Tumor suppression in the absence of p53-mediated cell-cycle arrest, apoptosis, and senescence.
Cell-cycle arrest, apoptosis, and senescence are widely accepted as the major mechanisms by which p53 inhibits tumor formation. Nevertheless, it remains unclear whether they are the rate-limiting steps in tumor suppression. Here, we have generated mice bearing lysine to arginine mutations at one (p53(K117R)) or three (p53(3KR); K117R+K161R+K162R) of p53 acetylation sites. Although p53(K117R/K117R) cells are competent for p53-mediated cell-cycle arrest and senescence, but not apoptosis, all three of these processes are ablated in p53(3KR/3KR) cells. Surprisingly, unlike p53 null mice, which rapidly succumb to spontaneous thymic lymphomas, early-onset tumor formation does not occur in either p53(K117R/K117R) or p53(3KR/3KR) animals. Notably, p53(3KR) retains the ability to regulate energy metabolism and reactive oxygen species production. These findings underscore the crucial role of acetylation in differentially modulating p53 responses and suggest that unconventional activities of p53, such as metabolic regulation and antioxidant function, are critical for suppression of early-onset spontaneous tumorigenesis.
Institute for Cancer Genetics, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.
Tongyuan
T
Li
Ning
N
Kon
Le
L
Jiang
Minjia
M
Tan
Thomas
T
Ludwig
Yingming
Y
Zhao
Richard
R
Baer
Wei
W
Gu
D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis; D059447:Cell Cycle Checkpoints; D016922:Cellular Senescence; D005347:Fibroblasts / Q000378:metabolism; D055879:Gene Knock-In Techniques; D006801:Humans; D008223:Lymphoma / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D009369:Neoplasms / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D013953:Thymus Neoplasms / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism*
D016159:Tumor Suppressor Protein p53