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Cooperative functions of Chk1 and Chk2 reduce tumour susceptibility in vivo
Author(s) -
Niida Hiroyuki,
Murata Kazuhiro,
Shimada Midori,
Ogawa Kumiko,
Ohta Kumiko,
Suzuki Kyoko,
Fujigaki Hidetsugu,
Khaw Aik Kia,
Banerjee Birendranath,
Hande M Prakash,
Miyamoto Tomomi,
Miyoshi Ichiro,
Shirai Tomoyuki,
Motoyama Noboru,
Delhase Mireille,
Appella Ettore,
Nakanishi Makoto
Publication year - 2010
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1038/emboj.2010.218
Subject(s) - biology , in vivo , computational biology , cancer research , genetics
Although the linkage of Chk1 and Chk2 to important cancer signalling suggests that these kinases have functions as tumour suppressors, neither Chk1 +/− nor Chk2 −/− mice show a predisposition to cancer under unperturbed conditions. We show here that Chk1 +/− Chk2 −/− and Chk1 +/− Chk2 +/− mice have a progressive cancer‐prone phenotype. Deletion of a single Chk1 allele compromises G2/M checkpoint function that is not further affected by Chk2 depletion, whereas Chk1 and Chk2 cooperatively affect G1/S and intra‐S phase checkpoints. Either or both of the kinases are required for DNA repair depending on the type of DNA damage. Mouse embryonic fibroblasts from the double‐mutant mice showed a higher level of p53 with spontaneous DNA damage under unperturbed conditions, but failed to phosphorylate p53 at S23 and further induce p53 expression upon additional DNA damage. Neither Chk1 nor Chk2 is apparently essential for p53‐ or Rb‐dependent oncogene‐induced senescence. Our results suggest that the double Chk mutation leads to a high level of spontaneous DNA damage, but fails to eliminate cells with damaged DNA, which may ultimately increase cancer susceptibility independently of senescence.