de Vries, A. et al. Targeted point mutations of p53 lead to dominant-negative inhibition of wild-type p53 function. Proc. Natl Acad. Sci. USA 99, 2948-2953

Department of Biology and Center for Cancer Research, and Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Proceedings of the National Academy of Sciences (Impact Factor: 9.67). 04/2002; 99(5):2948-53. DOI: 10.1073/pnas.052713099
Source: PubMed


The p53 tumor suppressor gene is the most frequently mutated gene in human cancers, and germ-line p53 mutations cause a familial predisposition for cancer. Germ-line or sporadic p53 mutations are usually missense and typically affect the central DNA-binding domain of the protein. Because p53 functions as a tetrameric transcription factor, mutant p53 is thought to inhibit the function of wild-type p53 protein. Here, we studied the possible dominant-negative inhibition of wild-type p53 protein by two different, frequently occurring point mutations. The R270H and P275S mutations were targeted into the genome of mouse embryonic stem cells to allow the analysis of the effects of the mutant proteins expressed in normal cells at single-copy levels. In embryonic stem cells, the presence of a heterozygous point-mutated allele resulted in delayed transcriptional activation of several p53 downstream target genes on exposure to gamma irradiation. Doxorubicin-induced apoptosis was severely affected in the mutant embryonic stem cells compared with wild-type cells. Heterozygous mutant thymocytes had a severe defect in p53-dependent apoptotic pathways after treatment with gamma irradiation or doxorubicin, whereas p53-independent apoptotic pathways were intact. Together these data demonstrate that physiological expression of point-mutated p53 can strongly limit overall cellular p53 function, supporting the dominant-negative action of such mutants. Also, cells heterozygous for such mutations may be compromised in terms of tumor suppression and response to chemotherapeutic agents.

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    • "Those findings were also correlated to the decreased ability of WT TP53 to induce growth suppression and cell cycle arrest in the presence of TP53 mutant [Willis et al., 2004]. Furthermore, the dominant negative potential of two TP53 mutants (p.R270H and p.P275S, corresponding in humans to p.R273H and p.P278S, respectively) was also demonstrated in vivo, in mouse models [de Vries et al., 2002]. "
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    ABSTRACT: Loss-of-function, partial-function, altered-function, dominant-negative, temperature sensitive; interfering; contact; structural; unfolded; misfolded; dimeric; monomeric; non-cooperative; unstable; supertrans; superstable; intragenic suppressor. TP53 mutants: they are many, more than 2000 in fact, and they can be very diverse. Sporadic; germline; gain-of-function; oncogenic; rebel-angel; yin and yang; prion-like; metastasis-inducer; mediator of chemo-resistance; modifier of stemness. TP53 mutants can impact on important cancer clinical variables, in multiple, often subtle ways, as revealed by cell-based assays as well as animal models. Here we review studies investigating TP53 mutants for their effect on sequence-specific transactivation function, and especially recent findings on how TP53 mutants can exhibit gain-of-function properties. We also review reports on TP53 mutants' impact on cancer cell transcriptomes and studies with Li-Fraumeni patients trying to classify and predict phenotypes in relation to experimentally determined transcription fingerprints. Finally, we provide an example of the complexity of correlating TP53 mutant functionality to clinical variables in sporadic cancer patients. Conflicting results and limitations of experimental approaches notwithstanding, the study of TP53 mutants has provided a rich body of knowledge, mostly available in the public domain and accessible through databases, that is beginning to impact on cancer intervention strategies. This article is protected by copyright. All rights reserved.
    Human Mutation 06/2014; 35(6). DOI:10.1002/humu.22514 · 5.14 Impact Factor
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    • "Some studies showed that p53 is sequestered in the cytoplasm of mES cells, and that mES cells undergo p53-independent apoptosis in response to DNA damage [54]. Others have found that mES cells undergo p53-dependent apoptosis [55]. Different batches of sera, media, and the heterogeneity of ES cell culture could potentially explain this discrepancy. "
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    ABSTRACT: The viability and subtle developmental defects of p53 knockout mice suggest that p53 does not play major role in development. However, contradictory evidence also exists. This discrepancy mainly results from the lack of molecular and cellular mechanisms and the general fact that p53 activation requires stresses. Recent studies of p53 in mouse and human ES cells and induced pluripotent stem (iPS) cells shed new light on the mechanisms of the developmental roles of p53. This review summarizes these new studies that support the developmental roles of p53, highlights the possible underlying molecular mechanisms, and discusses the potential relationship between the developmental roles and the tumor suppressive function of p53. In summary, the molecular mechanisms underlying the developmental roles of p53 are emerging, and the developmental roles and tumor suppressive function of p53 may be closely related.
    Cell and Bioscience 10/2013; 3(1). DOI:10.1186/2045-3701-3-42 · 3.63 Impact Factor
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    • "The dominant-negative hypothesis for WT p53 inactivation in cells carrying a mutation in one of the alleles of the TP53 gene proposes that the presence of even a single mutant protein in the formation of the p53 tetramer would lead to loss-of-function of p53 [87,88]. Our group has previously proposed an alternative hypothesis for the dominant-negative effect in which WT p53 at lower concentrations would be incorporated into aggregates containing the mutant p53 (Figures 5B and 5C) [10,16]. "
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    ABSTRACT: p53 is a key protein that participates in cell-cycle control, and its malfunction can lead to cancer. This tumour suppressor protein has three main domains; the N-terminal transactivation domain, the CTD (C-terminal domain) and the core domain (p53C) that constitutes the sequence-specific DBD (DNA-binding region). Most p53 mutations related to cancer development are found in the DBD. Aggregation of p53 into amyloid oligomers and fibrils has been shown. Moreover, amyloid aggregates of both the mutant and WT (wild-type) forms of p53 were detected in tumour tissues. We propose that if p53 aggregation occurred, it would be a crucial aspect of cancer development, as p53 would lose its WT functions in an aggregated state. Mutant p53 can also exert a dominant-negative regulatory effect on WT p53. Herein, we discuss the dominant-negative effect in light of p53 aggregation and the fact that amyloid-like mutant p53 can convert WT p53 into more aggregated species, leading into gain of function in addition to the loss of tumour suppressor function. In summary, the results obtained in the last decade indicate that cancer may have characteristics in common with amyloidogenic and prion diseases.
    Bioscience Reports 07/2013; 33(4). DOI:10.1042/BSR20130065 · 2.64 Impact Factor
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