2011
Gábelová, Alena; Valovičová, Zuzana; Mesárošová, Monika; Trilecová, Lenka; Hrubá, Eva; Marvanová, Soňa; Krčmár, Pavel; Milcová, Alena; Schmuczerová, Jana; Vondráček, Jan; Machala, Miroslav; Topinka, Jan
Genotoxicity of 7H-dibenzo[c,g]carbazole and its tissue-specific derivatives in human hepatoma HepG2 cells is related to CYP1A1/1A2 expression. Journal Article
In: Environmental and molecular mutagenesis, vol. 52, no. 8, pp. 636–645, 2011, ISSN: 1098-2280 0893-6692, (Place: United States).
Abstract | Links | BibTeX | Tags: Base Sequence, Blotting, Carbazoles/*toxicity, Cell Survival/drug effects, Chromosome-Defective/chemically induced/statistics & numerical data, Comet assay, Cytochrome P-450 CYP1A1/*genetics, Cytochrome P-450 CYP1A2/*genetics, DNA adducts, DNA Breaks, Dose-Response Relationship, Drug, Hep G2 Cells, Histones/metabolism, Humans, Micronuclei, Micronucleus Tests, Mitotic Index, Molecular Sequence Data, Mutagens/*toxicity, Phosphorylation, Real-Time Polymerase Chain Reaction, Tumor Suppressor Protein p53/metabolism, Western
@article{gabelova_genotoxicity_2011,
title = {Genotoxicity of 7H-dibenzo[c,g]carbazole and its tissue-specific derivatives in human hepatoma HepG2 cells is related to CYP1A1/1A2 expression.},
author = {Alena Gábelová and Zuzana Valovičová and Monika Mesárošová and Lenka Trilecová and Eva Hrubá and Soňa Marvanová and Pavel Krčmár and Alena Milcová and Jana Schmuczerová and Jan Vondráček and Miroslav Machala and Jan Topinka},
doi = {10.1002/em.20664},
issn = {1098-2280 0893-6692},
year = {2011},
date = {2011-10-01},
journal = {Environmental and molecular mutagenesis},
volume = {52},
number = {8},
pages = {636–645},
abstract = {The goal of this study was to investigate the genotoxicity of 7H-dibenzo[c,g]carbazole (DBC), a ubiquitous environmental pollutant, and its methyl derivatives, 5,9-dimethylDBC (DiMeDBC), a strict hepatocarcinogen, and N-methylDBC (N-MeDBC), a specific sarcomagen in human hepatoma HepG2 cells, and to infer potential mechanisms underlying the biological activity of particular carcinogen. All dibenzocarbazoles, regardless the tissue specificity, induced significant DNA strand break levels and micronuclei in HepG2 cells; though a mitotic spindle dysfunction rather than a chromosome breakage was implicated in N-MeDBC-mediated micronucleus formation. While DBC and N-MeDBC produced stable DNA adducts followed with p53 protein phosphorylation at Ser-15, DiMeDBC failed. A significant increase in DNA strand breaks following incubation of exposed cells with a repair-specific endonuclease (Fpg protein) suggested that either oxidative DNA damage or unstable DNA-adducts might underlie DiMeDBC genotoxicity in human hepatoma cells. DiMeDBC and N-MeDBC increased substantially also the amount of CYP1A1/2 expression in HepG2 cells. Pretreatment of cells with substances affecting AhR-mediated CYP1A family of enzymes expression; however, diminished DiMeDBC and N-MeDBC genotoxicity. Our data clearly demonstrated differences in the mechanisms involved in the biological activity of DiMeDBC and N-MeDBC in human hepatoma cells; the genotoxicity of these DBC derivatives is closely related to CYP1A1/2 expression.},
note = {Place: United States},
keywords = {Base Sequence, Blotting, Carbazoles/*toxicity, Cell Survival/drug effects, Chromosome-Defective/chemically induced/statistics & numerical data, Comet assay, Cytochrome P-450 CYP1A1/*genetics, Cytochrome P-450 CYP1A2/*genetics, DNA adducts, DNA Breaks, Dose-Response Relationship, Drug, Hep G2 Cells, Histones/metabolism, Humans, Micronuclei, Micronucleus Tests, Mitotic Index, Molecular Sequence Data, Mutagens/*toxicity, Phosphorylation, Real-Time Polymerase Chain Reaction, Tumor Suppressor Protein p53/metabolism, Western},
pubstate = {published},
tppubtype = {article}
}
The goal of this study was to investigate the genotoxicity of 7H-dibenzo[c,g]carbazole (DBC), a ubiquitous environmental pollutant, and its methyl derivatives, 5,9-dimethylDBC (DiMeDBC), a strict hepatocarcinogen, and N-methylDBC (N-MeDBC), a specific sarcomagen in human hepatoma HepG2 cells, and to infer potential mechanisms underlying the biological activity of particular carcinogen. All dibenzocarbazoles, regardless the tissue specificity, induced significant DNA strand break levels and micronuclei in HepG2 cells; though a mitotic spindle dysfunction rather than a chromosome breakage was implicated in N-MeDBC-mediated micronucleus formation. While DBC and N-MeDBC produced stable DNA adducts followed with p53 protein phosphorylation at Ser-15, DiMeDBC failed. A significant increase in DNA strand breaks following incubation of exposed cells with a repair-specific endonuclease (Fpg protein) suggested that either oxidative DNA damage or unstable DNA-adducts might underlie DiMeDBC genotoxicity in human hepatoma cells. DiMeDBC and N-MeDBC increased substantially also the amount of CYP1A1/2 expression in HepG2 cells. Pretreatment of cells with substances affecting AhR-mediated CYP1A family of enzymes expression; however, diminished DiMeDBC and N-MeDBC genotoxicity. Our data clearly demonstrated differences in the mechanisms involved in the biological activity of DiMeDBC and N-MeDBC in human hepatoma cells; the genotoxicity of these DBC derivatives is closely related to CYP1A1/2 expression.
2005
Harper, Richart W.; Xu, Changhong; Soucek, Karel; Setiadi, Henny; Eiserich, Jason P.
A reappraisal of the genomic organization of human Nox1 and its splice variants. Journal Article
In: Archives of biochemistry and biophysics, vol. 435, no. 2, pp. 323–330, 2005, ISSN: 0003-9861, (Place: United States).
Abstract | Links | BibTeX | Tags: *DNA Primers, *Genome, Alternative Splicing, Base Sequence, Caco-2 Cells, Computational Biology, Cultured, Epithelial Cells/enzymology, human, Humans, Hydrogen Peroxide/metabolism, Isoenzymes/genetics/metabolism, Male, Molecular Sequence Data, NADPH Oxidase 1, NADPH Oxidases/*genetics/metabolism, Prostate/enzymology, Reactive Oxygen Species/metabolism, Sequence Alignment, Superoxides/metabolism, Tumor Cells
@article{harper_reappraisal_2005,
title = {A reappraisal of the genomic organization of human Nox1 and its splice variants.},
author = {Richart W. Harper and Changhong Xu and Karel Soucek and Henny Setiadi and Jason P. Eiserich},
doi = {10.1016/j.abb.2004.12.021},
issn = {0003-9861},
year = {2005},
date = {2005-03-01},
journal = {Archives of biochemistry and biophysics},
volume = {435},
number = {2},
pages = {323–330},
abstract = {The recent discovery of non-phagocytic NAD(P)H oxidases belonging to the Nox family of enzymes sharing extensive homology to the leukocyte NAD(P)H oxidase has revolutionized our understanding of oxidative signaling related to fundamental biological processes and disease states. One form of this enzyme, Nox1, is a growth factor-responsive enzyme that catalyzes formation of the reactive oxygen species superoxide (O(2)(-)) and hydrogen peroxide (H(2)O(2)). Its expression is linked to a number of biological responses including cellular proliferation, angiogenesis, and activation of cellular signaling pathways. Whereas early published studies have described three distinct isoforms of Nox1, the current body of literature fails to adequately recognize this notion. Also, functional differences between isoforms remain relatively unexplored. Herein, we report that expression of human Nox1 is restricted to two distinct isoforms derived from a single gene; that is, the full-length gene product and a shorter spliced variant which lacks one of the NAD(P)H binding domains. We have developed PCR primer sets that distinguish between the two forms of Nox1 in several human cell lines. We could not find evidence for expression of the shortest reported form of Nox1 (NOH-1S), previously identified as a proton channel, and the absence of paired splice sites in the gene suggests that it represents a reverse transcriptase artifact. A survey of the scientific literature reveals that the majority of studies related to Nox1 do not utilize molecular strategies that would adequately discern between the two Nox1 variants. The current literature suggest the two identified isoforms of human Nox1 (which we have named Nox1-L and Nox1-S) may be functionally distinct. Future studies related to Nox1 will benefit from establishing the identity of the Nox1 isoform expressed and the functions attributed to each variant.},
note = {Place: United States},
keywords = {*DNA Primers, *Genome, Alternative Splicing, Base Sequence, Caco-2 Cells, Computational Biology, Cultured, Epithelial Cells/enzymology, human, Humans, Hydrogen Peroxide/metabolism, Isoenzymes/genetics/metabolism, Male, Molecular Sequence Data, NADPH Oxidase 1, NADPH Oxidases/*genetics/metabolism, Prostate/enzymology, Reactive Oxygen Species/metabolism, Sequence Alignment, Superoxides/metabolism, Tumor Cells},
pubstate = {published},
tppubtype = {article}
}
The recent discovery of non-phagocytic NAD(P)H oxidases belonging to the Nox family of enzymes sharing extensive homology to the leukocyte NAD(P)H oxidase has revolutionized our understanding of oxidative signaling related to fundamental biological processes and disease states. One form of this enzyme, Nox1, is a growth factor-responsive enzyme that catalyzes formation of the reactive oxygen species superoxide (O(2)(-)) and hydrogen peroxide (H(2)O(2)). Its expression is linked to a number of biological responses including cellular proliferation, angiogenesis, and activation of cellular signaling pathways. Whereas early published studies have described three distinct isoforms of Nox1, the current body of literature fails to adequately recognize this notion. Also, functional differences between isoforms remain relatively unexplored. Herein, we report that expression of human Nox1 is restricted to two distinct isoforms derived from a single gene; that is, the full-length gene product and a shorter spliced variant which lacks one of the NAD(P)H binding domains. We have developed PCR primer sets that distinguish between the two forms of Nox1 in several human cell lines. We could not find evidence for expression of the shortest reported form of Nox1 (NOH-1S), previously identified as a proton channel, and the absence of paired splice sites in the gene suggests that it represents a reverse transcriptase artifact. A survey of the scientific literature reveals that the majority of studies related to Nox1 do not utilize molecular strategies that would adequately discern between the two Nox1 variants. The current literature suggest the two identified isoforms of human Nox1 (which we have named Nox1-L and Nox1-S) may be functionally distinct. Future studies related to Nox1 will benefit from establishing the identity of the Nox1 isoform expressed and the functions attributed to each variant.