title: Analysis of the FHIT gene and FRA3B region in sporadic breast cancer, preneoplastic lesions, and familial breast cancer probands.
abstract: The FHIT gene, which spans the FRA3B fragile site at chromosome 3p14.2, is a candidate tumor suppressor gene in breast and other cancers. We investigated FHIT and FRA3B for loss of heterozygosity (LOH); homozygous deletions; abnormal transcripts; and acquired/germ-line point mutations in breast cancer cell lines (n = 32), breast epithelial and stromal cell cultures (n = 18), microdissected invasive (n = 16) and ductal in situ carcinomas (n = 6), and their accompanying normal and abnormal epithelial foci (n = 14). LOH at 3p14.2, especially at FHIT intragenic marker D3S1300, was found in 6 of 16 microdissected invasive tumors and 3 of 6 ductal in situ carcinomas. In accompanying preneoplastic foci, LOH occurred in two of eight intraductal hyperplasias but not in histologically normal ductal epithelium (n = 6). Three of 32 (9%) breast cancer cell lines demonstrated homozygous deletions of FHIT exon 4 (two cases) and exon 5 (one case), which correlated with exon 4-deleted transcripts and loss of the cDNA transcript containing the coding exons 5-9, respectively. Normal mammary cultures and 31 of 32 tumor cell lines (97%) expressed wild-type coding transcripts as well as a minor exon 8-deleted message. Single-strand conformation polymorphism analysis of the coding exons in the 32 tumor and 18 normal breast cell lines and their sequencing revealed four silent polymorphisms and a germ-line histidine triad point mutation (651 G-->T) in a tumor arising in a 70-year-old woman. This mutation was also present in one of her two thus far unaffected daughters. Analysis of additional DNAs from 280 probands of high-risk breast cancer families for other FHIT exon 8 mutations detected an intronic point mutation 13 bases upstream of exon 8. Thus, we have demonstrated relatively early abnormalities of the FHIT/FRA3B region in breast cancer and discovered two rare FHIT germ-line mutations. The expression of a transcript containing the coding exons in nearly all cell lines, including those with germ-line mutations, suggests the possibility that another gene in the FRA3B region may be involved in the pathogenesis of breast cancer.
authors.affiliation: Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, Dallas 75235-8593, USA.
authors.forename: M
authors.initials: M
authors.lastname: Ahmadian
authors.forename: I I
authors.initials: II
authors.lastname: Wistuba
authors.forename: K M
authors.initials: KM
authors.lastname: Fong
authors.forename: C
authors.initials: C
authors.lastname: Behrens
authors.forename: D R
authors.initials: DR
authors.lastname: Kodagoda
authors.forename: M H
authors.initials: MH
authors.lastname: Saboorian
authors.forename: J
authors.initials: J
authors.lastname: Shay
authors.forename: G E
authors.initials: GE
authors.lastname: Tomlinson
authors.forename: J
authors.initials: J
authors.lastname: Blum
authors.forename: J D
authors.initials: JD
authors.lastname: Minna
authors.forename: A F
authors.initials: AF
authors.lastname: Gazdar
mesh_terms: D017766:Acid Anhydride Hydrolases; D001943:Breast Neoplasms / Q000235:genetics*; D002278:Carcinoma in Situ / Q000235:genetics; D018270:Carcinoma, Ductal, Breast / Q000235:genetics; D043283:Chromosome Fragile Sites; D002873:Chromosome Fragility; D002893:Chromosomes, Human, Pair 3 / Q000235:genetics*; D005190:Family; D005260:Female; D017353:Gene Deletion; D006801:Humans; D009363:Neoplasm Proteins / Q000235:genetics; D017354:Point Mutation / Q000235:genetics*; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D011230:Precancerous Conditions / Q000235:genetics*; D011506:Proteins / Q000235:genetics; D000099170:Bis(5'-adenosyl)triphosphatase
chemical_list: D017766:Acid Anhydride Hydrolases; D009363:Neoplasm Proteins; D011506:Proteins; D000099170:Bis(5'-adenosyl)triphosphatase