title: Use of two-dimensional gel electrophoresis in predictive toxicology: identification of potential early protein biomarkers in chemically induced hepatocarcinogenesis.
abstract: Our current approach focused on the identification of potential early protein biomarker signatures which are indicative of the carcinogenic processes in rats exposed to 20 mg/kg of the liver carcinogen N-nitrosomorpholine (NNM). Treated liver was investigated at different timepoints. Therefore, proteins were separated by two-dimensional gel electrophoresis as a first step prior to identification of differentially expressed proteins by mass spectrometry. Proteomic analysis of liver samples after one day of exposure revealed significant upregulation of proteins involved in response to cellular stress induced by NNM (superoxide dismutase, heat shock protein 60, peroxiredoxin). Eighteen weeks after withdrawal of NNM, we were able to identify cancer-related proteins in rat liver bearing malignant, transformed cells (caspase-8 precursor, vimentin, Rho GDP dissociation inhibitor). Some of these proteins were already deregulated after three weeks of exposure indicating their potential usefulness as early predictive biomarkers for liver carcinogenicity (annexin A5, fructose-1,6-bisphosphatase). As regulatory toxicology approaches usually include the investigation of carcinogenicity in two-years studies in rodents, especially the detection of early protein biomarker signatures which precede the appearance of neoplasia, demonstrates the high potential of proteomics approaches to substantially reduce the time and costs of carcinogenicity testing.
authors.affiliation: Merck KGaA, Institute of Toxicology, Darmstadt, Germany.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Fella
authors.forename: Matthias
authors.initials: M
authors.lastname: Glückmann
authors.forename: Jürgen
authors.initials: J
authors.lastname: Hellmann
authors.forename: Michael
authors.initials: M
authors.lastname: Karas
authors.forename: Peter-Jürgen
authors.initials: PJ
authors.lastname: Kramer
authors.forename: Michaela
authors.initials: M
authors.lastname: Kröger
mesh_terms: D000818:Animals; D014408:Biomarkers, Tumor / Q000096:biosynthesis*; D015180:Electrophoresis, Gel, Two-Dimensional; D008114:Liver Neoplasms, Experimental / Q000139:chemically induced / Q000378:metabolism* / Q000473:pathology; D008297:Male; D009363:Neoplasm Proteins / Q000096:biosynthesis*; D009602:Nitrosamines / Q000494:pharmacology / Q000633:toxicity; D011237:Predictive Value of Tests; D011506:Proteins / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D014408:Biomarkers, Tumor; D009363:Neoplasm Proteins; D009602:Nitrosamines; D011506:Proteins; C002741:N-nitrosomorpholine