RELEASE OF TELOMERIC DNA FROM CHROMOSOMES IN IMMORTAL HUMAN-CELLS LACKING TELOMERASE ACTIVITY

Some immortal human cell lines lack telomerase activity. These cell li nes were found to contain small dispersed DNA hybridizing to TTAGGG: r epeats. Such DNA was located in their cytoplasm and nuclei, Normal hum an fibroblasts or telomerase-positive cell lines did not contain such DNA. Upon cloning and sequencing, it was shown to consist of TTAGGG re peats. When electrophoresed on neutral and alkaline agarose gels, it b ehaved as double-stranded and linear DNA. These results suggest that t elomeric DNA is released from chromosomes in association with maintena nce of telomeres in telomerase-negative cell lines. (C) 1998 Academic Press.