Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Keywords: CANCER ; CELLS ; EXPRESSION ; IN-VIVO ; LUNG-CANCER ; DNA adducts ; RISK ; GENE ; LINES ; ACTIVATION ; DNA ; 3-aminobenzanthrone ; 3-nitrobenzanthrone ; AIR ; CARCINOGENESIS ; CYP1A2 ; CYTO-TOXIC METABOLITES ; DIESEL EXHAUST ; DNA ADDUCT FORMATION ; ENVIRONMENTAL CONTAMINANT 3-NITROBENZANTHRONE ; GENETIC POLYMORPHISMS ; HETEROCYCLIC AMINES ; HETEROLOGOUS EXPRESSION ; HUMAN CYTOSOLIC SULFOTRANSFERASES ; IONS ; metabolic activation ; NAT : SULT ; nitro-PAH ; P-32- postlabeling ; PHENOL SULFOTRANSFERASES ; POSTLABELING ANALYSIS
    Abstract: 3-Nitrobenzanthrone (3-NBA) is a potent mutagen and suspected human carcinogen identified in diesel exhaust and ambient air pollution. 3-Aminobenzanthrone (3-ABA), 3- acetylaminobenzanthrone (3-Ac-ABA) and N-acetyl-N-hydroxy-3- aminobenzanthrone (N-Ac-N-OH-ABA) have been identified as 3-NBA metabolites. Recently we found that 3-NBA and its metabolites (3-ABA, 3-Ac-ABA and N-Ac-N-OH-ABA) form the same DNA adducts in vivo in rats. In order to investigate whether human cytochrome P450 (CYP) enzymes (i.e., CYPIA2), human N,O- acetyltransferases (NATs) and sulfotransferases (SULTs) contribute to the metabolic activation of 3-NBA and its metabolites we developed a panel of Chinese hamster V79MZ-hIA2 derived cell lines expressing human CYPIA2 in conjunction with human NATI, NAT2, SULTIAI or SULTIA2, respectively. Cells were treated with 0.01, 0.1 or I muM 3-NBA, or its metabolites (3- ABA, 3-Ac-ABA and N-Ac-N-OH-ABA). Using both enrichment versions of the P-32-postlabeling assay, nuclease P I digestion and butanol extraction, essentially 4 major and 2 minor DNA adducts were detected in the appropriate cell lines with all 4 compounds. The major ones were identical to those detected in rat tissue; the adducts lack an N-acetyl group. Human CYPIA2 was required for the metabolic activation of 3-ABA and 3-Ac-ABA (probably via N-oxidation) and enhanced the activity of 3-NBA (probably via nitroreduction). The lack of acetylated adducts suggests N-deacetylation of 3-Ac-ABA and N-Ac-N-OH-ABA. Thus, N-hydroxy-3-aminobenzanthrone (N-OH-ABA) appears to be a common intermediate for the formation of the electrophilic arylnitrenium ions capable of reacting with DNA. Human NAT I and NAT2 as well as human SULTIAI and SULTIA2 strongly contributed to the high genotoxicity of 3-NBA and its metabolites. Moreover, N,O-acetyltransfer reactions catalyzed by human NATs leading to the corresponding N-acetoxyester may be important in the bioactivation of N-Ac-N-OH-ABA. As human exposure to 3-NBA is likely to occur primarily via the respiratory tract, expression of CYPs, NATs and SULTs in respiratory tissues may contribute significantly and specifically to the metabolic activation of 3-NBA and its metabolites. Consequently, polymorphisms in these genes could be important determinants of lung cancer risk from 3-NBA
    Type of Publication: Journal article published
    PubMed ID: 12740904
    Signatur Availability
    BibTip Others were also interested in ...
  • 2
    Keywords: SPECTRA ; CANCER ; CELLS ; CELL ; human ; DNA adducts ; EXPOSURE ; RISK ; GENE ; TISSUE ; PATIENT ; DNA ; MECHANISM ; CARCINOGENESIS ; DNA ADDUCT FORMATION ; RATS ; tumour ; ASSOCIATION ; ACID ; NUMBER ; MUTATION ; p53 ; MUTATIONS ; ADDUCTS ; INDIVIDUALS ; NEPHROPATHY ; mutagenesis ; CONSUMPTION ; aristolochic acid ; CHINESE HERBS NEPHROPATHY ; DNA-ADDUCTS ; RENAL-FAILURE ; molecular ; FEATURES ; ONCOLOGY ; MOLECULAR-MECHANISM ; RE ; PATTERN ; P53 GENE ; RAS GENE ; ADDUCT FORMATION ; development ; analysis ; DNA ADDUCT ; p53 mutation ; RISK-FACTOR ; SPECTRUM ; PREDICT ; aetiology ; COVALENT DNA ADDUCTION ; HUMAN P53 GENE ; OCHRATOXIN-A
    Abstract: Balkan endemic nephropathy (BEN) is found in certain rural areas of the Balkans and affects at least 25 000 inhabitants. Of the many hypotheses on BEN, the Aristolochia hypothesis has recently gained ground substantiated by the investigations on aristolochic acid nephropathy (AAN). On both clinical and morphological grounds, AAN is very similar to BEN. That exposure to aristolochic acid (AA) of individuals living in endemic areas through consumption of bread made with flour contaminated with seeds of Aristolochia clematitis is responsible for BEN is an old hypothesis, but one which is fully consistent with the unique epidemiologic features of BEN. Here, we propose an approach to investigate AA-induced mutagenesis in BEN that can provide molecular clues to the aetiology of its associated urothelial cancer. The molecular mechanism of AA-induced carcinogenesis demonstrates a strong association between DNA adduct formation, mutation pattern and tumour development. A clear link between urothelial tumours, p53 mutations and AA exposure should emerge as more tumour DNA from BEN patients from different endemic areas becomes available for mutation analysis. We predict that the observed p53 mutation spectrum will be dominated by AT -〉 TA transversion mutations as has already been demonstrated in the human p53 gene of immortalized cells after exposure to AAI and urothelial tumours from BEN patients in Croatia. Moreover, the detection of AA-specific DNA adducts in renal tissue of a number of BEN patients and individuals living in areas endemic for BEN in Croatia provides new evidence that chronic exposure to AA is a risk factor for BEN and its associated cancer
    Type of Publication: Journal article published
    PubMed ID: 17434925
    Signatur Availability
    BibTip Others were also interested in ...
  • 3
    Keywords: CELLS ; IN-VITRO ; CELL ; human ; IN-VIVO ; LUNG ; MODEL ; PATHWAY ; PATHWAYS ; VITRO ; VIVO ; SYSTEM ; liver ; MICE ; TIME ; ACTIVATION ; DNA ; 3-aminobenzanthrone ; 3-nitrobenzanthrone ; AIR ; CARCINOGENESIS ; DIESEL EXHAUST ; DNA ADDUCT FORMATION ; CONTAMINANT 3-NITROBENZANTHRONE ; BINDING ; bone marrow ; BONE-MARROW ; MOUSE ; MUTANT ; TRANSGENIC MICE ; ASSAY ; genetics ; genotoxicity ; DNA-BINDING ; METABOLIC-ACTIVATION ; NUCLEOTIDES ; POLYCYCLIC AROMATIC-HYDROCARBONS ; EPITHELIAL-CELLS ; ADDUCTS ; heredity ; BODIES ; RE ; air pollution ; INCREASE ; ADDUCT FORMATION ; LEVEL ; BONE ; ENGLAND ; PREDICT ; INCREASES ; ENVIRONMENTAL-POLLUTANT 3-NITROBENZANTHRONE ; NOV ; outcome ; MARROW ; NUCLEOTIDE ; CARCINOGEN 3-NITROBENZANTHRONE ; HUMAN METABOLITE ; URBAN AIR-POLLUTION
    Abstract: FE1 lung epithelial cells derived from Muta (TM) Mouse are a new model system to provide in vitro mutagenicity data with the potential to predict the outcome of an in vivo Muta (TM) Mouse test. 3-Nitrobenzanthrone (3-NBA) is a potent mutagen and suspected human carcinogen identified in diesel exhaust and urban air pollution. We investigated the mutagenicity and DNA binding of 3-NBA and its main metabolite 3-aminobenzanthrone (3-ABA) in vitro and in vivo in the Muta (TM) Mouse assay. Mice were treated with 3-NBA or 3-ABA (0, 2 or 5 mg/kg body weight/day) by gavage for 28 days and 28 days later lacZ mutant frequency (MF) was determined in liver, lung and bone marrow. For both compounds, dose-related increases in MF were seen in liver and bone marrow, but not in lung; mutagenic activity was similar to 2-fold lower for 3-ABA than for 3-NBA. With 3-NBA, highest DNA adduct levels (measured by P-32-post-labelling) were found in liver (similar to 230 adducts per 10(8) nucleotides) with levels 20- to 40-fold lower in bone marrow and lung. With 3-ABA, DNA adduct levels were again highest in the liver, but similar to 4-fold lower than for 3-NBA. FE1 cells were exposed to up to 10 mu g/ml 3-NBA or 3-ABA for 6 h with or without exogenous activation (S9) and harvested after 3 days. For 3-NBA, there was a dose-related increase in MF both with and without S9 mix, which was 〉 10 times higher than observed in vivo. At the highest concentration of 3-ABA (10 mu g/ml), we found only around a 2-fold increase in MF relative to controls. DNA adduct formation in FE1 cells was dose-dependent for both compounds, but 10- to 20-fold higher for 3-NBA compared to 3-ABA. Collectively, our data indicate that Muta (TM) Mouse FE1 cells are well suited for cost-effective testing of suspected mutagens with different metabolic activation pathways as a guide for subsequent in vivo Muta (TM) Mouse testing
    Type of Publication: Journal article published
    PubMed ID: 18635558
    Signatur Availability
    BibTip Others were also interested in ...
  • 4
    Keywords: APOPTOSIS ; CANCER ; CANCER CELLS ; CELLS ; EXPRESSION ; CELL ; human ; INHIBITION ; PATHWAY ; PATHWAYS ; GENE ; GENE-EXPRESSION ; GENES ; microarray ; ACCUMULATION ; LINES ; RESPONSES ; DNA ; CARCINOGENESIS ; DNA ADDUCT FORMATION ; cell cycle ; CELL-CYCLE ; CELL-LINES ; ACID ; gene expression ; MUTATION ; CELL-LINE ; MODULATION ; CANCER-CELLS ; MUTATIONS ; PARAMETERS ; ONCOGENE ; EPITHELIAL-CELLS ; ADDUCTS ; DNA-REPLICATION ; REPLICATION ; OUTCOMES ; AD ; NEPHROPATHY ; SUBSTRATE-SPECIFICITY ; INJURY ; TP53 ; aristolochic acid ; BALKAN ENDEMIC NEPHROPATHY ; CHINESE HERBS NEPHROPATHY ; AGENT ; UROTHELIAL CARCINOMA ; RE ; P53 GENE ; DEPENDENCE ; ADDUCT FORMATION ; PHASE ; PROFILES ; signalling ; EXPRESSION PROFILES ; pharmacology ; USA ; OXIDATIVE DNA-DAMAGE ; ENGLAND ; aristolochic acid nephropathy ; PROFILE ; outcome ; response ; biological ; expression profile ; CALPAIN INHIBITION ; RENAL FIBROSIS ; Urothelial cancel
    Abstract: Aristolochic acid (AA) is the Causative agent of urothelial tumours associated with aristolochic acid nephropathy. These tumours contain TP53 mutations and over-express TP53. We compared transcriptional and translational responses of two isogenic HCT116 cell lines, one expressing TP53 (p53-WT) and the other with this gene knocked out (p53-null), to treatment with aristolochic acid I (AAI) (50-100 mu M) lor 6-48 h. Modulation of 118 genes was observed in p53-WT cells ad 123 genes in p53-null cells. Some genes, including INSIG1, EGR1, CAV1, LCN2 arid CCNG1, were differentially expressed in the two cell lines. CDKN1A was selectively Up-regulated in p53-WT cells, leading to accumulation of TP53 and CDKN1A. Apoptotic signalling, measured by caspase-3 and -7 activity, was TP53-dependent. Both cell types accumulated in S phase, suggesting that AAI-DNA adducts interfere with DNA replication, independently of TP53 Status. The oncogene MYC, frequently over expressed ill urothelial turnouts, Was Up-regulated by AAI, whereas FOS was down-regulated. Observed modulation of genes involved in endocytosis, e.g. RAB5A, may be relevant to the known inhibition of receptor-mediated endocytosis, an early sign of AA-mediated proximal tubule injury. AAI-DNA adduct Formation was significantly greater in p53-WT cells than in p53-null cells. Collectively, phenotypic anchoring of the AAI-induced expression profiles to DNA adduct formation, cell-cycle parameters, TP53 expression arid apoptosis identified several genes linked to these biological outcomes, some of which are TP53-dependent. These results strengthen the importance of TP53 in AA-induced cancer, arid indicate that other alterations, e.g. to MYC oncogenic pathways, may also contribute. (C) 2008 Elsevier Inc. All rights reserved
    Type of Publication: Journal article published
    PubMed ID: 18639569
    Signatur Availability
    BibTip Others were also interested in ...
  • 5
    Keywords: CANCER ; CELLS ; EXPRESSION ; INHIBITOR ; IN-VIVO ; INHIBITION ; LUNG-CANCER ; DNA adducts ; SAMPLES ; TIME ; ACTIVATION ; DNA ; 3-nitrobenzanthrone ; AIR ; CARCINOGENESIS ; DIESEL EXHAUST ; DNA ADDUCT FORMATION ; ENVIRONMENTAL CONTAMINANT 3-NITROBENZANTHRONE ; metabolic activation ; AIR-POLLUTION ; INDUCTION ; LIVER-MICROSOMES ; P-450 REDUCTASE ; RAT ; SUDAN-I
    Abstract: Determining the capability of humans to metabolize the suspected carcinogen 3-nitrobenzanthrone (3-NBA) and understanding which human enzymes are involved in its activation are important in the assessment of individual susceptibility to this environmental contaminant found in diesel exhaust and ambient air pollution. We compared the ability of eight human hepatic microsomal samples to catalyze DNA adduct formation by 3-NBA. Using two enrichment procedures of the P-32-postlabeling method, nuclease P1 digestion and butanol extraction, we found that all hepatic microsomes were competent to activate 3-NBA. DNA adduct patterns with multiple adducts, qualitatively similar to those found recently in vivo in rats, were observed. Additionally one major DNA adduct generated by human microsomes was detected. The role of specific cytochromes P450 (P450) and NADPH:P450 reductase in the human hepatic microsomal samples in 3-NBA activation was investigated by correlating the P450- and NADPH:P450 reductase- linked catalytic activities in each microsomal sample with the level of DNA adducts formed by the same microsomes. On the basis of this analysis, most of the hepatic microsomal activation of 3-NBA was attributed to NADPH:P450 reductase. Inhibition of DNA adduct formation in human liver microsomes by a-lipoic acid, an inhibitor of NADPH:P450 reductase, supported this finding. Using the purified rabbit enzyme and recombinant human NADPH:P450 reductase expressed in Chinese hamster V79 cells, we confirmed the participation of this enzyme in the formation of 3-NBA-derived DNA adducts. Moreover, essentially the same DNA adduct pattern found in microsomes was detected in metabolically competent human lymphoblastoid MCL-5 cells. The role of individual human recombinant P450s 1A1, 1A2, 1B1, 2A6, 2B6, 2D6, 2C9, 2E1, and 3A4 and of NADPH:P450 reductase in the metabolic activation of 3-NBA, catalyzing DNA adduct formation, was also examined using microsomes of baculovirus-transfected insect cells containing the recombinant enzymes (Supersomes). DNA adducts were observed in all Supersomes preparations, essentially similar to those found with human hepatic microsomes and in human cells. Of all of the recombinant human P450s, P450 2B6 and -2D6 were the most efficient to activate 3- NBA, followed by P450 1A1 and -1A2. These results demonstrate for the first time the potential of human NADPH:P450 reductase and recombinant P450s to contribute to the metabolic activation of 3-NBA by nitroreduction
    Type of Publication: Journal article published
    PubMed ID: 12782579
    Signatur Availability
    BibTip Others were also interested in ...
  • 6
    Keywords: CELLS ; IN-VITRO ; human ; IN-VIVO ; LUNG ; PATHWAYS ; VIVO ; DNA adducts ; EXPOSURE ; liver ; ENZYMES ; TISSUE ; HEART ; ACTIVATION ; DNA ; kidney ; 3-aminobenzanthrone ; 3-nitrobenzanthrone ; CARCINOGENESIS ; DIESEL EXHAUST ; DNA ADDUCT FORMATION ; metabolic activation ; nitro-PAH ; RAT ; animals ; AROMATIC-AMINES ; BASE ; BIOMARKERS ; BODY-WEIGHT ; colon ; CONTAMINANT 3-NITROBENZANTHRONE ; ENRICHMENT ; HPLC ; P-32-postlabelling ; RATS ; TISSUES ; tumour
    Abstract: Diesel exhaust is known to induce tumours in animals and is suspected of being carcinogenic in humans. Of the compounds found in diesel exhaust, 3-nitrobenzanthrone (3-NBA) is an extremely potent mutagen and suspected human carcinogen forming multiple DNA adducts in vitro. 3-Aminobenzanthrone (3-ABA). 3- acetylaminobenzanthrone (3-Ac-ABA), and N-acetyl-N-hydroxy-3- aminobenzanthrone (N-Ac-N-OH-ABA) were identified as 3-NBA metabolites. In order to gain insight into the pathways of metabolic activation leading to 3-NBA-derived DNA adducts we treated Wistar rats intraperitoneally with 2 mg/kg body weight of 3-NBA, 3-ABA. 3-Ac-ABA, or N-Ac-N-OH-ABA and compared DNA adducts present in different organs, With each compound either four or five DNA adduct spots were detected by TLC in all tissues examined (lung, liver. kidney, heart, pancreas, and colon) using the nuclease P1 or butanol enrichment version of the P-32-postlabelling method, respectively. Using HPLC co- chromatographic analysis we showed that all major 3-NBA-DNA adducts produced in vivo in rats are derived from reductive metabolites bound to purine bases and lack an N-acetyl group. Our results indicate that 3-NBA metabolites (3-ABA, 3-Ac-ABA and AT-Ac-N-OH-ABA) undergo several biotransformations and that N-hydroxy-3-aminobenzanthrone (N-OH-ABA) appears to be the common intermediate in 3-NBA-derived DNA adduct formation. Therefore, 3-NBA-DNA adducts are useful biomarkers for exposure to 3-NBA and its metabolites and may help to identify enzymes involved in their metabolic activation. (C) 2002 Elsevier Science (USA). All rights reserved
    Type of Publication: Journal article published
    PubMed ID: 12480528
    Signatur Availability
    BibTip Others were also interested in ...
  • 7
    Keywords: CANCER ; CELLS ; IN-VITRO ; CELL ; EXPOSURE ; GENE ; SAMPLES ; MICE ; PATIENT ; DNA ; CARCINOGENESIS ; ACID ; DATABASE ; MUTATIONS ; mutagenesis ; P53 MUTATIONS ; immortalization ; INVESTIGATE ; TP53 mutation ; cancer aetiology
    Abstract: The proposal has been put forward that the primary cause of Balkan endemic nephropathy (BEN) is exposure to food crops contaminated with seeds of Aristolochia spp, which contain high levels of aristolochic acids (AA). Recently. tumour DNA samples from patients with BEN were found to harbour principally A to T mutations in the TP53 tumour suppressor gene (Grollman et al., Proc Natl Acad Sci USA 2007;104:12129-34). Using a novel mutation assay in which we can induce and select mutations in human TP53 sequences in vitro by exposure of cultured cells to a mutagen, we found that A to T mutations were elicited by aristolochic acid at sites in TP53 rarely mutated in human cancers in general, but which were observed in the BEN patients. This concordance of specific mutations in patient tumours and aristolochic acid exposed cultures supports the argument that AA has a direct role in the aetiology of BEN-associated cancer. (C) 2008 Wiley-Liss. Inc
    Type of Publication: Journal article published
    PubMed ID: 19030178
    Signatur Availability
    BibTip Others were also interested in ...
  • 8
    Keywords: CELLS ; IN-VITRO ; human ; IN-VIVO ; VITRO ; LUNG-CANCER ; DNA adducts ; liver ; MICE ; ACTIVATION ; DNA ; kidney ; 3-aminobenzanthrone ; 3-nitrobenzanthrone ; CARCINOGENESIS ; DIESEL EXHAUST ; AIR-POLLUTION ; CONTAMINANT 3-NITROBENZANTHRONE ; P-32-postlabelling ; BINDING ; METABOLITES ; BREAST ; DNA-BINDING ; HUMAN ACETYLTRANSFERASES ; METABOLIC-ACTIVATION ; cytochrome P450 ; V79 CELLS ; RE ; air pollution ; MYELOPEROXIDASE ; ENZYME ; CARCINOGENIC ARISTOLOCHIC ACIDS ; SULFOTRANSFERASES ; reductive activation ; in vivo ; PROSTAGLANDIN-H SYNTHASE
    Abstract: 3-Nitrobenzanthrone (3-NBA) is a suspected human carcinogen found in diesel exhaust and ambient air pollution. The main metabolite of 3-NBA, 3-aminobenzanthrone (3-ABA), was detected in the urine of salt mining workers occupationally exposed to diesel emissions. We evaluated the role of hepatic cytochrome P450 (CYP) enzymes in the activation of 3-ABA in vivo by treating hepatic cytochrome P450 oxidoreductase (POR)-null mice and wild-type littermates intraperitoneally with 0.2 and 2 mg/kg body weight of 3-ABA. Hepatic POR-null mice lack POR-mediated CYP enzyme activity in the liver. Using the P-32-postlabelling method, multiple 3-ABA-derived DNA adducts were observed in liver DNA from wild-type mice, qualitatively similar to those formed in incubations using human hepatic microsomes. The adduct pattern was also similar to those formed by the nitroaromatic counterpart 3-NBA and which derive from reductive metabolites of 3-NBA bound to purine bases in DNA. DNA binding by 3-ABA in the livers of the null mice was undetectable at the lower dose and substantially reduced (by up to 80%), relative to wild-type mice, at the higher dose. These data indicate that POR-mediated CYP enzyme activities are important for the oxidative activation of 3-ABA in livers, confirming recent results indicating that CYP-1A1 and -1A2 are mainly responsible for the metabolic activation of 3-ABA in human hepatic microsomes. No difference in DNA binding was found in kidney and bladder between null and wild-type mice, suggesting that cells in these extrahepatic organs have the metabolic capacity to oxidize 3-ABA to species forming the same 3-ABA-derived DNA adducts, independently from the CYP-mediated oxidation in the liver. We determined that different model peroxidases are able to catalyse DNA adduct formation by 3-ABA in vitro. Horseradish peroxidase (HRP), lactoperoxidase (LPO), myeloperoxidase (MPO), and prostaglandin H synthase (PHS) were all effective in activating 3-ABA in vitro, forming DNA adducts qualitatively similar to those formed in vivo in mice treated with 3-ABA and to those found in DNA reacted with N-hydroxy-3-aminobenzanthrone (N-OH-ABA). Collectively, these results suggest that both CYPs and peroxidases may play an important role in metabolizing 3-ABA to reactive DNA adduct forming species. (c) 2005 Elsevier Ireland Ltd. All rights reserved
    Type of Publication: Journal article published
    PubMed ID: 15885895
    Signatur Availability
    BibTip Others were also interested in ...
  • 9
    Keywords: APOPTOSIS ; CELLS ; CELL ; PATHWAY ; PATHWAYS ; TOXICITY ; SYSTEM ; DEATH ; NF-KAPPA-B ; ACTIVATION ; DNA ; 3-aminobenzanthrone ; 3-nitrobenzanthrone ; CARCINOGENESIS ; DIESEL EXHAUST ; ENVIRONMENTAL CONTAMINANT 3-NITROBENZANTHRONE ; PHOSPHORYLATION ; cytokines ; MOUSE ; CELL-DEATH ; genetics ; DAMAGE ; HUMAN ACETYLTRANSFERASES ; METABOLIC-ACTIVATION ; POLYCYCLIC AROMATIC-HYDROCARBONS ; DNA-DAMAGE ; NETHERLANDS ; TRANSLOCATION ; FLOW-CYTOMETRY ; AKT ; CYTOKINE ; MAPK ; SCIENCE ; ADDUCT FORMATION ; cell death ; DNA damage ; DNA ADDUCT ; ERK ; CARCINOGEN 3-NITROBENZANTHRONE ; AIR-POLLUTANT 3-NITROBENZANTHRONE ; Genetic ; IMMUNE ; 3-Ammobenzanthrone ; LUNG EPITHELIAL-CELLS
    Abstract: 3-Nitrobenzanthrone (3-NBA) is a mutagenic and carcinogenic environmental pollutant found in diesel exhaust and urban air pollution. In the present work we have characterised the effects of 3-NBA and its metabolite 3-aminobenzanthrone (3-ABA) on cell death and cytokine release in mouse hepatoma Hepa1c1c7 cells. These effects were related to induced DNA damage and changes in cell signalling pathways. 3-NBA resulted in cell death and caused most DNA damage as judged by the amount of DNA adducts (P-32-postlabelling assay), single strand (ss)DNA breaks and oxidative DNA lesions (comet assay) detected. An increased phosphorylation of H2AX, chk1, chk2 and partly ATM was observed using flow cytometry and/or Western blotting. Both compounds increased phosphorylation of p53 and MAPKs (ERK, p38 and JNK). However, only 3-NBA caused an accumulation of p53 in the nucleus and a translocation of Bax to the mitochondria. The p53 inhibitor pifithrin-alpha inhibited 3-NBA-induced apoptosis, indicating that cell death was a result of the triggering of DNA signalling pathways. The highest phosphorylation of Akt and degradation of I kappa B-alpha (suggesting activation of NF-kappa B) were also seen after treatment with 3-NBA. In contrast 3-ABA increased IL-6 release, but caused little or no toxicity. Cytokine release was inhibited by PD98059 and curcumin, suggesting that ERK and NF-kappa B play a role in this process. in conclusion, 3-NBA seems to have a higher potency to induce DNA damage compatible with its cytotoxic effects, while 3-ABA seems to have a greater effect on the immune system. (C) 2009 Elsevier B.V. All rights reserved
    Type of Publication: Journal article published
    PubMed ID: 19941874
    Signatur Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...