title: BRCA1 is differentially expressed in human tumor cells.
abstract: Mutations of the human breast cancer susceptibility gene 1 (BRCA1) confers a risk for breast, ovarian and prostate cancers and BRCA1 exerts multiple biological functions. Using Western blot and semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) assays, we have determined the expression of endogenous BRCA1 protein and mRNA in forty-three human tumor cell lines established from eleven types of human tumor tissues. BRCA1 was differentially expressed in tumor cell lines. No significant association was found between BRCA1 expression and the p53 gene status of cell lines. The disruption of wild-type p53 by either the human papillomavirus E6 oncogene or the mutant p53 gene (143Ala-->Val) did not cause any significant alteration in basal level of BRCA1 expression, while the knockout of p21 (-/-) by homologous recombination assay and Blocking Gadd45 expression by constitutive antisense expression slightly increased BRCA1 protein expression. Therefore, although the functional significance of the differential expression in human tumor cells is currently unknown, the present data provide a valuable background for further study of BRCA1 in tumor cell lines.
authors.affiliation: Laboratory of Molecular Oncology, Department of Radiation Oncology, Long Island Jewish Medical Center, Long Island Campus for the Albert Einstein College of Medicine, New York 11042, USA.
authors.forename: Q H
authors.initials: QH
authors.lastname: Meng
authors.forename: R Q
authors.initials: RQ
authors.lastname: Yuan
authors.forename: I D
authors.initials: ID
authors.lastname: Goldberg
authors.forename: E M
authors.initials: EM
authors.lastname: Rosen
authors.forename: S J
authors.initials: SJ
authors.lastname: Fan
mesh_terms: D019313:BRCA1 Protein / Q000096:biosynthesis / Q000235:genetics*; D001943:Breast Neoplasms / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic; D016158:Genes, p53 / Q000235:genetics*; D006801:Humans; D009154:Mutation; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured
chemical_list: D019313:BRCA1 Protein; D012333:RNA, Messenger