Líffræðifélag Íslands
Líffræðiráðstefnan 2015
Erindi/veggspjald / Talk/poster V73
Birna Þorvaldsdottir (1), Beth A. Cimini (2), Morgan E. Diolaiti (3), Margrét Aradóttir (1), Katrín Ólafsdottir (4), Jón G. Jónasson (4), Elizabeth H. Blackburn (2), Jórunn E. Eyfjörð (1)
1. Cancer Research Laboratory, Biomedical Center, University of Iceland, 2. Department of Biochemistry and Biophysics, University of California-San Francisco, 3. Department of Pathology, University of California-San Francisco and 4. Department of Pathology, Landspitali University Hospital
Kynnir / Presenter: Birna Þorvaldsdóttir
Tengiliður / Corresponding author: Birna Þorvaldsdóttir (bth60@hi.is)
Germline mutations in the BRCA2 gene are associated with highly increased risk of breast cancer. The BRCA2 protein has a role in homologous recombination repair and has been associated with telomere protection and maintenance. Dysfunctional telomere maintenance can lead to excessive telomere shortening which causes chromosome instability, a hallmark of many cancers. The aim of the study was to investigate if telomere length and dysfunction in normal breast tissue is correlated with breast cancer progression and survival in a well-defined group of BRCA2 mutation carriers and sporadic breast cancer cases. Telomere length measurements were carried out on normal breast tissue samples embedded in paraffin by using the Quantitative Fluorescence in Situ Hybridization method (Q-FISH). The same samples were stained for 53BP1, a double strand break marker. Telomere dysfunction induced foci (TIFs) were detected where co-localization of telomere and 53BP1 signals occurred. The results show a clear difference in telomere length of different cell types in normal breast tissue with inner epithelial cells having shorter telomeres than both myoepithelial cells and fibroblasts, supporting previously reported data. 53BP1 foci, including TIFs, are present in much higher numbers in inner epithelial cells than other cells of the breast. In mutation carriers, there are indications that less variable telomere length in normal adjacent tissue is associated with reduced breast cancer specific survival.