title: Absence or low number of telomere repeats at junctions of dicentric chromosomes.
abstract: Human ovarian surface epithelial (HOSE) cells transfected with the E6 and E7 oncogenes of the human papilloma virus (PV) do not express measurable telomerase activity. Relative to untransfected control cells, HOSE-PV cells have an extended in vitro lifespan characterized by a very high frequency of telomeric associations (TAs) of chromosomes. In order 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 the junction site, and in the remainder the fluorescence at the junction was less than at corresponding unjoined ends. These observations support a critical role of telomere shortening in the development of TAs and the subsequent genetic instability observed in a majority of tumor cells.
authors.affiliation: Department of Anatomy, Faculty of Medicine, University of Hong Kong, Hong Kong.
authors.forename: T S
authors.initials: TS
authors.lastname: Wan
authors.forename: U M
authors.initials: UM
authors.lastname: Martens
authors.forename: S S
authors.initials: SS
authors.lastname: Poon
authors.forename: S W
authors.initials: SW
authors.lastname: Tsao
authors.forename: L C
authors.initials: LC
authors.lastname: Chan
authors.forename: P M
authors.initials: PM
authors.lastname: Lansdorp
mesh_terms: D002478:Cells, Cultured; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods; D009856:Oncogene Proteins, Viral / Q000235:genetics; D010053:Ovary; D027383:Papillomaviridae / Q000235:genetics; D050725:Papillomavirus E7 Proteins; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics*; D012097:Repressor Proteins; D016615:Telomere / Q000737:chemistry / Q000235:genetics*
chemical_list: C068651:E6 protein, Human papillomavirus type 16; D009856:Oncogene Proteins, Viral; D050725:Papillomavirus E7 Proteins; D012097:Repressor Proteins; C059731:oncogene protein E7, Human papillomavirus type 16