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)

Loss of heterozygosity (LOH) in chromosome region 6q27 and p53 mutations were studied to attempt to clarify the genetic etiology of ovarian cancer, with particular reference to clear cell adenocarcinoma (CCC), which has a poor prognosis. 6q27 LOH in 70 epithelial ovarian cancer patients was examined using four restriction fragment length polymorphism markers located at 6q27; p53 mutations in tumor DNA were detected using polymerase chain reaction single-strand conformation polymorphism and sequencing. 6q27 LOH was confirmed in 26 of 48 informative cases (54.2%). No differences in the incidence of 6q27 LOH were seen by histologic type; 6q27 LOH was observed in 45% (5/11) of CCCs. p53 mutations were detected in 19 of the 48 tumors (39.6%), but in only one (9%) CCC. These results suggest that a putative tumor suppressor gene involved in the onset of epithelial ovarian cancer is located at 6q27. This gene is one of the keys to clarifying the genetic etiology of epithelial ovarian cancer and particularly CCC, given the low incidence of p53 mutations in this tumor type.
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PMID:Loss of heterozygosity on chromosome 6q27 and p53 mutations in epithelial ovarian cancer. 978 20

The short arm of chromosome 17 is one of the most frequently affected chromosomal regions in lung cancers, while there is solid evidence that the p53 gene at 17p13.1 is a target for frequent 17p deletions. In the present study, we re-evaluated 17p deletions in lung cancers by conducting a detailed analysis of the minimum deleted region(s) on 17p with reference to the p53 gene status in each 100 primary lung cancer cases. In addition to the p53 locus at 17p13.1, the presence of an independent, commonly deleted region(s) at 17p13.3 was identified. Furthermore, loss of heterozygosity (LOH) at 17p13.3 was shown to be even more frequent than that at 17p13.1 and it appeared to occur in the absence of p53 mutation and/or 17p13.1 deletion. These results suggest that in addition to the p53 gene at 17p13.1, an as yet unidentified tumor suppressor gene(s) residing at 17p13.3 might play a role in lung carcinogenesis possibly in an earlier phase than the p53 gene. This would warrant future studies to identify the putative tumor suppressor gene at 17p13.3 in order to gain a better understanding of the molecular pathogenesis of this fatal disease.
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PMID:Detailed deletion mapping suggests the involvement of a tumor suppressor gene at 17p13.3, distal to p53, in the pathogenesis of lung cancers. 979 80

The ING1 gene encodes p33(ING1), a putative tumor suppressor for neuroblastomas and breast cancers, which has been shown to cooperate with p53 in controlling cell proliferation. We have isolated a novel human gene, ING1L, that potentially encodes a PHD-type zinc-finger protein highly homologous to p33(ING1). Fluorescence in situ hybridization and radiation-hybrid analyses assigned ING1L to human chromosome 4. Both ING1 and ING1L are expressed in a variety of human tissues, but we found ING1L expression to be significantly more pronounced in tumors from several colon-cancer patients than in normal colon tissues excised at the same surgical sites. Although the significance of this observation with respect to carcinogenesis remains to be established, the data suggest that ING1L might be involved in colon cancers through interference with signal(s) transmitted through p53 and p33(ING1).
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PMID:Cloning of a novel gene (ING1L) homologous to ING1, a candidate tumor suppressor. 1007 87

HeLa X human skin fibroblast hybrid cells have been developed into a model for radiation-induced neoplastic transformation of human cells. Previous studies indicate that the appearance of neoplastically transformed foci in this system is delayed for several population doublings after irradiation and appears to involve the loss of putative tumor suppressor loci on fibroblast chromosomes 11 and 14. We now show that after treatment with 7 Gy of X-rays, transformed foci initiation correlates with delayed apoptosis initiated in the progeny of the irradiated cells after 10-12 cell divisions and with reduced plating efficiency (delayed death). The cells develop classic apoptotic morphology, positive terminal deoxynucleotidyl transferase-mediated nick end labeling and phosphatidylserine (annexin V) staining, and cleavage of poly(ADP-ribose) polymerase. In addition, a delayed induction of the p53 protein and the proapoptotic Bax protein is evident over a week after radiation exposure. We propose that a delayed build-up of mitosis-dependent genomic DNA damage or a loss of genetic material over time (10-12 cell divisions postirradiation) has two relevant outcomes: (a) cell death due to the delayed induction of a p53-dependent apoptosis; and (b) neoplastic transformation of a minor subset of survivors that has lost fibroblast chromosomes 11 and 14 (tumor suppressor loci for this system) and has either evaded apoptosis or not acquired enough genetic damage to induce apoptosis. It is postulated that both phenomena result from X-ray-induced, translesion-mediated genomic instability.
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PMID:Delayed apoptotic responses associated with radiation-induced neoplastic transformation of human hybrid cells. 1046 94

A unique clinical syndrome has been described in which patients have chronic oral ulceration and autoantibodies to nuclei of stratified squamous epithelium. We have characterized the autoantibodies from patients sera and found that the major autoantigen is a 70 kDa epithelial nuclear protein. Sequencing of the cDNA for this protein, chronic ulcerative stomatitis protein, revealed it to be homologous to the p53 tumor suppressor and to the p73 putative tumor suppressor, and to be a splicing variant of the KET gene. The p53-like genes, p73 and the several KET splicing variants, are recently described genes of uncertain biologic and pathologic significance. This study provides the first clear association of a p53-like protein with a disease process.
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PMID:Characterization of an autoantigen associated with chronic ulcerative stomatitis: the CUSP autoantigen is a member of the p53 family. 1046 95

Inactivation of the P16 (INK4A)/retinoblastoma (RB) or TP53 biochemical pathway is frequent event in most human cancers. Recent evidence has shown that P14ARF binds to MDM2 leading to an increased availability of wild type TP53 protein. Functional studies also support a putative tumor suppressor gene function for p14ARF suggesting that p14ARF or p53 inactivation may be functionally equivalent in tumorigenesis. To study the relative contribution of each pathway in tumorigenesis, we analysed and compared alterations of the p16, p14ARF and p53 genes in 38 primary non-small cell lung cancers (NSCLCs) (19 adenocarcinomas and 19 squamous carcinoma). The p16 tumor suppressor gene was inactivated in 22 of 38 (58%) tumors. Twelve of these samples (31%) had homozygous deletions by microsatellite analysis; eight of them (21%) had p16 promoter hypermethylation detected by Methylation Specific PCR (MSP) and the remaining two (5%) harbored a point mutation in exon 2 by sequence analysis. The absence of P16 protein in every case was confirmed by immunohistochemistry. Fourteen of the 22 tumors with p16 inactivation also inactivated the p14ARF gene (12 with homozygous deletions extending into INK4a/ARF and two with exon 2 mutations). Mutations of p53 were found in 18 (47%) of the tumors and nine of them (50%) harbored p14ARF inactivation. Thus, an inverse correlation was not found between p14ARF and p53 genetic alterations (P=0.18; Fisher Exact Test). Our data confirm that the p16 gene is frequently inactivated in NSCLC. Assuming that 9p deletion occurs first, the common occurrence of p53 and p14ARF alterations suggests that p14ARF inactivation is not functionally equivalent to abrogation of the TP53 pathway by p53 mutation.
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PMID:Inactivation of the INK4A/ARF locus frequently coexists with TP53 mutations in non-small cell lung cancer. 1055 71

Previous studies have shown that allelic losses in a locus mapping to the chromosomal region 4p14-16 are indicative of poor prognosis in colorectal cancer. To further characterize the region involved and to confirm earlier observations, we have analyzed losses of heterozygosity (LOH) in nine microsatellite markers spanning this region in a prospective series of 181 colorectal carcinomas. The extent and the nature of the allelic imbalance were also ascertained by comparative genomic hybridization analysis of selected cases. The minimum common deleted region was confined to marker D4S2397 (LOH in 35% of the informative cases). Surrounding markers displayed LOH in 13-25% of informative cases and (other than the D4S2397 marker itself) showed a higher rate of allelic imbalances in association with mutations in the p53 tumor suppressor gene. Tumors with lymph node invasion also displayed increased rates of LOH in most markers. Regarding patient outcome, LOH solely at the D4S2397 locus was indicative of a shorter disease-free survival (P = 0.027). In consequence, two patterns of allelic loss are defined within the 4p14-16 region: (a) gross losses associated with tumor progression and probably attributable to the genomic instability related to the inactivation of the p53 tumor suppressor gene; and (b) specific losses limited to the D4S2397 locus (within an estimated fragment of 2 Mb) and associated with increased tumor aggressiveness. The presence of one or more putative tumor suppressor genes in this region is postulated.
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PMID:Prospective assessment of allelic losses at 4p14-16 in colorectal cancer: two mutational patterns and a locus associated with poorer survival. 1058 58

Recently, p73, a protein with structural and functional similarities to p53, an extensively studied tumor suppressor gene, has been cloned. After being mapped to the chromosomal region 1p35-1p36, it has been postulated to act as a tumor suppressor gene, too, as this region is altered in several human malignancies. Deletions of the short arm of chromosome 1 have frequently been described in multiple myeloma (MM) whereas structural abnormalities of the 17p13 region including p53 are rare events in this disease. Since it has been proposed that especially neoplasias lacking p53 alterations might show a loss of heterozygosity at 1p35-1p36, we studied the frequency of p53 and p73 deletions in bone marrow mononuclear cells of 68 patients with MM, two patients with monoclonal gammopathy of undetermined significance and four patients with plasma cell leukemia. Dual-color fluorescence in situ hybridization (FISH) for p53 and p73 was performed using commercially available DNA probes for 17p13.3 and the microsatellite marker D1Z2, respectively. Centromeric DNA probes served to distinguish gene deletions from whole chromosome losses. In contrast to recently published FISH results, we only detected heterozygous p53 deletions in eight out of the 74 patients, three of them showing a monosomy 17. Heterozygous deletions of the D1Z2 region at 1p36 were found in six cases with one patient having a monosomy 1. Neither homozygous deletions of either chromosomal region nor nullisomies 1 or 17 could be detected. These results argue against a major role of p73 deletions in MM. As MM patients with 1p structural abnormalities have a significantly poorer survival rate than those with normal karyotypes, the role of other putative tumor suppressor genes located at the chromosomal region 1p36 in the pathogenesis of MM has to be determined.
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PMID:Analysis of p73 and p53 gene deletions in multiple myeloma. 1060 35

Genetic aberrations associated with the development of extranodal high-grade large B-cell lymphoma originating in the stomach have not been fully identified yet. We analyzed 31 such lymphomas using 73 microsatellite markers for allelic imbalance and microsatellite instability. The highest frequency (42%) of loss of heterozygosity (LOH) was found on the long arm of chromosome 6. We identified 2 LOH hot spots on 6q21-22.1 and 6q23.3-25, flanked by markers D6S246-D6S261 and D6S310-D6S441, respectively, containing putative tumor suppressor genes (TSGs). These 6q aberrations were found to be the sole allelic imbalance in 1 patient only; they were mostly accompanied by additional abnormalities. Several known TSGs, namely, the APC, p15/p16, p53, and DCC genes, were found to suffer frequent LOH during lymphomagenesis. LOH was also detected in regions containing putative TSGs on 7q and 13q14. Frequent amplification of genomic material was found in the 2p, 3q27 at the BCL-6 gene locus, 6p, 7q, 11q23-24 at the MLL gene locus, and 18q regions. Analysis of the pattern of occurrence of these aberrations revealed an association of the amplification of the MLL gene region with LOH at the p53 locus (P =.02). Only low frequency of microsatellite instability (MSI) was detected in these lymphomas and MSI incidence increased with age (P =.01). Karyotypic instability thus plays the main role in the development of gastric high-grade large B-cell lymphoma. Common genetic aberrations responsible for lymphomagenesis are deletions of 6q, loss of p53, and amplification of the 3q27 and the MLL gene regions. (Blood. 2000;95:1180-1187)
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PMID:Genetic aberrations common in gastric high-grade large B-cell lymphoma. 1066 88

Barrett's esophagus carries a 30- to 100-fold increased risk of adenocarcinoma, which is thought to develop via a metaplasia-dysplasia-carcinoma progression. A common genetic abnormality detected in Barrett's adenocarcinoma is loss of heterozygosity (LOH) at the sites of known or putative tumor suppressor genes, of which there are at least 9 associated with esophageal adenocarcinoma. The aim of this study was to identify at which histological stage of carcinogenesis LOH at these sites occur. Microdissection of multiple paraffin-embedded tissue blocks from 17 esophagogastrectomy specimens of adenocarcinoma arising in Barrett's esophagus yielded areas of metaplasia, low-, intermediate- and high-grade dysplasia, and carcinoma. LOH analysis of microdissected tissues was performed using a double polymerase chain reaction technique with 11 microsatellite primers shown previously to have LOH in at least 30% of esophageal adenocarcinomas. Identical LOH was detected in premalignant and malignant tissues in 4 of 17 patients, and was located at 5q21-q22 (D5S346 primer), 17p11.1-p12 (TCF2 primer), 17p13.1 (TP53 primer), 18q21.1 (detected in colon cancer tumor suppressor gene [DCC] primer), and 18q23-qter (D18S70 primer). These results suggest that LOH at the sites of the DCC, adenomatous polyposis coli (APC), and TP53 tumor suppressor genes occur before the development of adenocarcinoma in Barrett's esophagus, and so merit further study as potential biomarkers of neoplastic progression in patients with Barrett's esophagus undergoing endoscopic and histological surveillance.
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PMID:LOH at the sites of the DCC, APC, and TP53 tumor suppressor genes occurs in Barrett's metaplasia and dysplasia adjacent to adenocarcinoma of the esophagus. 1066 31


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