Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0596263 (carcinogenesis)
 64,820 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This review describes the evolution of research into the genetic basis of how different organisms use the process of excision repair to recognize and remove lesions from their cellular DNA. One particular aspect of excision repair, DNA incision, and how it is controlled at the genetic level in bacteriophage, bacteria, S. cerevisae, D. melanogaster, rodent cells and humans is examined. In phage T4, DNA is incised by a DNA glycosylase-AP endonuclease that is coded for by the denV gene. In E. coli, the products of three genes, uvrA, uvrB and uvrC, are required to form the UVRABC excinuclease that cleaves DNA and releases a fragment 12-13 nucleotides long containing the site of damage. In S. cerevisiae, genes complementing five mutants of the RAD3 epistasis group, rad1, rad2, rad3, rad4 and rad10 have been cloned and analyzed. Rodent cells sensitive to a variety of mutagenic agents and deficient in excision repair are being used in molecular studies to identify and clone human repair genes (e.g. ERCC1) capable of complementing mammalian repair defects. Most studies of the human system, however, have been done with cells isolated from patients suffering from the repair defective, cancer-prone disorder, xeroderma pigmentosum, and these cells are now beginning to be characterized at the molecular level. Studies such as these that provide a greater understanding of the genetic basis of DNA repair should also offer new insights into other cellular processes, including genetic recombination, differentiation, mutagenesis, carcinogenesis and aging.
 ...
PMID:The molecular genetics of the incision step in the DNA excision repair process. 290 Aug 58

The repair of damage induced by the alkylating antitumor drug 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU) was investigated using an in vitro excision repair system. Hamster cell extracts prepared from the parental CHO-9 cell line and the ERCC1 mutant 43-3B were both proficient in the repair of CCNU-induced damage. The in vitro repair of CCNU damage was faster than the repair of UV damage and plasmid substrates were rapidly and efficiently incised after incubation with either CHO-9 or 43-3B extracts. 7-Methylguanine (7-meG) and 3-methyladenine (3-meA) glycosylases were active to a similar extent in the CHO-9 and 43-3B extracts. The data indicate that most damage induced by CCNU is repaired via the ERCC1-independent base excision repair pathway, initiating with removal of chloroethylated and hydroxyethylated bases by N-glycosylases. Yet, the sensitive phenotype of 43-3B cells suggests that the ERCC1 gene product is required for the removal of a small subset of CCNU-induced lesions that are important for drug cytotoxicity.
Carcinogenesis 1995 Sep
PMID:Repair of 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea-induced damage by mammalian cell extracts. 755 89

Previous studies have indicated that excision repair genes, such as ERCC1, or early response genes, such as c-fos, may play a significant role in regulating cellular responses to cisplatin (CDDP) by mediating DNA synthesis and repair pathways. This present study aimed to determine whether altered gene expression mediated CDDP resistance expressed in two human tumour sublines following their in vitro exposure to fractionated X-irradiation, not to the drug itself. These sublines, designated SuSa/DXR10 and SKOV-3/DXR10, established respectively from a testicular teratoma cell line (SuSa) or an ovarian carcinoma cell line (SKOV-3), expressed stable 3.1- and 2-fold levels of CDDP resistance, as judged by clonogenic assay. Both sublines expressed c-fos, c-myc and thymidylate synthase (TS) RNA constitutively, but at comparable levels to their parental counterparts. Whilst the ovarian carcinoma cells inherently expressed markedly higher levels (30- to 50-fold) of the excision repair gene ERCC1 than the teratoma cells, only the teratoma DXR10 subline showed an increased level of expression of ERCC1 mRNA relative to their parental cells. Expression of the ERCC3/XPB gene encoding a repair helicase, however, was similar in all the lines tested. The results suggest that CDDP resistance may be mediated by different mechanisms in these DXR10 sublines from those previously identified in drug-selected CDDP-resistant human ovarian A2780/DDP cells.
Carcinogenesis 1994 Sep
PMID:Gene expression in X-irradiated human tumour cell lines expressing cisplatin resistance and altered DNA repair capacity. 792 2

We assessed the possible role of the human repair genes, ERCC1 and ERCC3, in resistance to cisplatin-induced cytotoxicity. The UV repair-deficient Chinese hamster ovary (CHO) 43:3B [designated ERCC1(-)] cell line and its paired subline 83-J5, which is stably transfected with the human DNA excision repair gene ERCC1 [designated ERCC1(+)], were used in this study. UV repair-deficient CHO 27-1 cells [designated ERCC3(-)] and its paired subline designated 'ERCC3(+)', which is stably transfected with the human DNA excision repair gene ERCC3, were also used. In each pair of cell lines, we assessed cisplatin cytotoxicity, cellular drug accumulation and platinum-DNA adduct repair after 1 h drug exposures. Drug accumulation and DNA repair were assessed by atomic absorption spectrometry with Zeeman background correction. ERCC1(+) cells (IC50 = 4.0 microM) were 5-fold more resistant to cisplatin than ERCC1(-) cells (IC50 = 0.75 microM). ERCC1(+) cells repaired 25% of DNA lesions in cellular DNA within a 6 h time period following an IC50 drug exposure and repaired 48% over 24 h. No DNA repair was observed in ERCC1(-) cells during the same time periods. Both cell lines showed similar patterns of drug accumulation. For ERCC3(-) cells (IC50 = 54 microM) and ERCC3(+) cells (IC50 = 49 microM), the profiles of cisplatin sensitivity and cellular drug accumulation were similar. When treated with 50 microM cisplatin, these cells showed similar patterns of drug accumulation, and were equally efficient at forming and repairing lesions in cellular DNA. These data show that in UV repair-deficient CHO cells, ERCC1 confers resistance to cisplatin and confers the ability to remove platinum from cellular DNA. In contrast, ERCC3 does not influence cisplatin drug sensitivity or adduct repair capability. This suggests that ERCC1 may be a determinant of cisplatin resistance, whereas ERCC3 is probably not.
Carcinogenesis 1993 Oct
PMID:Cisplatin sensitivity/resistance in UV repair-deficient Chinese hamster ovary cells of complementation groups 1 and 3. 822 71

DNA repair enzymes play a pivotal role in the maintenance of chromosome integrity and in the elimination of premutagenic lesions from DNA by patrolling the genome; nuclear import mechanisms are implicated in molecular carcinogenesis. We have attempted to predict cell trafficking and the nuclear importation of proteins involved in DNA repair by sequence analysis aimed at identifying karyophilic clusters (arginines, lysines, histidines) flanked by the helix breakers proline or glycine that could function as nuclear localization signals (NLSs). Most mammalian proteins that participate in DNA repair pathways seem to possess NLS peptides. Repair proteins with multiple nuclear signals are the ERCC6 helicase (eight signals), the XPC protein involved in the repair of the transcribed strand in active genes (eight strong and seven weak signals), and the Rep-3/Duc-1 mismatch repair protein (five strong one weak signal). We propose that it is unlikely to identify mutations on the genes encoding these proteins resulting in cytoplalsmic retention. However, a number of mammalian DNA repair proteins lack NLS clusters; these proteins include ERCC1, ERCC2 (XPD), mouse RAD51, and the HHR23B/p58 and HHR23A subunits of XPC. NLS-less S. cerevisiae proteins include both RAD51 and RAD52 that function in the recombination and in the repair of double-strand breaks as well as the RAD23 and HRR25 molecules. We propose that these proteins depend on their complexation with other proteins in the cytoplasm for their nuclear localization. The hMSH2 human mismatch repair protein linked to the hereditary nonpolyposis colon cancer gene, has a weak nuclear signal containing two histidines.
 ...
PMID:Nuclear import of DNA repair proteins. 913 18

Epidemiological studies have indicated that reduced DNA repair capacity and increased DNA adduct levels are associated with increased risk of lung cancer. Nucleotide excision repair (NER) is the major pathway in humans for repairing DNA adducts induced by smoking-related carcinogens, such as benzo[a]pyrene diol epoxide. We hypothesized that genetically determined baseline expression level of genes involved in NER is associated with risk of lung cancer. In a pilot case-control study, we measured the relative expression levels of five NER genes [ERCC1, XPB/ERCC3, XPG/ERCC5, CSB/ERCC6 and XPC (ERCC, excision repair cross-complementing; CSB, Cockayne's syndrome complementary group B)] in phytohemagglutinin-stimulated peripheral lymphocytes obtained from 75 lung cancer patients and 95 controls using a newly developed multiplex RT-PCR assay. Cases and controls were matched on age, sex, ethnicity and tobacco use. The expression level of the beta-actin gene was used as an internal control for the relative quantitation. We observed a 12.2 and 12.5% decrease in the baseline expression levels of XPG/ERCC5 and CSB/ERCC6, respectively, in cases compared with controls. These differences were statistically significant (P < 0.01) when the median expression level in the controls was used as the cut-off point, the lung cancer patients were significantly more likely than the controls to have reduced expression levels of XPG/ERCC5 [odds ratio (OR), 2.32; 95% confidence interval (CI), 1.22-4.43] and CSB/ERCC6 (OR, 2.49; 95% CI, 1.28-4.84). There was also a dose-response relationship between reduced expression levels and increased lung cancer risk (trend test: P < 0.01). Our results suggest that individuals whose expression levels of XPG/ERCC5 and CSB/ERCC6 are reduced may be at higher risk of lung cancer.
Carcinogenesis 2000 Aug
PMID:Reduced expression levels of nucleotide excision repair genes in lung cancer: a case-control analysis. 1091 Sep 54

Gliomas include several histologically distinct types of tumors whose molecular profiles suggest different etiologies. Because the ERCC1 protein is essential for nucleotide excision repair and influences genomic instability, polymorphisms in ERCC1 may play a role in human tumors. We determined the presence of the A versus C polymorphism at nucleotide 8092 of ERCC1 using a single-strand conformational polymorphism assay and DNA sequencing in adults with glioma and controls from a population-based study. Among 318 alleles from 159 controls, 27% (86) were A and 73% were C. Prevalences of the CC genotype were 51% (81 of 159), 48% (30 of 62), 63% (20 of 32), and 82% (23 of 28) for controls and subjects with glioblastoma multiforme, astrocytoma, and oligoastrocytoma, respectively (Fisher's exact P = 0.009). The age-adjusted odds ratio for genotype CC in all cases versus controls was 1.4 (95% confidence interval, 0.9-2.3), whereas that for subjects with oligoastrocytoma versus controls was 4.6 (95% confidence interval, 1.6-13.2). The median age at diagnosis was 46 years for glioma patients with the CC genotype compared with 54 years for patients with the AA or AC genotype (P = 0.04). This is the first study to report a significant association of a polymorphism in ERCC1 with the risk of brain tumors. This A/C polymorphism, which may affect mRNA stability for ERCC1, also results in an amino acid substitution of lysine to glutamine in a recently described nucleolar protein (ASE-1) and T-cell receptor complex subunit CD3epsilon-associated signal transducer (CAST). This finding, if confirmed in other series, may provide a foundation on which to study novel mechanisms of carcinogenesis in subsets of glioma.
 ...
PMID:Association of an ERCC1 polymorphism with adult-onset glioma. 1095 3

Variation in gene coding sequence represents a significant factor in predisposition to disease, including cancer. Variants of some DNA repair genes (e.g. MLH1, MSH2 and MSH6) are known to predispose to cancer. We identified single nucleotide polymorphisms (SNPs) in five DNA repair genes in 142 healthy individuals using a DNA sequencing protocol optimized for the direct detection of single nucleotide polymorphisms. This approach, called the heterozygote sequencing protocol (HSP), enables moderate-scale population surveys of SNPs. HSP uses fluorescently tagged primers and exploits the large dynamic range and low background of automated fluorescent sequencing. HSP may be used for any sequence that can be amplified by PCR. A total of 12 SNP variants in MGMT, ERCC1, CDK7, CCNH and XRCC4 were identified, 11 at polymorphic frequencies, with an average frequency of 0.22 (95% confidence interval 0.20-0.24). Among the 82 individuals for whom complete SNP profiles were available, no one person carried the GenBank reference sequence for all five genes. The extensive heterogeneity observed in these five genes is intriguing. All variants are in Hardy-Weinberg equilibrium, although the meaning of this equilibrium is unclear. Using this approach, possible associations of sequence variation, and hence of variation in DNA repair, with disease risk can be assessed.
Carcinogenesis 2000 Nov
PMID:Identification of single nucleotide polymorphisms in human DNA repair genes. 1106 57

The contribution of oxidative stress, different types of DNA damage and expression of DNA repair enzymes in colon and liver mutagenesis induced by 2-amino-3-methylimidazo [4,5-f]quinoline (IQ) was investigated in four groups of six Big Blue rats fed diets with 0, 20, 70, and 200 mg IQ/kg for 3 weeks. There were dose-response relationships of DNA adducts ((32)P-postlabeling) and DNA strand breaks (comet assay) in colon and liver tissues, with the highest levels of DNA adducts and strand breaks in the colon. There was dose-dependent induction of mutations in both the colon and the liver, and the same IQ dose produced two-fold more cII mutations in the liver compared with the colon. The IQ-induced mutation spectrum in the colon was not significantly different to that of control rats. The expression of ERCC1 and OGG1 was higher in the colon than liver, and was unaffected by the IQ diet. Investigations of oxidative stress biomarkers produced inconclusive results. Oxidative DNA damage detected by the endonuclease III enzyme and 7-hydro-8-oxo-2'-deoxyguanosine in colon, liver and/or urine was unaltered by IQ. However, there was increased level of gamma-glutamyl semialdehyde in liver proteins, indicating a higher rate of protein oxidation in the liver following IQ administration. In plasma and erythrocytes there were unaltered levels of oxidized protein, malondialdehyde, and antioxidant enzyme activities (superoxide dismutase, glutathione peroxidase, catalase, glutathione reductase) indicating no systemic oxidative stress. However, the level of total vitamin C was increased in plasma, with the largest fraction being in the reduced form. In conclusion, our results indicate that DNA adducts rather than oxidative stress are responsible for the initiation of IQ-induced carcinogenesis of the liver and colon. A lower frequency of mutations in the colon than in the liver could be related to higher expression of DNA repair enzymes in the former.
Carcinogenesis 2002 Aug
PMID:Mutagenicity of 2-amino-3-methylimidazo[4,5-f]quinoline in colon and liver of Big Blue rats: role of DNA adducts, strand breaks, DNA repair and oxidative stress. 1215 58

The mRNA levels of the nucleotide excision DNA repair gene ERCC1 and the base excision DNA repair gene OGG1 were quantified in 43 healthy volunteers in a dietary intervention trial as markers for the DNA repair capacity. Nine samples were collected from each subject over a period of 52 days. Sampling took place from January to May. The mRNA levels of OGG1 and ERCC1 correlated closely (r = 0.86, P << 0.0001) after normalization to either 18S ribosomal RNA or to beta-actin mRNA. The levels of OGG1 and ERCC1 mRNA were relatively constant within an individual with intra-individual correlation (R(2) = 0.45-0.46) in a General Linear Model. The amounts of ERCC1 and OGG1 relative to 18S RNA were doubled in May compared with January. This coincided with an increase in the monthly influx of sunlight from 18 MJ/m(2) in January to 242 MJ/m(2) in May. The mRNA levels of both ERCC1 and OGG1 were positively correlated to the average daily influx of sunlight in the previous 30 and 5 days (r = 0.49; r = 0.37, respectively, P << 0.001). There were no significant effects of the dietary interventions. The inter-individual variation was 5-10-fold, which is more than the observed 2-3-fold seasonal variation. Thus, despite seasonal variation of the individual mRNA levels, the inter-person variation is still far larger than the intra-person variation, supporting the use as biomarkers.
Carcinogenesis 2002 Sep
PMID:Inter-individual variation, seasonal variation and close correlation of OGG1 and ERCC1 mRNA levels in full blood from healthy volunteers. 1218 94


1 2 3 4 5 6 Next >>