Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04637 (p53)
 77,613 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Nucleophosmin (NPM) is a nucleocytoplasmic shuttling protein involved in leukemia-associated chromosomal translocations, and it regulates the alternate reading frame (ARF)-p53 tumor-suppressor pathway. Recently, it has been demonstrated that mutations of the NPM1 gene alter the protein at its C-terminal, causing its cytoplasmic localization. Cytoplasmic NPM was detected in 35% of adult patients with primary non-French-American-British (FAB) classification M3 acute myeloid leukemia (AML), associated mainly with normal karyotype. We evaluated the prevalence of the NPM1 gene mutation in non-M3 childhood AML patients enrolled in the ongoing Associazione Italiana di Ematologia e Oncologia Pediatrica (AIEOP-AML02) protocol in Italy. NPM1 mutations were found in 7 (6.5%) of 107 successfully analyzed patients. NPM1-mutated patients carried a normal karyotype (7/26, 27.1%) and were older in age. Thus, the NPM1 mutation is a frequent abnormality in AML patients without known genetic marker; the mutation may represent a new target to monitor minimal residual disease in AML and a potential candidate for alternative and targeted treatments.
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PMID:Nucleophosmin mutations in childhood acute myelogenous leukemia with normal karyotype. 1587 Jan 72

Recently, somatic mutations of the nucleophosmin gene (NPM1), which alter the subcellular localization of the product, have been reported in acute myeloid leukemia (AML). We analyzed the clinical significance of NPM1 mutations in comparison with cytogenetics, FLT3, NRAS, and TP53 mutations, and a partial tandem duplication of the MLL gene (MLL-TD) in 257 patients with AML. We found NPM1 mutations, including 4 novel sequence variants, in 64 of 257 (24.9%) patients. NPM1 mutations were associated with normal karyotype and with internal tandem duplication (ITD) and D835 mutations in FLT3, but not with other mutations. In 190 patients without the M3 French-American-British (FAB) subtype who were treated with the protocol of the Japan Adult Leukemia Study Group, multivariate analyses showed that the NPM1 mutation was a favorable factor for achieving complete remission but was associated with a high relapse rate. Sequential analysis using 39 paired samples obtained at diagnosis and relapse showed that NPM1 mutations were lost at relapse in 2 of the 17 patients who had NPM1 mutations at diagnosis. These results suggest that the NPM1 mutation is not necessarily an early event during leukemogenesis or that leukemia clones with NPM1 mutations are sensitive to chemotherapy.
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PMID:Clinical characteristics and prognostic implications of NPM1 mutations in acute myeloid leukemia. 1599 85

C-terminal somatic mutations in nucleophosmin (NPM), a nucleolar shuttling protein that binds p53 and p19(Arf), were recently described in karyotypically normal acute myeloid leukaemia (AML). We analysed primary marrow samples from 150 patients with various chronic myeloid disorders for mutations in the NPM1 gene encoding NPM. NPM1 mutations (tetranucleotide duplication) were detected in three patients, all of whom had chronic myelomonocytic leukaemia (CMML) and a short (<1 year) survival, with rapid progression to overt AML. All other patients were NPM1-wild type in the region analysed. In conclusion, C-terminal NPM mutations are uncommon in chronic myeloid neoplasia, but if present may represent an evolving leukaemic clone.
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PMID:C-terminal nucleophosmin mutations are uncommon in chronic myeloid disorders. 1670 39

Nucleophosmin (NPM) is a nucleolar phosphoprotein that plays multiple roles in ribosome assembly and transport, cytoplasmic-nuclear trafficking, centrosome duplication and regulation of p53. In hematological malignancies, the NPM1 gene is frequently involved in chromosomal translocation, mutation and deletion. The NPM1 gene on 5q35 is translocated with the anaplastic lymphoma kinase (ALK) gene in anaplastic large cell lymphoma with t(2;5). The MLF1 and RARA genes are fused with NPM1 in myelodysplastic syndrome and acute myeloid leukemia (AML) with t(3;5) and acute promyelocytic leukemia with t(5;17), respectively. In each fused protein, the N-terminal NPM portion is associated with oligomerization of a partner protein leading to altered signal transduction or transcription. Recently, mutations of exon 12 have been found in a significant proportion of de novo AML, especially in those with a normal karyotype. Mutant NPM is localized aberrantly in the cytoplasm, but the molecular mechanisms for leukemia remain to be studied. Studies of knock-out mice have revealed new aspects regarding NPM1 as a tumor-suppressor gene. This review focuses on the clinical significance of the NPM1 gene in hematological malignancies and newly discovered roles of NPM associated with oncogenesis.
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PMID:Nucleophosmin: a versatile molecule associated with hematological malignancies. 1698 70

Acute myeloid leukemia (AML) is a heterogeneous group of neoplastic disorders with great variability in clinical course and response to therapy, as well as in the genetic and molecular basis of the pathology. Major advances in the understanding of leukemogenesis have been made by the characterization and the study of acquired cytogenetic abnormalities, particularly reciprocal translocations observed in AML. Besides these major cytogenetic abnormalities, gene mutations also constitute key events in AML pathogenesis. In this review, we describe the contribution of known gene mutations to the understanding of AML pathogenesis and their clinical significance. To gain more insight in this understanding, we clustered these alterations in three groups: (1) mutations affecting genes that contribute to cell proliferation (FLT3, c-KIT, RAS, protein tyrosine standard phosphatase nonreceptor 11); (2) mutations affecting genes involved in myeloid differentiation (AML1 and CEBPA) and (3) mutations affecting genes implicated in cell cycle regulation or apoptosis (P53, NPM1). This nonexhaustive review aims to show how gene mutations interact with each other, how they contribute to refine prognosis and how they can be useful for risk-adapted therapeutic management of AML patients.
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PMID:Cooperating gene mutations in acute myeloid leukemia: a review of the literature. 1828 31

Chromosome loss or gain is associated with a large number of solid cancers, providing genomic plasticity and thus adaptability to cancer cells. Numerical centrosome abnormalities arising from centrosome over-duplication or failed cytokinesis are a recognized cause of aneuploidy. In higher eukaryotic cells, the centrosome duplicates only once per cell cycle to ensure the formation of a bipolar mitotic spindle that orchestrates the balanced distribution of the sister chromatids to the respective daughter cells. Here we delineate the events that allow abnormal centrosome duplication, resulting in mitotic errors and incorrect chromosome segregation in cells with sustained cyclin-dependent kinase (CDK) activity. We have identified NPM1 as a substrate for CDK6 activated by the Kaposi's sarcoma herpesvirus (KSHV) D-type cyclin and shown that p53-driven apoptosis occurs downstream of NPM1 phosphorylation as a checkpoint mechanism that prevents accumulation of cells with supernumerary centrosomes. Our findings provide evidence that abnormal chromosome segregation in KSHV-infected cells is a direct consequence of NPM1 phosphorylation and predict that genomic instability is an inevitable consequence of latent KSHV infection.
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PMID:p53-Driven apoptosis limits centrosome amplification and genomic instability downstream of NPM1 phosphorylation. 1845 40

Mutations affecting NPM1 (nucleophosmin) are the most common genetic lesions found in acute myeloid leukemia (AML). NPM1 is one of the most abundant proteins found in the nucleolus and has links to the MDM2/p53 tumor suppressor pathway. A distinctive feature of NPM1 mutants in AML is their aberrant localization to the cytoplasm of leukemic cells. This mutant phenotype is the result of the substitution of several C-terminal residues, including one or two conserved tryptophan residues, with a leucine-rich nuclear export signal. The exact molecular mechanism underlying the loss of nucleolar retention, and the role of the tryptophans, remains unknown. In this study we have determined the structure of an independently folded globular domain in the C terminus of NPM1 using NMR spectroscopy, and we report that the conserved tryptophans are critical for structure. This domain is necessary for the nucleolar targeting of NPM1 and is disrupted by mutations in AML with cytoplasmic NPM1. Furthermore, we identify conserved surface-exposed lysine residues that are functionally rather than structurally important for nucleolar localization. This study provides new focus for efforts to understand the pathogenesis of AML with cytoplasmic NPM1 and may be used to aid the design of small molecules that target the C-terminal domain of NPM1 to act as novel anti-proliferative and anti-leukemia therapeutics.
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PMID:Structural consequences of nucleophosmin mutations in acute myeloid leukemia. 1851 15

Loss of p53 -- a tumor suppressor gene located on the short arm of chromosome 17 (band 17p13.1) -- was detected in 105 out of 2272 (5%) adult acute myeloid leukemia (AML) patients who took part in the Study Alliance Leukemia AML96 and AML2003 multi center trials. There were 85 patients with 17p (p53) deletion with multiple aberrations and 20 patients with a 17p (p53) deletion as single aberration or with only one additional chromosomal abnormality. None of the p53-deleted patients displayed additional low-risk aberrations, like t(8;21) or inv(16). Significant positive association between p53 deletion and other high-risk factors was identified for del(5q) (P<0.001), -5 (P<0.001) and -7 (P<0.05). The molecular risk factors FLT3-ITD and NPM1 mutation showed an inverse correlation to the p53 deletion in complex aberrant patients (P<0.001). The multivariate analysis revealed p53 deletion without multiple aberrations as an independent negative prognostic factor for disease-free survival (P<0.001), relapse risk (P=0.028) and overall survival (P<0.001). Thus, the single p53 deletion should be considered as a high-risk aberration for future risk-adapted treatment strategies in AML.
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PMID:The prognostic impact of 17p (p53) deletion in 2272 adults with acute myeloid leukemia. 1915 74

Acute myeloid leukemia (AML) has been thought to be the consequence of two broad complementation classes of mutations: class I and class II. However, overlap-mutations between them or within the same class and the position of TP53 mutation are not fully analyzed. We comprehensively analyzed the FLT3, cKIT, N-RAS, C/EBPA, AML1, MLL, NPM1, and TP53 mutations in 144 newly diagnosed de novo AML. We found 103 of 165 identified mutations were overlapped with other mutations, and most overlap-mutations consisted of class I and class II mutations. Although overlap-mutations within the same class were found in seven patients, five of them additionally had the other class mutation. These results suggest that most overlap-mutations within the same class might be the consequence of acquiring an additional mutation after the completion both of class I and class II mutations. However, mutated genes overlapped with the same class were limited in N-RAS, TP53, MLL-PTD, and NPM1, suggesting the possibility that these irregular overlap-mutations might cooperatively participate in the development of AML. Notably, TP53 mutation was overlapped with both class I and class II mutations, and associated with morphologic multilineage dysplasia and complex karyotype. The genotype consisting of complex karyotype and TP53 mutation was an unfavorable prognostic factor in entire AML patients, indicating this genotype generates a disease entity in de novo AML. These results collectively suggest that TP53 mutation might be a functionally distinguishable class of mutation.
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PMID:Comprehensive analysis of cooperative gene mutations between class I and class II in de novo acute myeloid leukemia. 1930 22

The p14ARF protein activates the p53 tumor suppressor by binding to and inhibiting its negative regulator HDM-2. We have studied the prognostic impact of p14ARF in acute myeloid leukemia (AML). Leukemic cells from 57 adult patients with normal karyotype de novo AML were analyzed for p14ARF mRNA expression level using real-time polymerase chain reaction (RT-PCR). We also tested the effect of conventional anti-leukemic drugs and the mutant p53-targeting small molecule PRIMA-1 in vitro. Patients whose cells expressed more p14ARF mRNA than the 75th percentile (0.26) had significantly better survival compared with those expressing lower levels, 61 vs. 30% 3-year survival (p = 0.046). The difference remained significant also when NPM1/FLT3 status was considered. The mean effects of all the tested conventional anti-leukemic drugs were greater in leukemic cell samples expressing p14ARF mRNA >or= 0.26, but the differences were not statistically significant. In contrast, PRIMA-1 had a significantly greater effect on leukemic cell samples with low levels of p14ARF mRNA. We conclude that low levels of p14ARF mRNA in leukemic cells from patients with normal karyotype AML is associated with poor prognosis. Treatment with drugs targeting p53 may be a future possibility to improve outcome for these patients.
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PMID:Low p14ARF expression in de novo acute myeloid leukemia with normal karyotype is associated with poor survival. 1981 25


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