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P53-deficient cells rely on ATM- and ATR-mediated checkpoint signaling through the p38MAPK/MK2 pathway for survival after DNA damage.

ABSTRACT: In response to DNA damage, eukaryotic cells activate ATM-Chk2 and/or ATR-Chk1 to arrest the cell cycle and initiate DNA repair. We show that, in the absence of p53, cells depend on a third cell-cycle checkpoint pathway involving p38MAPK/MK2 for cell-cycle arrest and survival after DNA damage. MK2 depletion in p53-deficient cells, but not in p53 wild-type cells, caused abrogation of the Cdc25A-mediated S phase checkpoint after cisplatin exposure and loss of the Cdc25B-mediated G2/M checkpoint following doxorubicin treatment, resulting in mitotic catastrophe and pronounced regression of murine tumors in vivo. We show that the Chk1 inhibitor UCN-01 also potently inhibits MK2, suggesting that its clinical efficacy results from the simultaneous disruption of two critical checkpoint pathways in p53-defective cells.

SUBMITTER: Reinhardt HC

PROVIDER: S-EPMC2742175 | biostudies-literature | 2007 Feb

REPOSITORIES: biostudies-literature

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p53-deficient cells rely on ATM- and ATR-mediated checkpoint signaling through the p38MAPK/MK2 pathway for survival after DNA damage.

Reinhardt H Christian HC Aslanian Aaron S AS Lees Jacqueline A JA Yaffe Michael B MB

Cancer cell 20070201 2

In response to DNA damage, eukaryotic cells activate ATM-Chk2 and/or ATR-Chk1 to arrest the cell cycle and initiate DNA repair. We show that, in the absence of p53, cells depend on a third cell-cycle checkpoint pathway involving p38MAPK/MK2 for cell-cycle arrest and survival after DNA damage. MK2 depletion in p53-deficient cells, but not in p53 wild-type cells, caused abrogation of the Cdc25A-mediated S phase checkpoint after cisplatin exposure and loss of the Cdc25B-mediated G2/M checkpoint fol ...[more]

PMID: 17292828

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