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)

The candidate-gene approach in association studies of polygenic diseases has often yielded conflicting results. In this hospital-based case-control study with 696 white patients newly diagnosed with bladder cancer and 629 unaffected white controls, we applied a multigenic approach to examine the associations with bladder cancer risk of a comprehensive panel of 44 selected polymorphisms in two pathways, DNA repair and cell-cycle control, and to evaluate higher-order gene-gene interactions, using classification and regression tree (CART) analysis. Individually, only XPD Asp312Asn, RAG1 Lys820Arg, and a p53 intronic SNP exhibited statistically significant main effects. However, we found a significant gene-dosage effect for increasing numbers of potential high-risk alleles in DNA-repair and cell-cycle pathways separately and combined. For the nucleotide-excision repair pathway, compared with the referent group (fewer than four adverse alleles), individuals with four (odds ratio [OR] = 1.52, 95% CI 1.05-2.20), five to six (OR = 1.81, 95% CI 1.31-2.50), and seven or more adverse alleles (OR = 2.50, 95% CI 1.69-3.70) had increasingly elevated risks of bladder cancer (P for trend <.001). Each additional adverse allele was associated with a 1.21-fold increase in risk (95% CI 1.12-1.29). For the combined analysis of DNA-repair and cell-cycle SNPs, compared with the referent group (<13 adverse alleles), the ORs for individuals with 13-15, 16-17, and >or=18 adverse alleles were 1.22 (95% CI 0.84-1.76), 1.57 (95% CI 1.05-2.35), and 1.77 (95% CI 1.19-2.63), respectively (P for trend = .002). Each additional high-risk allele was associated with a 1.07-fold significant increase in risk. In addition, we found that smoking had a significant multiplicative interaction with SNPs in the combined DNA-repair and cell-cycle-control pathways (P<.01). All genetic effects were evident only in "ever smokers" (persons who had smoked >or=100 cigarettes) and not in "never smokers." A cross-validation statistical method developed in this study confirmed the above observations. CART analysis revealed potential higher-order gene-gene and gene-smoking interactions and categorized a few higher-risk subgroups for bladder cancer. Moreover, subgroups identified with higher cancer risk also exhibited higher levels of induced genetic damage than did subgroups with lower risk. There was a significant trend of higher numbers of bleomycin- and benzo[a]pyrene diol-epoxide (BPDE)-induced chromatid breaks (by mutagen-sensitivity assay) and DNA damage (by comet assay) for individuals in higher-risk subgroups among cases of bladder cancer in smokers. The P for the trend was .0348 for bleomycin-induced chromosome breaks, .0036 for BPDE-induced chromosome breaks, and .0397 for BPDE-induced DNA damage, indicating that these higher-order gene-gene and gene-smoking interactions included SNPs that modulated repair and resulted in diminished DNA-repair capacity. Thus, genotype/phenotype analyses support findings from CART analyses. This is the first comprehensive study to use a multigenic analysis for bladder cancer, and the data suggest that individuals with a higher number of genetic variations in DNA-repair and cell-cycle-control genes are at an increased risk for bladder cancer, confirming the importance of taking a multigenic pathway-based approach to risk assessment.
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PMID:Bladder cancer predisposition: a multigenic approach to DNA-repair and cell-cycle-control genes. 1646 22

We investigated if the presence of single nucleotide polymorphisms (SNPs) in the XRCC1, XRCC3, and XPD genes were associated with the type and frequency of p53 mutations in bladder cancer. Using a hospital-based case-control study we have previously reported risks for the XRCC1 codon 194, XRCC1 codon 399, XRCC3 codon 241, and XPD codon 751 SNPs 1-3. We have also previously reported mutation data for 149 cases from this study who were screened for mutations in exons 4 through 9 of the p53 gene 4. Here we investigate possible associations between the DNA repair SNPs mentioned above and the presence of p53 mutations by comparing the frequency of each genotype between p53 mutation positive and negative cases. We also considered different classes of p53 mutations, including any mutation (nonsense, missense or silent), transversions and transitions and estimated odds ratios (ORs) and 95% confidence intervals (CI) for these associations. Cases with the XRCC1 codon 399 Gln/Gln genotype were positively associated with the presence of p53 transversions (OR = 4.8; 94% CI = 0.8-30). Cases with the XPD codon 751 Gln/Gln genotype were positively associated with the presence of p53 transitions (OR = 2.8; 95% CI = 0.8-9.3), in particular G:C-A:T transitions (OR = 3.7; 95% CI = 1.1-13). Our data provide some limited support for the hypothesis that mutations in the p53 gene in bladder cancer may differ according to the presence or absence of certain DNA repair gene variants.
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PMID:DNA repair gene polymorphisms and probability of p53 mutation in bladder cancer. 1665 73

The etiology of lung cancer in population with little or no tobacco exposure is not well understood. Individual genetic susceptibility factors have been suggested to contribute to lung cancer risk in this population. Mutations in the p53 tumor suppressor gene are implicated in the development of lung cancer as they are frequently found in lung tumors from both smokers and never-smokers. In order to determine whether genetic polymorphisms affecting DNA repair capacity modulate p53 mutations in lung tumors from never-smokers, we compared p53 mutations with genotypes of XPD 312, XPD 751, and XRCC1 399 in lung tumors from 43 lifetime never-smokers. p53 mutations were identified in 10 (23%) cases and consisted mostly of G/C to A/T transitions. No statistically significant association was found between p53 mutations and genotypes of XPD 312 or XPD 751. However, patients with the XRCC1 399 Gln allele, that results in a lower base excision repair capacity, were more likely to have p53 mutations, compared with patients the wild-type Arg allele (P = 0.03). In addition, the p53 mutation frequency increased with an increasing number of combined genotypes associated with a lower DNA repair capacity of XPD 312, XPD 751, and XRCC1 399 (P = 0.02). These results suggest that individuals who never smoked and had XRCC1 399 Gln allele may be at a greater risk of p53 mutations, especially if combined with the genotypes of XPD 312 and XPD 751 that may result in a lower DNA repair capacity.
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PMID:Polymorphisms in DNA repair genes XPD and XRCC1 and p53 mutations in lung carcinomas of never-smokers. 1686 71

Immunosuppressed renal transplant recipients (RTRs) are predisposed to non-melanoma skin cancers (NMSCs), predominantly squamous cell carcinomas (SCCs). We have analyzed skin lesions from RTRs with aggressive tumors for p53 gene modifications, the presence of Human Papillomas Virus (HPV) DNA in relation to the p53 codon 72 genotype and polymorphisms of the XPD repair gene. We detected 24 p53 mutations in 15/25 (60%) NMSCs, 1 deletion and 23 base substitutions, the majority (78%) being UV-specific C to T transitions at bipyrimidine sites. Importantly, 35% (6/17) are tandem mutations, including 4 UV signature CC to TT transitions possibly linked to modulated DNA repair caused by the immunosuppressive drug cyclosporin A (CsA). We found 8 p53 mutations in 7/17 (41%) precancerous actinic keratosis (AK), suggesting that p53 mutations are early events in RTR skin carcinogenesis. Immunohistochemical analysis shows a good correlation between p53 accumulation and mutations. HPV DNA was detected in 78% of skin lesions (60% Basal Cell Carcinomas, 82%AK and 79% SCCs). Thus, immunosuppression has increased the risk of infections by HPVs, predominantly epidermodysplasia verruciformis, speculated to play a role in skin cancer development. No association is found between HPV status and p53 mutation. Moreover, p53 codon 72 or frequencies of three XPD genotypes of RTRs are comparable with control populations. The p53 mutation spectrum, presenting a high level of CC to TT mutations, shows that the UV component of sunlight is the major risk factor and modulated DNA repair by immunosuppressive drug treatment may be significant in the skin carcinogenesis of RTRs.
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PMID:Analysis of skin cancer risk factors in immunosuppressed renal transplant patients shows high levels of UV-specific tandem CC to TT mutations of the p53 gene. 1706 98

Eukaryotic cells respond to a variety of DNA insults by triggering a common signal transduction cascade, known as checkpoint response, which temporarily halts cell-cycle progression. Although the main players involved in the cascade have been identified, there is still uncertainty about the nature of the structures that activate these surveillance mechanisms. To understand the role of nucleotide excision repair (NER) in checkpoint activation, we analyzed the UV-induced phosphorylation of the key checkpoint proteins Chk1 and p53, in primary fibroblasts from patients with xeroderma pigmentosum (XP), Cockayne syndrome (CS), trichothiodystrophy (TTD), or UV light-sensitive syndrome. These disorders are due to defects in transcription-coupled NER (TC-NER) and/or global genome NER (GG-NER), the NER subpathways repairing the transcribed strand of active genes or the rest of the genome, respectively. We show here that in G0/G1 and G2/M phases of the cell cycle, triggering of the DNA damage cascade requires recognition and processing of the lesions by the GG-NER. Loss of TC-NER does not affect checkpoint activation. Mutations in XPD, XPB, and in TTDA, encoding subunits of the TFIIH complex, involved in both transcription and NER, impair checkpoint triggering. The only exception is represented by mutations in XPD, resulting in combined features of XP and CS (XP/CS) that lead to activation of the checkpoint cascade after UV radiation. Inhibition of RNA polymerase II transcription significantly reduces the phosphorylation of key checkpoint factors in XP/CS fibroblasts on exposure to UV damage.
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PMID:DNA nucleotide excision repair-dependent signaling to checkpoint activation. 1708 60

Drug selection, the key for chemotherapy, is one of the most difficult decision-making in clinic for the treatment of malignant tumors. How to choose is undetermined. Here a new strategy--predictive molecule-targeted chemotherapy (PMTC)--is put forward to choose relatively sensitive chemotherapeutic drugs and to avoid relatively resistant traditional drugs according to the expression of predictive molecules in individual tumor tissue. For example, paclitaxel is regarded as a relatively sensitive drug and may be chosen for the tumors with high expression of p53, while it is predicted as relatively resistant drug and should be avoided for the tumors with high expression of P-glycoprotein (P-gp). Here, we reviewed the predictive values of a variety of molecules, such as p53, P-gp, topoisomerase-1, topoisomerase-2, MSI, BRCA-1, ERCC1, FANC, hMHL1/2, XPD, Bcl-2, ErbB-2, MGMT, dihydropyridine dehydrogenase (DPD), thymidylate synthetase (TS), deoxycytidine kinase (dCK), Ras, Bax, Cyclin A, tubulin proteins, and so on, for the efficacy of some traditional chemotherapeutic drugs, such as platinum, oxaliplatin, cyclophosphamide, ifosfamide, dacarbazine, methotrexate, 5-flurouracil, gemcitabine, vincristine, vinorelbine, paclitaxel, etoposide, irinotecan, topotecan, and so on.
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PMID:[Routine chemotherapeutic drug treatment effectiveness predictive molecules and chemotherapeutic drug selection]. 1716 91

The capital city of Prague is one of the most polluted localities of the Czech Republic. Therefore, the effect of exposure to carcinogenic polycyclic aromatic hydrocarbons (c-PAHs) adsorbed onto respirable air particles (<2.5mum) on chromosomal aberrations was studied in a group of policemen (males, aged 22-50 years) working in the downtown area of Prague and spending daily >8h outdoors (N=53). Age- and sex-matched healthy volunteers spending >90% daily time indoors were chosen as controls (N=52). Ambient air particles (PM10, PM2.5) and c-PAHs were monitored using versatile air pollution sampler (VAPS), and personal exposure was evaluated using personal samplers during working shift. Chromosomal aberrations were analyzed by conventional cytogenetic analysis and fluorescent in situ hybridization (FISH). Urinary cotinine plasma levels of vitamins A, E and C, folate, total cholesterol, HDL, LDL cholesterols and triglycerides were also analyzed as possible effect modifiers. Genotypes CYP1A1*2A, CYP1A1*2C, GSTM1, GSTP1, GSTT1, EPHX1, NAT2, hOGG1, XRCC1, XPD, p53 BstI, p53 MspI, MTHFR677, and MS2656 were determined by PCR-based RFLP assays. The following levels of air pollution were recorded during the study period (mean from HiVol sampling): PM10 62.6microg/m(3), c-PAHs 24.7ng/m(3), B[a]P 3.50ng/m(3). The conventional cytogenetic analysis did not reveal any differences between the group of policemen exposed to the ambient air pollution and the control group. The cytogenetic analysis by FISH analysis used the whole chromosome painting probes for chromosomes #1 and #4 (Cambio, UK). It detected a significant increase in all studied endpoints in the policemen compared to controls (% AB.C.=0.33+/-0.25 versus 0.24+/-0.18, p<0.05, F(G)/100=1.72+/-1.57 versus 1.25+/-1.11, p<0.05, AB/1000 (aberrations/1000 cells)=5.58+/-4.62 versus 3.90+/-3.06, p<0.05). CYP1A1*2C (Ile/Ile), XPD 23 (Lys/Lys), and XPD 6 (CC) genotypes were associated with an increase of aberrant cells by conventional method. Factors associated with an increased level of translocations by FISH included age, smoking, B[a]P-like DNA adducts (corresponding to the exposure of c-PAHs), folate, polymorphisms of CYP1A1*2C, GSTP1, EPHX1, p53 MspI and MTHFR. Ambient air exposure to c-PAHs significantly increased FISH cytogenetic parameters in nonsmoking policemen. We may conclude that FISH indicates that the city policemen in Prague represent a group of increased genotoxic risk. This is the first study that has reported a relationship between DNA adducts (biomarker of exposure) and chromosomal aberrations by FISH (biomarker of effect).
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PMID:Chromosomal aberrations in environmentally exposed population in relation to metabolic and DNA repair genes polymorphisms. 1741 42

The effect of exposure to organic compounds adsorbed onto respirable air particles (<2.5microm) on DNA adducts in lymphocytes was studied in a group of non-smoking policemen (N=109, aged 35+/-0.9 years) working in the downtown area of Prague and spending >8h daily outdoors. Personal exposure to carcinogenic polycyclic aromatic hydrocarbons (c-PAHs) adsorbed on respirable particles was monitored in each subject for 48h before biological sampling. DNA adducts were analyzed by a (32)P-postlabelling assay, and total DNA adduct levels and B[a]P-like spots were determined. Further biomarkers included cotinine levels in urine to control for exposure to tobacco smoke, plasma levels of vitamins A, E and C and polymorphisms of metabolic genotypes (GSTM1, GSTP1, GSTT1, CYP 1A1-Msp I and Ile/Val, MTHFR, MS), DNA repair genotypes (XRCC1, hOGG1 and XPD exons 6 and 23) and the p53 gene (p53 Msp I and BstU I). All the biomarkers of exposure and effect were analyzed repeatedly during a period of one year at 2-3 month intervals (January, March, June, September 2004) to cover periods with high (winter) and low (summer) levels of air pollution. The highest personal exposure to c-PAHs was found in January (8.1+/-8.8ng/m(3)), while the other three sampling periods exhibited 3-4-fold lower c-PAH exposure. The total DNA adducts were only slightly elevated in January (2.08+/-1.60) compared to March (1.66+/-0.65), June (1.96+/-1.73) and September (1.77+/-1.77). B[a]P-like DNA adducts, however, were significantly higher in January than in the March and June sampling periods (0.26+/-0.14 vs. 0.19+/-0.12 and 0.22+/-0.13, respectively; p<0.0001 and p=0.017) indicating that c-PAH exposure probably plays a crucial role in DNA adduct formation in lymphocytes. No effect of individual metabololic or DNA repair genotypes on DNA adduct levels was observed. However, the combination of two genotypes encoding enzymes metabolizing c-PAHs - CYP 1A1 and GSTM1 - was associated with the levels of total and B[a]P-like DNA adducts under conditions of increased exposure to c-PAHs. Our study suggests that DNA adducts in the lymphocytes of subjects exposed to increased c-PAH levels are an appropriate biomarker of a biologically effective dose, directly indicating whether or not the extent of exposure to these compounds is related to an increased mutagenic and carcinogenic risk.
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PMID:Biomarkers of air pollution exposure--a study of policemen in Prague. 1749 40

The aim of the study is to verify the hypothesis that genetic polymorphisms are associated with the predisposition to all malignancies. Using as a model breast cancers from the homogenous Polish population (West Pomeranian region) after stratification of 977 patients by age at diagnosis (under 51 years and above 50 years) and by tumour pathology (ductal cancers--low and high grade, lobular cancers, ER-positive/negative) we tested this hypothesis. Altogether 20 different groups of breast cancer cases have been analyzed. The results were compared to a group of unaffected controls that were matched by age, sex, ethnicity and geographical location and originated from families without cancers of any site among relatives. Molecular alterations selected for analyses included those which have been previously recognized as being associated with breast cancer predisposition. Statistically significant differences between the breast cancer cases and controls were observed in 19 of the 20 analyzed groups. Genetic changes were present in more than 90% of the breast cancer patients in 18 of 20 groups. The highest proportion of cases with constitutional changes-99.3% (139/140) was observed for lobular cancers. The number and type of genetic marker and/or the level of their association with the specific cancer predisposition was different between groups. Markers associated with majority of groups included: BRCA1, CHEK2, p53, TNRnTT, FGFRnAA, XPD CC/AA and XPD GG. Some markers appeared to be group specific and included polymorphisms in CDKN2A, CYP1B1, M3K nAA, and RS67.
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PMID:Genetic contribution to all cancers: the first demonstration using the model of breast cancers from Poland stratified by age at diagnosis and tumour pathology. 1841 14

The cytosine nucleoside analogue 2'-C-cyano-2'-deoxy-1-beta-d-arabino-pentofuranosylcytosine (CNDAC) causes DNA single-strand breaks after its incorporation into DNA. This investigation sought to determine if DNA excision repair pathways were activated to repair this damage. Neither the base excision repair nor the mismatch repair pathway seemed to be involved. Cells deficient in the CSB protein, which initiates transcription-coupled nucleotide excision repair (NER) pathway (TC-NER), exhibited increased clonogenic sensitivity to CNDAC, whereas cells deficient in XPC, which initiates global genome NER, were slightly resistant relative to wild-type cells. The cells lacking either helicase XPB, which unwinds 5' of the lesion, or endonuclease XPF, which incises 5' to a lesion, exhibited increased clonogenic sensitivity to CNDAC, as did cells lacking the XPF partner protein ERCC1. This sensitization was independent of p53 function. Repletion of XPF restored sensitivity comparable with the wild type. In contrast, cells lacking either XPD, the 3'-helicase, or the 3'-endonuclease XPG were equally as sensitive as wild-type cells. In comparison, cells deficient in XPF were not sensitized to other cytosine nucleoside analogues, troxacitabine and cytarabine. Thus, the single-strand nick caused by CNDAC is recognized and, in part, repaired by the TC-NER pathway. NER proteins that function in the 5' direction relative to the UV-induced lesion also participate in the repair of the CNDAC-induced nick, in contrast to proteins that process on the 3' side of the lesion.
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PMID:Repair of 2'-C-cyano-2'-deoxy-1-beta-D-arabino-pentofuranosylcytosine-induced DNA single-strand breaks by transcription-coupled nucleotide excision repair. 1848 73


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