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)

A close association of smoking-associated lung cancer incidence with the Msp 1 and 1le-Val polymorphisms of CYP1A1 gene was found in a Japanese population in terms of genotype frequency comparison and cigarette dose response. A synergistic increase in susceptibility to lung cancer was observed when the susceptible genotypes of CYP1A1 were combined with a deficient GSTM1 genotype. Individual difference in expression levels of Ahr and Arnt mRNAs was observed, and the expression levels of CYP1A1 appeared to associate with those of transcriptional factors. The Ahr protein has two different structures, ascribed to one amino acid replacement at codon 554 of Arg by Lys. However, this germ line polymorphism did not show a significant association with AHH inducibility nor lung cancer incidence. The p53 gene alterations in lung cancer tissues were more frequently observed among the patients with a susceptible allele of CYP1A1 gene.
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PMID:Genetic polymorphisms of drug-metabolizing enzymes and lung cancer susceptibility. 758 93

We describe studies to determine if susceptibility to pituitary tumours is associated with the putatively high risk GSTM1 null and CYP2D6 EM genotypes. Frequency distributions of these genotypes were similar in cases and controls though the frequency of CYP2D6 PM and GSTM1 B tended to be lower (P = 0.072 and P = 0.095 respectively) in the tumour group. Immunopositivity for p53 was found in 18/97 tumours. In these samples GSTM1 null (39%) and CYP2D6 EM (56%) frequencies were not different to those in controls. The frequencies of CYP2D6 PM and GSTM1 B in the p53 immunonegative tumours tended to be lower (P = 0.055 and P = 0.1185 respectively) than in controls. Mutations in gsp and ras were studied using the polymerase chain reaction and allele specific oligonucleotide analysis. Eight of 19 somatotrophinomas demonstrated mutations in gsp; frequencies of GSTM1 null and CYP02D6 EM were similar to controls. No ras mutations were identified in 55-tumour studies. The data indicate the GSTM1 null and CYP2D6 EM genotypes are not associated with altered expression of p53 or, mutation of gsp and ras in these adenomas and, suggest the CYP2D6 PM genotype is associated with a reduced risk of pituitary adenomas and, that GSTM1*B confers greater protection than GSTM1*A.
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PMID:GSTM1 and CYP2D6 genotype frequencies in patients with pituitary tumours: effects on P53, ras and gsp. 761

We reported an association of smoking-induced lung cancer susceptibility with the human cytochrome P450 1A1 (CYP1A1) polymorphisms in our previous studies. To investigate a relationship between genetically determined individual predispositions and mutations of target genes in the early stage of lung carcinogenesis, we examined p53 mutations in relation to germ line polymorphisms of the CYP1A1 and GSTM1 genes, using surgical specimens of 148 non-small cell lung cancer patients who were smokers. The frequency of p53 mutations among heavy smokers was higher than in patients who had never smoked [P < 0.01; odds ratio (OR), 3.74; 95% confidence interval (CI), 1.46-9.56]. By single-strand conformational polymorphism, aberrant migration bands of p53 gene fragments were detected in 56 cases (38%). Smokers with susceptible rare homozygous alleles of either the MspI or Ile-Val polymorphism of the CYP1A1 gene have a 4.5-fold (P < 0.005; OR, 4.48; 95% CI, 1.64-12.26) or 5.5-fold (P < 0.01; OR, 5.52; 95% CI, 1.55-19.64) higher risk of having a mutation of the p53 gene than those with nonsusceptible predominant homozygous alleles of the gene. Non-small cell lung cancer patients with a susceptible CYP1A1 genotype were at remarkably high risk of having a mutation of the p53 gene when the genotype was combined with a deficient genotype, GSTM1(-). However, there was no difference between the types of p53 mutation and genotypes of the drug-metabolizing enzymes. These results showed that CYP1A1 germ line polymorphisms, which were associated with the genetic predisposition for lung cancer, were related to cigarette smoking-associated p53 mutations.
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PMID:Association of CYP1A1 germ line polymorphisms with mutations of the p53 gene in lung cancer. 854 78

The importance of polymorphism in the glutathione S-transferase GSTM1, GSTT1 and, cytochrome P450, CYP2D6 loci in the pathogenesis of epithelial ovarian cancer has been assessed in two studies; firstly, a case-control study designed to determine the influence of these genes on susceptibility to this cancer, and secondly, the putative role of these genes in the protection of host cell DNA has been studied by comparing p53 expression in patients with different GSTM1, GSTT1 and CYP2D6 genotypes. The frequencies of GSTM1, GSTT1 and CYP2D6 genotypes in 84 cases and 325 controls were not different. Immunohistochemistry was used to detect p53 expression in 63 of these tumours. Expression was found in 23 tumours. Of the patients demonstrating immunopositivity, 20 (87%) were GSTM1 null. The frequency distributions of GSTM1 genotypes in p53-positive and -negative samples were significantly different (P = 0.002) and those for GSTT1 genotypes approached significance (exact P = 0.057). The proportion of patients with both GSTM1 null and GSTT1 null was also significantly greater in the immunopositive (4/22) than in the immunonegative group (1/40) (P = 0.0493). Single-strand conformational polymorphism (SSCP) analysis was used to detect mutations in the 23 tumour samples demonstrating p53 positivity. A shift in electrophoretic mobility of amplified fragments was found in 11 patients (exons 5, 6, 7 and 8) and these exons were sequenced. In eight samples a mutation was found. No SCCP variants were identified in the other 12 immunopositive patients. Sequencing of exons 4-9 of p53 from these tumours resulted in the detection of mutations in two patients (exons 5 and 7). Thus, in 23 patients who demonstrated immunopositivity, p53 mutations were found in nine patients with GSTM1 null (90.0%). In the 13 patients in whom no mutations were identified, 11 were GSTM1 null (84.6%). The data show that overexpression of p53 is associated with the GSTM1 null genotype. We propose the data are compatible with the view that GSTM1 and GSTT1 are critical in the detoxification of the products of oxidative stress produced during the repair of the ovarian epithelium. Thus, failure to detoxify products of this stress may result in damage to various genes in the host cell, including to p53, resulting in persistent expression of mutant protein. In other patients, oxidative stress effects damage to various genes, but not including p53, resulting in overexpression of wild-type p53.
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PMID:Epithelial ovarian cancer: influence of polymorphism at the glutathione S-transferase GSTM1 and GSTT1 loci on p53 expression. 895 89

Occurrence or specific types of mutations found in oncogenes or tumor suppressor genes may partially be determined by activities of toxifying or detoxifying enzymes, such as glutathione S-transferases (GST) M1 and T1, arylamine N-acetyltransferase (NAT2), microsomal epoxide hydrolase, and the cytochrome P-450 enzymes 2D6, 1A1, 2A6, and 2E1. In an explorative observational study, 69 bladder cancer patients were analysed for acquired mutations in the p53 tumor suppressor gene. The same patients were studied for the polymorphic traits of xenobiotic metabolism given above which were characterized from blood cell DNA by molecular methods. In 20 patients, single point mutations in p53 were detected whereas five patients carried two mutations; thus in total 25 mutations were detected. Twelve of these were G:C-->A:T transitions, six were A:T-->G:C transitions and seven were transversions (three G:C-->T:A, two A:T-->T:A, one G:C-->C:G, and one A:T-->C:G). There was no correlation between the types of p53 mutations and lifetime smoking or occupational history. In correlation with xenobiotic metabolism, 86% of the seven transversion mutations were found in homozygously deficient individuals for GSTM1 compared to only 44% of GSTM1 deficiency in the carriers of the 18 transition mutations of p53 (p = 0.06). A similar trend was seen for NAT2: six of the seven carriers of transversion mutations had two slow NAT2 alleles. No apparent associations were seen for the other polymorphic traits which were studied. In conclusion, low or deficient activities of two conjugating enzymes of foreign compound metabolism, GSTM1 and NAT2, may influence types of acquired mutations in p53 in bladder cancer.
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PMID:Polymorphic enzymes of xenobiotic metabolism as modulators of acquired P53 mutations in bladder cancer. 901 3

Several polymorphic genes have been reported to be possibly involved in modifying lung cancer risk in smokers. The gene GSTM1 is frequently deleted in human populations, and the null genotype has been reported to be a risk factor for developing lung carcinoma. A germline polymorphism of p53 with a single-base change at codon 72 that causes an amino acid replacement of arginine (Arg; CGC) by proline (PRO; CCC) has also been reported to be associated with cancer susceptibility in a Japanese population. Both polymorphisms were genotyped by PCR in a northwestern Mediterranean healthy population (n = 147) and in a group of lung cancer patients (n = 139). The results showed that the frequency of the GSTM1 null genotype was higher in the lung cancer patients compared to the controls [odds ratio (OR), 1.57; 95% confidence interval (CI), 0.99-2.51]. The histological subtypes most clearly modified were small cell carcinoma (OR, 1.89; CI, 0.97-3.65) and adenocarcinoma (OR, 1.93; CI, 0.90-4.14). The null GSTM1 genotype was more frequent among those cancer patients who were medium/ light smokers (< or = 50 pack-years) and in those who showed an onset of the disease at a more advanced age. The study of the p53 polymorphism in the healthy population showed allele frequencies of 0.79 (Arg) and 0.21 (Pro). The frequencies found in the lung cancer patients were statistically similar. Both polymorphisms were studied together, and the relative risk of the combination null GSTM1 and Pro/Pro or Arg/Pro genotypes was calculated taking the combination of GTSM1 + together with Arq/Arg as a baseline. The OR found (1.97; CI, 1.03-3.73) suggests that the Pro allele of the p53 germline polymorphism may slightly increase the risk fo the GSTM1 null genotype among smokers.
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PMID:Glutathione-S-Transferase M1 and codon 72 p53 polymorphisms in a northwestern Mediterranean population and their relation to lung cancer susceptibility. 916 98

The A-G polymorphism at codon 104 in the glutathione S-transferase P1 (GSTP1) gene was examined in 138 male lung cancer patients and 297 healthy controls. The patients had significantly higher frequency of the GG genotype (15.9%) and a lower frequency of AA (38.4%) than the controls (9.1% and 51.5%, respectively). The level of hydrophobic DNA-adducts were determined in lung tissue from 70 current smokers. Patients with the GG genotype had a significantly higher adduct level than patients with AA (15.5 +/- 10.2 vs 7.9 +/- 5.1 per 10(8) nucleotides, P = 0.006). We also analyzed the deletion polymorphism in the GSTM1 gene in 135 male patients and 342 controls. The patients were stratified according to histology, smoking dose, age, adduct level and mutational types found in the tumors (Ki-ras and p53 genes). The results consistently indicated that the GSTM1 null genotype was associated with a slightly increased lung cancer risk. When the combined GST M1 and P1 genotypes were examined, patients with the combination null and AG or GG had significantly higher adduct levels than all other genotype combinations (P = 0.011). The distribution of combined genotypes was also significantly different in cases and controls, mainly due to increased frequency of the combination GSTM1 null and GSTP1 AG or GG among patients.
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PMID:Genotypes of glutathione transferase M1 and P1 and their significance for lung DNA adduct levels and cancer risk. 923 Feb 69

To investigate mechanisms causing p53 mutations in lung cancer cases, relations between p53 gene mutations and aetiological factors such as smoking history or family history of cancers cases. The contribution of genotypes related to carcinogen metabolism (CYP1A1 and GSTM1) was also analysed. p53 mutations were observed in 13 cases (37.5%). Seven (53.8%) of the 13 patients with p53 mutation compared with five (22.7%) of 22 patients without had a family history of cancer. However, there was no significant relation between p53 mutation or family history of cancer and CYP1A1 or GSTM1 genotypes. In conclusion, p53 mutation might be associated with the inherited characteristics that result in familial aggregation of lung cancer; however, this association was not explained by genotypes of enzymes related to carcinogen metabolisms.
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PMID:p53 gene mutations, and CYP1A1 and GSTM1 genotypes in pulmonary squamous cell carcinomas. 923 Nov 61

DNA covalently bound to an uncharged nylon membrane was used for consecutive amplifications of several different genes by PCR. Successful PCR amplifications were obtained for membrane-bound genomic and plasmid DNA. Membrane-bound genomic DNA templates were re-used at least 15 times for PCR with specific amplification of the desired gene each time. PCR amplifications of specific sequences of p53, p16, CYP1A1, CYP2D6, GSTM1 and GSTM3 were performed independently on the same strips of uncharged nylon membrane containing genomic DNA. PCR products were subjected to restriction fragment length polymorphism analysis, single-strand conformational polymorphism analysis and/or dideoxy sequencing to confirm PCR-amplified gene sequences. We found that PCR fragments obtained by amplification from bound genomic DNA as template were identical in sequence to those of PCR products obtained from free genomic DNA in solution. PCR was performed using as little as 5 ng genomic or 4 fg plasmid DNA bound to membrane. These results suggest that DNA covalently bound to membrane can be re-used for sample-specific PCR amplifications, providing a potentially unlimited source of DNA for PCR.
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PMID:Re-usable DNA template for the polymerase chain reaction. 925 16

Epidemiologic studies have suggested that smokers of air-cured tobacco (rich in arylamines) are at higher risk of bladder cancer than smokers of flue-cured tobacco. The risk has been shown to be modulated by the N-acetyltransferase genotype. We analyzed the biopsies of 45 patients with bladder cancer. p53 mutations were sought by direct sequencing, and 4-aminobiphenyl-DNA adducts were measured by negative ion gas chromatography-mass spectrometry. 4-Aminobiphenyl-DNA adducts were higher in smokers of air-cured tobacco and in current smokers, but no relationship with the number of cigarettes smoked was found. Adducts were higher in more advanced histologic grades of tumors. No pattern was evident for p53 mutations. Seven of 9 mutations occurred in grade 3 tumors. No association was found between 4-ABP adducts and GSTM1 or NAT2 genetic polymorphisms.
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PMID:4-Aminobiphenyl-DNA adducts and p53 mutations in bladder cancer. 946 49


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