL
authors.lastname: Børresen-Dale
mesh_terms: D000328:Adult; D000368:Aged; D000483:Alleles; D001260:Ataxia Telangiectasia / Q000150:complications / Q000235:genetics; D064007:Ataxia Telangiectasia Mutated Proteins; D001943:Breast Neoplasms / Q000150:complications / Q000235:genetics* / Q000473:pathology; D018797:Cell Cycle Proteins; D002869:Chromosome Aberrations; D002874:Chromosome Mapping; D002880:Chromosomes, Human, Pair 11 / Q000235:genetics; D004273:DNA, Neoplasm / Q000032:analysis; D004268:DNA-Binding Proteins; D005260:Female; D017353:Gene Deletion; D006579:Heterozygote; D006801:Humans; D018895:Microsatellite Repeats; D008875:Middle Aged; D009362:Neoplasm Metastasis; D016133:Polymerase Chain Reaction; D017346:Protein Serine-Threonine Kinases; D011506:Proteins / Q000235:genetics*; D025521:Tumor Suppressor Proteins
chemical_list: D018797:Cell Cycle Proteins; D004273:DNA, Neoplasm; D004268:DNA-Binding Proteins; D011506:Proteins; D025521:Tumor Suppressor Proteins; C576324:ATM protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; D017346:Protein Serine-Threonine Kinases