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)

Genetic polymorphisms of aldehyde dehydrogenase 2 (ALDH2) and cytochrome P450 2E1 (CYP2E1) have been shown to influence the degree of genetic damage in Taiwanese workers exposed to the carcinogen - vinyl chloride(VC). Certain French VC workers have been found to express biomarkers of mutant forms of cancer-related proteins (ras-p21 and p53) that have been related to their exposure. ALDH2 and CYP2E1 polymorphisms were investigated in 211 of these workers in an attempt to correlate differences in VC metabolic capacity with differences in the presence of these biomarkers. All of the workers were found to have the normal, wild-type ALDH2 gene, and none of them were found to be homozygous for the variant CYP2E1 allele. Sixteen workers were found to be heterozygous for the variant CYP2E1 allele. After adjusting for age, smoking, drinking and cumulative VC exposure, the odds ratio for the presence of either the mutant ras-p21 or the mutant p53 biomarker in these heterozygous workers was found to be statistically significantly increased in comparison to their homozygous, wild-type counterparts (OR = 5.05; 95% CI = 1.10-23.25). However, as opposed to the case in Taiwanese workers, these polymorphisms are relatively uncommon, and thus differences in ALDH2 and CYP2E1 can account for only a small proportion of the variability in mutagenic response to VC exposure in a Caucasian population.
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PMID:Polymorphisms for vinyl chloride metabolism in French vinyl chloride workers. 1270 18

We have recently demonstrated a significant dose-response relationship between vinyl chloride exposure and mutant p53 biomarkers in humans. The aim of this study was to examine a common polymorphism in the DNA repair gene XRCC1 as a potential biomarker of susceptibility modifying this relationship, consistent with the known mechanism of production of p53 mutations via vinyl chloride-induced etheno-DNA adducts, which are repaired by XRCC1. A cohort of 211 French vinyl chloride workers were genotyped for the XRCC1 codon 399 polymorphism (CGG>CAG; Arg>Gln). Among the homozygous Arg-Arg individuals, 34% were biomarker positive compared with 47% in the heterozygous Arg-Gln individuals (adjusted odds ratio 1.73, 95% CI0.93-3.22) and 66% in the homozygous Gln-Gln individuals (adjusted odds ratio 3.95, 95% CI 1.68-9.28), with a significant trend for increasing Gln allele dosage (p=0.002). These preliminary results suggest that a common polymorphism in a DNA repair gene can be an important biomarker of susceptibility for chemically induced genetic damage.
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PMID:A common polymorphism in XRCC1 as a biomarker of susceptibility for chemically induced genetic damage. 1460 24

The aim of the study was to estimate the possible use of plasma anti-p53 antibodies as marker premature of cancerogenesis. The study carried on 167 male subject exposed to vinyl chloride (CV) (cumulative concentration ranged from 4 to 2823 ppm) tested anti-p53 positive in 5 cases (3.9%), all distributed in the high exposure group (> 1000 ppm); No subject in the control group tested positive. There was a significant association. between cumulative VC exposure concentration (P < 0.002) and positive anti-p53 expression. In summary, the study support a significant relationship between plasma anti-p53 and VC only for heavy exposure. The authors assume the existence of a threshold limit to the effectiveness.
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PMID:[Anti-p53 antibodies as markers of carcinogenesis in exposures to vinyl chloride]. 1497 67

Mutational incidence and spectra for genes examined in both human and mouse lung and liver tumors were analyzed using the National Institute of Environmental Health Sciences (NIEHS) Genetic Alterations in Cancer (GAC) knowledge system. GAC is a publicly available, web-based system for evaluating data obtained from peer-reviewed studies of genetic changes in tumors associated with exposure to chemical, physical, or biological agents, as well as spontaneous tumors. In mice, mutations in Kras2 and Hras-1 were the most common events reported for lung and liver tumors, respectively, whether chemically induced or spontaneous. There was a significant difference in Kras2 mutation incidence for spontaneous versus induced mouse lung tumors and in Hras-1 mutation incidence and spectrum for spontaneous versus induced mouse liver tumors. The major gene changes reported for human lung and liver tumors were in KRAS2 (lung only) and TP53. The KRAS2 mutation incidence was similar for spontaneous and asbestos-induced human lung tumors, while the TP53 mutation incidence differed significantly. Aflatoxin B1, hepatitis B virus, hepatitis C virus, and vinyl chloride all caused TP53 mutations in human liver tumors, but the mutation spectrum for each agent differed. The incidence of KRAS2 mutations in human compared to mouse lung tumors differed significantly, as did the incidence of Hras and p53 gene mutations in human compared to mouse liver tumors. Differences observed in the mutation spectra for agent-induced compared to spontaneous tumors and similarities in spectra for structurally similar agents support the concept that mutation spectra can serve as a "fingerprint" of exposure based on chemical structure.
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PMID:Genetic alterations in cancer knowledge system: analysis of gene mutations in mouse and human liver and lung tumors. 1641 Mar 70

Oxidative stress and certain environmental carcinogens, e.g. vinyl chloride and its metabolite chloroacetaldehyde (CAA), introduce promutagenic exocyclic adducts into DNA, among them 1,N(6)-ethenoadenine (epsilonA), 3,N(4)-ethenocytosine (epsilonC) and N(2),3-ethenoguanine (epsilonG). We studied sequence-specific interaction of the vinyl-chloride metabolite CAA with human p53 gene exons 5-8, using DNA Polymerase Fingerprint Analysis (DPFA), and identified sites of the highest sensitivity. CAA-induced DNA damage was more extensive in p53 regions which revealed secondary structure perturbations, and were localized in regions of mutation hot-spots. These perturbations inhibited DNA synthesis on undamaged template. We also studied the repair kinetics of CAA-induced DNA lesions in E. coli at nucleotide resolution level. A plasmid bearing full length cDNA of human p53 gene was modified in vitro with 360 mM CAA and transformed into E. coli DH5alpha strain, in which the adaptive response system had been induced by MMS treatment before the cells were made competent. Following transformation, plasmids were re-isolated from transformed cultures 35, 40, 50 min and 1-24 h after transformation, and further subjected to LM-PCR, using ANPG, MUG and Fpg glycosylases to identify the sites of DNA damage. In adaptive response-induced E. coli cells the majority of DNA lesions recognized by ANPG glycosylase were removed from plasmid DNA within 35 min, while MUG glycosylase excised base modifications only within 50 min, both in a sequence-dependent manner. In non-adapted cells resolution of plasmid topological forms was perturbed, suggesting inhibition of one or more bacterial topoisomerases by unrepaired epsilon-adducts. We also observed delayed consequences of DNA modification with CAA, manifesting as secondary DNA breaks, which appeared 3 h after transformation of damaged DNA into E. coli, and were repaired after 24 h.
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PMID:Sequence-specific p53 gene damage by chloroacetaldehyde and its repair kinetics in Escherichia coli. 1658 87

Numerous genetic alterations are accumulated during the process of hepatocarcinogenesis. These genetic alterations can be divided into two groups. The first set of genetic alterations is specific of hepatocellular tumor risk factors. It includes integration of hepatitis B virus (HBV) DNA, R249S TP53 (tumor protein p53) mutation in aflatoxin B1-exposed patients, KRAS mutations related to vinyl chloride exposure, hepatocyte nuclear factor 1alpha (HNF1alpha) mutations associated to hepatocellular adenomas and adenomatosis polyposis coli (APC) germline mutations predisposing to hepatoblastomas. The second set of genetic alterations are etiological nonspecific, it includes recurrent gains and losses of chromosomes, alteration of TP53 gene, activation of WNT/beta-catenin pathway through CTNNB1/beta-catenin and AXIN (axis inhibition protein) mutations, inactivation of retinoblastoma and IGF2R (insulin-like growth factor 2 receptor) pathways through inactivation of RB1 (retinoblastoma 1), P16 and IGF2R. Comprehensive analyses of these genetic alterations have defined two pathways of hepatocarcinogenesis according to the presence or the absence of chromosomal instability. Hepatitis B virus and poorly differentiated tumors are related to chromosome instable tumors associated with frequent TP53 mutations, whereas non-HBV and well-differentiated tumors are related to chromosomal stable samples that are frequently beta-catenin activated. These classifications have clinical relevance as genetic alterations may also be related to prognosis.
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PMID:Genetics of hepatocellular tumors. 1679 19

HCV-associated hepatocellular carcinoma (HCC) is a common neoplasm in Egypt where genotype-4 is prevalent. In the present study the incidence and pattern of p53 mutations was assessed in relation to HCV-genotype- 4 in Egyptian HCC patients. We investigated 25 HCV positive HCCs for p53 mutations/overexpression in relation to HCV-NS3 by immunohistochemistry, SSCP and sequencing. Genotyping was done using LiPA-II and TRUGENE 5' NC' sequencing kit. Results were correlated to standard clinicopathologic prognostic factors for HCC. Thirteen cases showed p53 overexpression, and 10 showed p53 mutation (13 mutations) by sequencing (72% concordance). The highest mutation rate was in exons 6 and 7 (30%) followed by exons 5 and 8 (20%). Mutations included 3 transitions, 5 transversions, 3 deletions, and 2 insertions. All exon 7 mutations were at codon 249 specific for AFB1 (AGG-->AGT, Arg-->Ser) and codon 248 specific for vinyl chloride contamination (CGG-->TGG, Arg-->Trp). Other mutations reported are novel. Immunostaining for HCV NS3 was detected in 19 cases independent of p53 mutation. p53 aberrations were significantly associated with poor prognostic factors for HCC. However, no specific pattern for p53 mutations was observed in HCV genotype 4-associated HCC and no significant relation between p53 mutations, HCV-NS3 expressions or any HCV sub-genotype-4 sequence.
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PMID:p53 mutation in HCV-genotype-4 associated hepatocellular carcinoma in Egyptian patients. 1723 48

This study explores the relationship between genetic polymorphisms of p53, p21, and CCND1, and the susceptibility of chromosomal damage induced by vinyl chloride monomer (CH(2)=CHCl, VCM). Besides gene polymorphisms, we detected the mRNA expression of p53, p21, and CCND1 in VCM-exposed workers and in a control group. One hundred and eighty-three workers occupationally exposed to VCM were investigated. Chromosome damage in peripheral lymphocyte was measured by cytokinesis-block micronucleus assay. The PCR-restriction fragment length polymorphism technique was applied to detect polymorphisms of p53, p21 (exon 2 and exon 3), and CCND1 genes (exon 4). The quantity of gene mRNA expression was detected by real-time PCR (SYBR Green I). Taking into account the effects of genetic polymorphisms, as well as demographic and habitual factors, Poisson regression analysis showed that the risk of chromosomal damage induced by VCM for individuals carrying the p53 intron 6 heterozygous and mutant homozygous genotype was 1.23 times larger (90% confidence interval, 1.01-1.51 P=0.0814), compared with those carrying wild-type homozygous genotypes. The p53 exon 4, intron 3, and intron 6 haplotype pairs of MMM/WWW (M, mutation allele; W, wild allele), and MWM/WWW were associated with increased frequencies of micronuclei. The p53 mRNA expression of VCM-exposed workers was significantly lower than that of nonexposed workers, but p21 mRNA expression in VCM-exposed workers was significantly higher than that of nonexposed workers. Our findings suggest that the p53 intron 6 polymorphism is one of the factors that potentially influence the frequency of micronuclei induced by VCM.
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PMID:Genetic polymorphisms, messenger RNA expression of p53, p21, and CCND1, and possible links with chromosomal aberrations in Chinese vinyl chloride-exposed workers. 1884 98

This study was aimed to elucidate the novel structure of HY251 isolated from the roots of Aralia continentalis and to evaluate its detailed inhibition mechanisms on cell cycle progression in HeLa cells. The structure of HY251 was elucidated based on the interpretation of the NMR spectra, as 3-propyl-2-vinyl-1,2,3,3a,3b,6,7,7a,8,8a-decahydrocyclopenta[a]indene-3,3a,7a,8a-tetraol. The flow cytometric analysis revealed an appreciable G(1) phase arrest in HeLa cells treated with 100 microM of HY251. This HY251-induced G(1) phase arrest is associated with decreased expression of cyclin D3 and up-regulation of p21(CIP1) and p27(KIP1), via p53 phosphorylation at Ser-15 by transcriptional up-regulation of ATM, which resulted in increased hypophosphorylated pRb in HeLa cells.
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PMID:HY251, a novel cell cycle inhibitor isolated from Aralia continentalis, induces G1 phase arrest via p53-dependent pathway in HeLa cells. 1909 50

It is well known that biomaterials play an important role in the regulation of adhesion and growth of a variety of cultured cell types. However, whether biomaterials are associated with the senescence of cultured cells is not known. The present work shows that the decrease of the hydrophobic property of poly (ethylene-co-vinyl alcohol) (EVAL) from 44 mole% to 27 mole% ethylene could induce characteristic senescence-associated phenotypic changes such as larger cell shape, re-organized actin cytoskeleton, lower proliferation capacity, higher levels of senescence-associated beta-galactosidase (SA beta-gal) activity, and upregulation of the cell-cycle inhibitor p53 and its transcriptional target p21 in the cultured human diploid fibroblasts (HDFs). Furthermore, it was found that the cultured cells recovered their ability to grow when the substrate was reused every passage. It seemed that the extracellular matrix (ECM) proteins adsorbed onto the EVAL surface might have a protective role in the cellular aging process. Therefore, whether a biomaterial strongly influences cellular aging process must be considered in the selection of a biomaterial for the biomedical application.
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PMID:The effect of poly (ethylene-co-vinyl alcohol) on senescence-associated alterations of human dermal fibroblasts. 1995 40


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