title: BRCA1 knock-down causes telomere dysfunction in mammary epithelial cells.
abstract: A breast cancer predisposing gene, BRCA1, is a major suppressor of chromosomal instability and its dysfunction affects multiple pathways involved in DNA damage response. There is increasing evidence that the mechanisms involved in maintenance of telomeres, specialized structures at chromosome ends, are linked with DNA damage response. We therefore investigated whether BRCA1 dysfunction affects telomere maintenance. To achieve this we knocked-down BRCA1 in two mammary epithelial cell lines using RNA interference. Subsequent analysis by immunofluorescence, RT-PCR and Western blotting revealed that a short interfering RNA oligonucleotide used was able to knock-down BRCA1 efficiently. This knock-down did not have any effect on telomerase enzyme activity and telomere length. However, BRCA1 knock-down correlated with the increase in chromatin bridges in anaphase cells which usually reflect telomere dysfunction. Therefore, this study suggests that BRCA1 knockdown in mammary epithelial cells causes telomere dysfunction.
authors.affiliation: Brunel Institute of Cancer Genetics and Pharmacogenomics, School of Health Sciences and Social Care, Brunel University, Uxbridge, Middlesex, UK.
authors.forename: E
authors.initials: E
authors.lastname: Cabuy
authors.forename: C
authors.initials: C
authors.lastname: Newton
authors.forename: P
authors.initials: P
authors.lastname: Slijepcevic
mesh_terms: D019313:BRCA1 Protein / Q000172:deficiency / Q000235:genetics* / Q000378:metabolism; D001943:Breast Neoplasms / Q000235:genetics*; D018929:Cell Culture Techniques; D002460:Cell Line; D004249:DNA Damage; D017931:DNA Primers; D004847:Epithelial Cells / Q000502:physiology*; D005260:Female; D005784:Gene Amplification; D006801:Humans; D007150:Immunohistochemistry; D042361:Mammary Glands, Human / Q000166:cytology / Q000502:physiology*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016615:Telomere / Q000235:genetics*; D014162:Transfection
chemical_list: D019313:BRCA1 Protein; D017931:DNA Primers; D034741:RNA, Small Interfering