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)

We report a constitutional mutation of codon 273 in exon 8 of the p53 gene. The affected individual has developed multiple independent benign and malignant tumours (tricholemmoma of the scalp, multiple trichoepitheliomata of the face, osteosarcoma of the ovary, bilateral breast cancer, malignant fibrous histiocytoma of the thigh and endometrial adenocarcinoma) and belongs to a family with some, but not all, features of the Li-Fraumeni syndrome. The mutation, found in both blood lymphocyte and tumour specimens, is a cytosine to thymine transition at codon 273, resulting in an amino acid change from arginine to cysteine. The mother and sister of the index case both died of tumours at an early age. We have demonstrated that formalin-preserved material from these tumours contains the same C-->T mutation at codon 273, indicating that this mutation has probably been transmitted through the germline. All tumours from the index case, both benign and malignant, showed immunohistochemical positivity with four antibodies to the p53 protein. Positive staining was also seen in scattered nuclei of morphologically normal epidermal keratinocytes and pilosebaceous cells, but not in lymphocytes or other morphologically normal cells from the index case. However, a similar staining pattern in apparently normal tissue was also observed in 13/48 sections from other individuals with various skin conditions (melanocytic naevi, psoriasis and normal skin adjacent to malignant melanoma and fibrous histiocytomas), suggesting that this pattern of p53 staining may not be unique to individuals with constitutional p53 mutations.
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PMID:Constitutional mutation in exon 8 of the p53 gene in a patient with multiple primary tumours: molecular and immunohistochemical findings. 847 49

Alterations of the TP53 tumor suppressor gene are present in various human malignancies and in the dominantly inherited Li-Fraumeni syndrome. Recently, a cell cycle checkpoint pathway involving p53 and GADD45 has been identified as defective in ataxia-telangiectasia. Using single strand conformation polymorphism analysis of PCR products, we looked for TP53 mutations in DNA of patients with AT. We did not find any mutation in 6 patients, suggesting that TP53 mutations are not directly involved in the cancer susceptibility observed in AT.
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PMID:Lack of mutations in the P53 gene exons 5 to 8 in ataxia-telangiectasia. 850 Jan 1

Li-Fraumeni syndrome (LFS) is an autosomal dominant disorder that predisposes individuals to multiple forms of cancer including breast carcinoma, soft tissue sarcoma, osteosarcoma, leukemia and adrenocortical carcinoma. These diverse tumor types develop at unusually early ages. Analysis of the tumor suppressor gene p53 in family members with LFS have demonstrated that germline mutations in the p53 gene were present in most of the LFS family tested so far. Furthermore, germline p53 mutations were also found in cancer-prone individuals which were not indicative of the LFS.
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PMID:Germline mutations of the p53 tumor-suppressor gene in cancer-prone families: a review. 851 Oct 38

Li-Fraumeni syndrome(LFS) is an autosomal dominant disorder that predisposes individuals to multiple forms of cancer including breast cancer, soft tissue sarcoma, brain tumor, osteosarcoma, leukemia, and adrenocortical carcinoma. Recently, germ-line mutation of the p53 tumor suppressor gene has been implicated in this familial disorder. We report a case of a 25-year old woman who presented with bilateral breast cancer and uterine leiomyoma. Her mother had died of early-onset bilateral breast cancer. And her younger sister had breast carcinoma as well, which was identified at the age of 22, indicating her strong familial history. To test for the presence of the p53 germ-line mutation, we analyzed the genomic DNA from the peripheral blood of the proband and her sister by PCR-SSCP analysis of exon 5 through exon 8 of the p53 gene. As a result, a p53 mutation in exon 7 was detected in an allele, and it was shared with her sister as the same pattern. Sequencing analysis determined the altered nucleotide at codon 248(CGG > TGG) which is one of the most frequent mutation sites related to LFS. Therefore, this patient has the most consistent characteristic features of LFS phenotype and it is believed that this case is the first report of a family with Li-Fraumeni syndrome carrying the p53 germ-line mutation in Korea.
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PMID:The first documentation of Li-Fraumeni syndrome in Korea. 852 48

The Li-Fraumeni syndrome was initially recognized through clinical observations at the bed side, which was followed by epidemiological studies. Children suffering from rhabdomyosarcoma were shown to have two or more of six forms of cancer in their parents, grandparents and other relatives, indicating cancer family syndrome. This syndrome has been shown to involve tumor suppressor gene p53 mutations in the germ-line. The patients in the family most often have a proband with soft tissue sarcoma or osteosarcoma, and relatives with breast cancer, brain tumor, leukemia and adrenocortical cancer. Members of the family also appear to be at risk for developing second independent malignancies during their life span. Recommendations on predictive testing for germ line p53 mutations among cancer-prone individuals have been made by the subcommittees, which were sponsored by National Cancer Institute and the National Center for Human Genome Research.
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PMID:[Li-Fraumeni syndrome]. 853 47

Epidemiological studies on intracranial tumors have suggested that the observed familial aggregation of a proportion of gliomas may be due to inherited predisposition to their development. In the Li-Fraumeni syndrome (LFS) associated with germ-line mutations of the p53 gene, nervous-system tumors are observed with increased frequency. However, the contribution of germ-line p53 mutation to the incidence of brain tumors has not been investigated. In order to address this point, we have performed 2 independent investigations. First, we have examined an unselected series of brain tumors. Whenever the presence of a p53 mutation in the tumor was observed, the possible germ-line origin of the mutation was investigated. Germ-line p53 mutations were also analyzed in constitutional DNA of patients with gliomas that had been selected for an unusual personal or familial history of cancer. Germ-line p53 mutations were detected in 1 out of 80 unselected cases and in 3 out of 15 selected cases (20%). We conclude that germ-line p53 mutation may contribute to a small fraction of gliomas that develop in the general population. The presence of a personal or familial history of cancer in a patient with glioma should prompt the search for a germ-line p53 mutation. However, the low frequency of p53 germ-line mutation suggests that alterations of this gene may not account for most familial cases of gliomas.
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PMID:Incidence of germ-line p53 mutations in patients with gliomas. 855 Feb 39

Proliferating-cell nuclear antigen (PCNA) is a DNA damage-inducible protein that performs an essential function in DNA replication and repair as an auxiliary factor for DNA polymerases delta and epsilon. Examination of the human PCNA promoter DNA sequence revealed a site with homology to the consensus DNA sequence bound by p53. PCNA promoter fragments with this site intact bound p53 in vitro and were transcriptionally activated by wild-type p53 in transient expression assays in SAOS-2 cells. The resident p53-binding site could be functionally substituted by a previously described p53-binding site from the ribosomal gene cluster. A plasmid expressing a mutated version of p53 derived from a patient with Li-Fraumeni syndrome failed to activate the PCNA promoter in the cotransfection assay. In different cell types, activation of the PCNA promoter by the p53-binding sequence correlated with the status of p53. Activation of the PCNA promoter by wild-type p53 depends upon the level of p53 expression. This concentration dependence and cell type specificity reconciles the observations presented here with prior results indicating that wild-type p53 represses the PCNA promoter. These findings provide a mechanism whereby p53 modulates activation of PCNA expression as a cellular response to DNA damage.
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PMID:Transcriptional activation of the human proliferating-cell nuclear antigen promoter by p53. 857 Jun 55

Mutation of the p53 gene is among the most common lesions in a variety of human tumors, including those of the central nervous system. In most instances, mutation of one p53 allele is followed by loss of the remaining wild-type allele, resulting in cells with a complete absence of functional wild-type p53 protein. However, in some situations, such as at initiation of spontaneously arising gliomas or as the germline configuration of patients with the Li-Fraumeni syndrome, cells clearly carry both wild-type and mutant p53 alleles. These observations lead to the hypothesis that p53 mutations can give rise to loss of tumor suppressor functions as well as to gain of oncogenic transformation capabilities. In this review, we define the types of mutations that occur in the p53 gene in various glial tumors, contrast that with the spectra described in other human tumor types, and discuss the biochemistry and physiology of the p53 protein and its ability to regulate and be regulated by other gene products. We use this information to propose roles for p53 in the initiation and progression of human gliomas.
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PMID:The p53 gene and its role in human brain tumors. 858 66

Dermal fibroblast strains cultured from affected members of a cancer-prone family with Li-Fraumeni syndrome (LFS) harbor a point mutation in one allele of the p53 tumor suppressor gene, resulting in loss of normal p53 function. In this study we have examined the ability of these p53-deficient strains to carry out the long-patch mode of excision repair, mediated by DNA polymerases delta and epsilon, after exposure to 60Co gamma radiation or far ultraviolet (UV) (chiefly 254 nm) light. Repair was monitored by incubation of the irradiated cultures in the presence of aphidicolin (apc) or 1-beta-D-arabinofuranosylcytosine (araC), each a specific inhibitor of long-patch repair, followed by measurement of drug-induced DNA strand breaks (reflecting non-ligated strand incision events) by alkaline sucrose velocity sedimentation. The LFS strains displayed deficient repair capacity in response to both gamma rays and UV light. The repair anomaly in UV-irradiated LFS cultures was manifested not only in the overall genome, but also in the transcriptionally active, preferentially repaired c-myc gene. Using autoradiography we also assessed unscheduled DNA synthesis (UDS) after UV irradiation and found this conventional measure of repair replication to be deficient in LFS strains. Moreover, both apc and araC decreased the level of UV-induced UDS by approximately 75% in normal cells, but each had only a marginal effect on LFS cells. We further demonstrated that the LFS strains are impaired in the recovery of both RNA and replicative DNA syntheses after UV treatment, two molecular anomalies of the DNA repair deficiency disorders xeroderma pigmentosum and Cockayne's syndrome. Together these results imply a critical role for wild-type p53 protein in DNA polymerase delta/epsilon-mediated excision repair, both the mechanism operating on the entire genome and that acting on expressed genes.
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PMID:Faulty DNA polymerase delta/epsilon-mediated excision repair in response to gamma radiation or ultraviolet light in p53-deficient fibroblast strains from affected members of a cancer-prone family with Li-Fraumeni syndrome. 862 79

We investigated the frequency of p53 mutations in 19 pediatric cases of therapy-related leukemia or myelodysplastic syndrome. Eleven children presented with acute myeloid leukemia, one with mixed-lineage leukemia, two with acute lymphoblastic leukemia, and five with myelodysplasia at times ranging from 11 months to 9 years after a primary cancer diagnosis. The primary cancers, which included 11 solid tumors and eight leukemias, were treated with various combinations of DNA topoisomerase II inhibitors, alkylating agents, or irradiation. Leukemic or myelodysplastic marrows were screened for possible mutations by single-strand conformation polymorphism (SSCP) analysis of p53 exons 4 to 8. The only observed mutation was an inherited 2-basepair deletion at codon 209 in exon 6 that would shift the open reading frame, create a premature termination codon, and foreshorten the resultant protein. Prior therapy in this patient included DNA topoisomerase II inhibitors, alkylating agents, and irradiation. The secondary leukemia presented as myelodysplasia with monosomies of chromosomes 5 and 7 and abnormalities of chromosome 17. Although the primary cancer was an embryonal rhabdomyosarcoma and there was a family history of cancer, the case did not fulfill the clinical criteria for Li-Fraumeni syndrome. This study suggests that germline p53 mutations may predispose some children to therapy-related leukemia and myelodysplasia, but that p53 mutations otherwise are infrequent in this setting.
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PMID:The p53 gene in pediatric therapy-related leukemia and myelodysplasia. 863 98


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