title: Micronucleus formation by single and mixed heavy metals/loids and PAH compounds in HepG2 cells.
abstract: Humans and other organisms are exposed to multi-chemical mixtures including commonly found carcinogens such as polycyclic aromatic hydrocarbons (PAHs) and heavy metal/loids. The joint effects of these chemicals as beyond the binary mixtures have not been well characterised. In this study, we evaluated the combined genotoxicity of mixtures of PAHs and heavy metal/loids containing benzo(a)pyrene (B[a]P), naphthalene (Nap), phenanthrene (Phe), pyrene (Pyr), arsenic (As), cadmium (Cd) and chromium (Cr) using in vitro micronucleus (MN) test in HepG2 cells. The induction of aryl hydrocarbon receptor (AhR) by single and mixed PAHs was also measured. The results indicated that individual and mixed Nap, Phe and Pyr did not induce significant MN frequencies. PAHs mixture containing B[a]P and B[a]P alone caused significant but similar level of MN frequencies. The same pattern was found in their AhR induction. Individual metal/loids induced significant cytostasis and MN formation of which Cd was found the most potent inducer. Mixture of metal/loids caused higher frequency of MN suggesting a possible additive effect among metal/loids. In addition, binary mixture of metal/loids and B[a]P, namely As/B[a]P, Cd/B[a]P and Cr/B[a]P, increased MN formation. Mixture of Cd and B[a]P induced the highest level of MN. Exposure of cells to the mixture containing B[a]P and Cd/Cr/As at lower concentration (0.25 µM) resulted in significant MN frequency, the level of which was equal to that by Cd/B[a]P at 1.0 µM. The results of the study suggested that an additive effect may exist between PAHs and heavy metal/loids in a compound- and concentration-dependent manner. The compounds with highest potencies of genotoxicity in the mixture seem dominant as driving sources in the final combined genotoxicity of PAHs and heavy metal/loids.
authors.affiliation: National Research Centre for Environmental Toxicology-Entox, The University of Queensland, 39 Kessels Road, Coopers Plains, Brisbane 4108, Australia, Cooperative Research Centre for Contamination Assessment and Remediation of the Environment, Adelaide 5095, Australia and.
authors.forename: Cheng
authors.initials: C
authors.lastname: Peng
authors.affiliation: National Research Centre for Environmental Toxicology-Entox, The University of Queensland, 39 Kessels Road, Coopers Plains, Brisbane 4108, Australia, Cooperative Research Centre for Contamination Assessment and Remediation of the Environment, Adelaide 5095, Australia and.
authors.forename: Sasikumar
authors.initials: S
authors.lastname: Muthusamy
authors.affiliation: National Research Centre for Environmental Toxicology-Entox, The University of Queensland, 39 Kessels Road, Coopers Plains, Brisbane 4108, Australia, Cooperative Research Centre for Contamination Assessment and Remediation of the Environment, Adelaide 5095, Australia and.
authors.forename: Qing
authors.initials: Q
authors.lastname: Xia
authors.affiliation: National Research Centre for Environmental Toxicology-Entox, The University of Queensland, 39 Kessels Road, Coopers Plains, Brisbane 4108, Australia, Cooperative Research Centre for Contamination Assessment and Remediation of the Environment, Adelaide 5095, Australia and.
authors.forename: Vincent
authors.initials: V
authors.lastname: Lal
authors.affiliation: Department of Environmental Toxicology, University of California, Davis, CA 95616, USA.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Denison
authors.affiliation: National Research Centre for Environmental Toxicology-Entox, The University of Queensland, 39 Kessels Road, Coopers Plains, Brisbane 4108, Australia, Cooperative Research Centre for Contamination Assessment and Remediation of the Environment, Adelaide 5095, Australia and j.ng@uq.edu.au.
authors.forename: Jack C
authors.initials: JC
authors.lastname: Ng
mesh_terms: D056945:Hep G2 Cells; D006801:Humans; D019216:Metals, Heavy / Q000633:toxicity*; D048629:Micronuclei, Chromosome-Defective / Q000139:chemically induced*; D011084:Polycyclic Aromatic Hydrocarbons / Q000633:toxicity*; D018336:Receptors, Aryl Hydrocarbon / Q000187:drug effects
chemical_list: D019216:Metals, Heavy; D011084:Polycyclic Aromatic Hydrocarbons; D018336:Receptors, Aryl Hydrocarbon