title: The stress response resolution assay. II. Quantitative assessment of environmental agent/condition effects on cellular stress resolution outcomes in epithelium.
abstract: Cellular stress responses consist of a complex network of pathways and linked processes that, when perturbed, are postulated to have roles in the pathogenesis of various human diseases. To assess the impact of environmental insults upon this network, we developed a novel stress response resolution (SRR) assay for investigation of cellular stress resolution outcomes and the effects of environmental agents and conditions thereupon. SRR assay-based criteria identified three distinct groups of surviving cell clones, including those resembling parental cells, those showing Hprt/HPRT mutations, and a third type, "Phenotype-altered" clones, that occurred predominantly in cells pretreated with a chemical mutagen, was heterogeneous in nature, and expressed significant alterations in cell morphology and/or function compared with parental cells. Further evaluation of Phenotype-altered clones found evidence of various alterations that resembled epithelial-to-mesenchymal transition, phenotype switching, checkpoint dysfunction, senescence barrier bypass, and/or epigenetic reprogramming. Phenotype-altered clones were found to occur spontaneously in a cell line with a mutator phenotype, to represent the major surviving clone type in a variation of the SRR assay, and to be tumorigenic in nude mice. Assessment of SRR assay final results showed that pretreatment with a chemical mutagen induced significant changes in cellular stress response prosurvival capacity, in damage avoidance versus damage tolerance stress resolution outcomes, and in the damage burden in the final surviving cell populations. Taken together, these results support the conclusion that use of the SRR assay can provide novel insights into the role of environmental insults in the pathogenesis of cancer and other human diseases.
authors.affiliation: Burlington HC Research Group, Jericho, VT 05465, USA. bhcrg@ymail.com
authors.forename: Dale M
authors.initials: DM
authors.lastname: Walker
authors.forename: Janice A
authors.initials: JA
authors.lastname: Nicklas
authors.forename: Vernon E
authors.initials: VE
authors.lastname: Walker
mesh_terms: D000666:Amphotericin B / Q000494:pharmacology / Q000633:toxicity; D000818:Animals; D059447:Cell Cycle Checkpoints / Q000187:drug effects; D016923:Cell Death / Q000187:drug effects; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D048430:Cell Shape / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004249:DNA Damage; D004305:Dose-Response Relationship, Drug; D004847:Epithelial Cells / Q000187:drug effects* / Q000502:physiology; D004848:Epithelium / Q000187:drug effects / Q000378:metabolism; D005038:Ethylnitrosourea / Q000494:pharmacology / Q000633:toxicity; D006150:Guanine Nucleotides / Q000494:pharmacology / Q000633:toxicity; D006801:Humans; D007041:Hypoxanthine Phosphoribosyltransferase / Q000235:genetics; D019259:Lamivudine / Q000494:pharmacology / Q000633:toxicity; D051379:Mice; D009153:Mutagens / Q000494:pharmacology / Q000633:toxicity*; D009154:Mutation / Q000187:drug effects; D010641:Phenotype; D013312:Stress, Physiological / Q000187:drug effects*; D013873:Thionucleotides / Q000494:pharmacology / Q000633:toxicity; D018675:Toxicity Tests; D015215:Zidovudine / Q000494:pharmacology / Q000633:toxicity
chemical_list: D006150:Guanine Nucleotides; D009153:Mutagens; D013873:Thionucleotides; C003964:6-thioguanylic acid; D019259:Lamivudine; D015215:Zidovudine; D000666:Amphotericin B; D007041:Hypoxanthine Phosphoribosyltransferase; D005038:Ethylnitrosourea