ABSTRACT
OBJECTIVES: This study assessed the BRCA1 gene expression in breast cancer in Kuwait, and compared it with other known prognostic factors for the disease. MATERIALS AND METHODS: Forty-eight random samples of archival paraffin-embedded breast cancer tissues were studied for BRCA1 gene expression. Immunohistochemical method utilizing antibodies against different epitopes on the BRCA1 protein was used to study BRCA1 protein expression. In addition, for 29 patients, reverse transcription-polymerase chain reaction was used to detect BRCA1 mRNA expression. BRCA1 expression was correlated with age, histological type and grade of breast cancer, estrogen and progesterone receptor status, and C-erbB-2 expression. RESULTS: No demonstrable BRCA1 mRNA and protein expression was found in 79 and 83% of the breast cancer tissues, respectively. A positive relationship was demonstrated between lack of BRCA1 (mRNA and protein) expression and high histological grade, negative estrogen and progesterone receptor status, and overexpression of C-erbB-2 in the breast cancer tissues. CONCLUSIONS: The study demonstrated lack of BRCA1 gene expression (mRNA and protein) in the majority of breast cancers in Kuwait and confirmed the inverse relationship between BRCA1 expression and parameters that determine poor prognosis in breast cancer.
Subject(s)
Breast Neoplasms/genetics , Gene Expression Regulation, Neoplastic , Genes, BRCA1 , Adult , Aged , Base Sequence , Breast Neoplasms/metabolism , Breast Neoplasms/physiopathology , DNA Primers , Female , Genes, erbB-2 , Humans , Kuwait , Middle Aged , Prognosis , RNA, Messenger/genetics , Receptors, Estrogen/genetics , Receptors, Estrogen/metabolism , Receptors, Progesterone/genetics , Receptors, Progesterone/metabolism , Reverse Transcriptase Polymerase Chain ReactionABSTRACT
AIMS: To describe a cytogenetic technique suitable for the rapid assessment of global gene expression that is based on comparative genomic hybridisation (CGH), and to use it to understand the relation between genetic amplifications and gene expression. METHODS: Whereas traditional CGH uses DNA as test and reference in hybridisations, expressive genomic hybridisation (EGH) uses globally amplified mRNA as test and normal DNA as reference. EGH is a rapid and powerful tool for localising and studying global gene expression profiles and correlating them with loci of genetic amplifications using traditional CGH. RESULTS: EGH was used to correlate genetic amplifications detected by CGH with the expression profile of two independent cell lines-Colo320 and T47D. Although many amplifications resulted in overexpression, other amplifications were partially or completely silenced at the cytogenetic level. CONCLUSION: This technique will assist in the analysis of overexpressed genes within amplicons and could resolve a controversial issue in cancer cytogenetics; namely, the relation between genetic amplifications and overexpression.
