ABSENCE OR LOW NUMBER OF TELOMERE REPEATS AT JUNCTIONS OF DICENTRIC CHROMOSOMES

Human ovarian surface epithelial (HOSE) cells transfected with the E6 and E7 oncogenes of the human papilloma virus (PV) do not express meas urable telomerase activity. Relative to untransfected control cells, H OSE-PV cells have an extended in vitro lifespan characterized by a ver y high frequency of telomeric associations (TAs) of chromosomes. In or der to study the role of telomere shortening in the formation of TAs, we studied the telomere length in 120 dicentric chromosomes in HOSE-PV cells by using quantitative fluorescence in situ hybridization. Forty percent of the dicentric chromosomes had no fluorescence signal at th e junction site, and in the remainder the fluorescence at the junction was less than at corresponding unjoined ends. These observations supp ort a critical role of telomere shortening in the development of TAs a nd the subsequent genetic instability observed in a majority of tumor cells. Genes Chromosomes Cancer 24:83-86, 1999. (C) 1999 Wiley-Liss, I nc.