Disappearance of the telomere dysfunction-induced stress response in fully senescent cells.

Published

Journal Article

Replicative senescence is a natural barrier to cellular proliferation that is triggered by telomere erosion and dysfunction. Here, we demonstrate that ATM activation and H2AX-gamma nuclear focus formation are sensitive markers of telomere dysfunction in primary human fibroblasts. Whereas the activated form of ATM and H2AX-gamma foci were rarely observed in early-passage cells, they were readily detected in late-passage cells. The ectopic expression of telomerase in late-passage cells abrogated ATM activation and H2AX-gamma focus formation, suggesting that these stress responses were the consequence of telomere dysfunction. ATM activation was induced in quiescent fibroblasts by inhibition of TRF2 binding to telomeres, indicating that telomere uncapping is sufficient to initiate the telomere signaling response; breakage of chromosomes with telomeric associations is not required for this activation. Although ATM activation and H2AX-gamma foci were readily observed in late-passage cells, they disappeared once cells became fully senescent, indicating that constitutive signaling from dysfunctional telomeres is not required for the maintenance of senescence.

Full Text

Duke Authors

Cited Authors

  • Bakkenist, CJ; Drissi, R; Wu, J; Kastan, MB; Dome, JS

Published Date

  • June 2004

Published In

Volume / Issue

  • 64 / 11

Start / End Page

  • 3748 - 3752

PubMed ID

  • 15172978

Pubmed Central ID

  • 15172978

Electronic International Standard Serial Number (EISSN)

  • 1538-7445

International Standard Serial Number (ISSN)

  • 0008-5472

Digital Object Identifier (DOI)

  • 10.1158/0008-5472.can-04-0453

Language

  • eng