title: JaCVAM-organized international validation study of the in vivo rodent alkaline comet assay for detection of genotoxic carcinogens: II. Summary of definitive validation study results.
abstract: The in vivo rodent alkaline comet assay (comet assay) is used internationally to investigate the in vivo genotoxic potential of test chemicals. This assay, however, has not previously been formally validated. The Japanese Center for the Validation of Alternative Methods (JaCVAM), with the cooperation of the U.S. NTP Interagency Center for the Evaluation of Alternative Toxicological Methods (NICEATM)/the Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM), the European Centre for the Validation of Alternative Methods (ECVAM), and the Japanese Environmental Mutagen Society/Mammalian Mutagenesis Study Group (JEMS/MMS), organized an international validation study to evaluate the reliability and relevance of the assay for identifying genotoxic carcinogens, using liver and stomach as target organs. The ultimate goal of this exercise was to establish an Organisation for Economic Co-operation and Development (OECD) test guideline. The study protocol was optimized in the pre-validation studies, and then the definitive (4th phase) validation study was conducted in two steps. In the 1st step, assay reproducibility was confirmed among laboratories using four coded reference chemicals and the positive control ethyl methanesulfonate. In the 2nd step, the predictive capability was investigated using 40 coded chemicals with known genotoxic and carcinogenic activity (i.e., genotoxic carcinogens, genotoxic non-carcinogens, non-genotoxic carcinogens, and non-genotoxic non-carcinogens). Based on the results obtained, the in vivo comet assay is concluded to be highly capable of identifying genotoxic chemicals and therefore can serve as a reliable predictor of rodent carcinogenicity.
authors.affiliation: Mitsubishi Tanabe Pharma Co., Chiba, Japan. Electronic address: Uno.Yoshifumi@ma.mt-pharma.co.jp.
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Uno
authors.affiliation: National Institute of Health Sciences, Tokyo, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Kojima
authors.affiliation: Kobe University Hospital, Kobe, Japan(1).
authors.forename: Takashi
authors.initials: T
authors.lastname: Omori
authors.affiliation: Joint Research Centre of the European Commission, Ispra, Italy.
authors.forename: Raffaella
authors.initials: R
authors.lastname: Corvi
authors.affiliation: National Institute of Health Sciences, Tokyo, Japan.
authors.forename: Masamistu
authors.initials: M
authors.lastname: Honma
authors.affiliation: Innovative Toxicology Consulting, LLC, FL, USA.
authors.forename: Leonard M
authors.initials: LM
authors.lastname: Schechtman
authors.affiliation: National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA.
authors.forename: Raymond R
authors.initials: RR
authors.lastname: Tice
authors.affiliation: Covance Laboratories Ltd., North Yorkshire, UK.
authors.forename: Carol
authors.initials: C
authors.lastname: Beevers
authors.affiliation: Janssen Research & Development, Beerse, Belgium.
authors.forename: Marlies
authors.initials: M
authors.lastname: De Boeck
authors.affiliation: Huntingdon Life Sciences, Cambs, UK.
authors.forename: Brian
authors.initials: B
authors.lastname: Burlinson
authors.affiliation: Integrated Laboratory Systems, Inc., NC, USA.
authors.forename: Cheryl A
authors.initials: CA
authors.lastname: Hobbs
authors.affiliation: Sumitomo Chemical Co. Ltd., Osaka, Japan.
authors.forename: Sachiko
authors.initials: S
authors.lastname: Kitamoto
authors.affiliation: Merck Research Laboratories, PA, USA.
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Kraynak
authors.affiliation: Health Canada, Ontario, Canada.
authors.forename: James
authors.initials: J
authors.lastname: McNamee
authors.affiliation: Hatano Research Institute, Food Drug Safety Center, Kanagawa, Japan.
authors.forename: Yuzuki
authors.initials: Y
authors.lastname: Nakagawa
authors.affiliation: BioReliance, MD, USA.
authors.forename: Kamala
authors.initials: K
authors.lastname: Pant
authors.affiliation: Novartis, Institutes for BioMedical Research, Basel, Switzerland.
authors.forename: Ulla
authors.initials: U
authors.lastname: Plappert-Helbig
authors.affiliation: AstraZeneca R&D, Cheshire, UK.
authors.forename: Catherine
authors.initials: C
authors.lastname: Priestley
authors.affiliation: LSI Medience,(2) Ibaraki, Japan.
authors.forename: Hironao
authors.initials: H
authors.lastname: Takasawa
authors.affiliation: The Institute of Environmental Toxicology, Ibaraki, Japan.
authors.forename: Kunio
authors.initials: K
authors.lastname: Wada
authors.affiliation: Bayer HealthCare AG, Wuppertal, Germany.
authors.forename: Uta
authors.initials: U
authors.lastname: Wirnitzer
authors.affiliation: Kinki University, Osaka, Japan.
authors.forename: Norihide
authors.initials: N
authors.lastname: Asano
authors.affiliation: Boehringer Ingelheim Pharmaceuticals Inc., CT, USA.
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Escobar
authors.affiliation: St. George's, University of London, London, UK.
authors.forename: David
authors.initials: D
authors.lastname: Lovell
authors.affiliation: National Institute of Health Sciences, Tokyo, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Morita
authors.affiliation: University of Shizuoka, Shizuoka, Japan.
authors.forename: Madoka
authors.initials: M
authors.lastname: Nakajima
authors.affiliation: National Institute of Health Sciences, Tokyo, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Ohno
authors.affiliation: Biosafety Research Center, Foods, Drugs and Pesticides, Shizuoka, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Hayashi
mesh_terms: D000818:Animals; D002273:Carcinogens / Q000032:analysis*; D020552:Comet Assay / Q000379:methods* / Q000592:standards*; D004249:DNA Damage; D005020:Ethyl Methanesulfonate; D008099:Liver / Q000187:drug effects; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013270:Stomach / Q000187:drug effects
chemical_list: D002273:Carcinogens; D005020:Ethyl Methanesulfonate
keywords: Comet assay; Genotoxicity; In vivo; JaCVAM; Rodent; Validation study