title: An inter-laboratory collaborative study by the Non-Genotoxic Carcinogen Study Group in Japan, on a cell transformation assay for tumour promoters using Bhas 42 cells.
abstract: The Bhas promotion assay is a cell culture transformation assay designed as a sensitive and economical method for detecting the tumour-promoting activities of chemicals. In order to validate the transferability and applicability of this assay, an inter-laboratory collaborative study was conducted with the participation of 14 laboratories. After confirmation that these laboratories could obtain positive results with two tumour promoters, 12-O-tetradecanoylphorbol-13-acetate (TPA) and lithocholic acid (LCA), 12 coded chemicals were assayed. Each chemical was tested in four laboratories. For eight chemicals, all four laboratories obtained consistent results, and for two of the other four chemicals, only one of the four laboratories showed inconsistent results. Thus, the rate of consistency was high. During the study, several issues were raised, each of which were analysed step-by-step, leading to revision of the protocol of the original assay. Among these issues were the importance of careful maintenance of mother cultures and the adoption of test concentrations for toxic chemicals. In addition, it is suggested that three different types of chemicals show positive promoting activity in the assay. Those designated as T-type induced extreme growth enhancement, and included TPA, mezerein, PDD and insulin. LCA and okadaic acid belonged to the L-type category, in which transformed foci were induced at concentrations showing growth-inhibition. In contrast, M-type chemicals, progesterone, catechol and sodium saccharin, induced foci at concentrations with little or slight growth inhibition. The fact that different types of chemicals similarly induce transformed foci in the Bhas promotion assay may provide clues for elucidating mechanisms of tumour promotion.
authors.affiliation: Chemistry Division, Kanagawa Prefectural Institute of Public Health, 1-3-1 Shimomachiya, Chigasaki, Kanagawa 253-0087, Japan. ohmori.n4yf@pref.kanagawa.jp
authors.forename: Kiyomi
authors.initials: K
authors.lastname: Ohmori
authors.forename: Makoto
authors.initials: M
authors.lastname: Umeda
authors.forename: Noriho
authors.initials: N
authors.lastname: Tanaka
authors.forename: Hiroki
authors.initials: H
authors.lastname: Takagi
authors.forename: Isao
authors.initials: I
authors.lastname: Yoshimura
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Sasaki
authors.forename: Shin
authors.initials: S
authors.lastname: Asasda
authors.forename: Ayako
authors.initials: A
authors.lastname: Sakai
authors.forename: Harumi
authors.initials: H
authors.lastname: Araki
authors.forename: Masumi
authors.initials: M
authors.lastname: Asakura
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Baba
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Fushiwaki
authors.forename: Shuichi
authors.initials: S
authors.lastname: Hamada
authors.forename: Nobuko
authors.initials: N
authors.lastname: Kitou
authors.forename: Tetsu
authors.initials: T
authors.lastname: Nakamura
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Nakamura
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Oishi
authors.forename: Satoshi
authors.initials: S
authors.lastname: Sasaki
authors.forename: Sawako
authors.initials: S
authors.lastname: Shimada
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Tsuchiya
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Uno
authors.forename: Masataka
authors.initials: M
authors.lastname: Washizuka
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yajima
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Yamamoto
authors.forename: Eiji
authors.initials: E
authors.lastname: Yamamura
authors.forename: Tomoko
authors.initials: T
authors.lastname: Yatsushiro
mesh_terms: D000826:Animal Testing Alternatives / Q000379:methods; D000818:Animals; D041702:BALB 3T3 Cells / Q000166:cytology / Q000187:drug effects*; D015197:Carcinogenicity Tests; D002273:Carcinogens / Q000032:analysis* / Q000633:toxicity*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002471:Cell Transformation, Neoplastic / Q000139:chemically induced*; D004305:Dose-Response Relationship, Drug; D007564:Japan; D008095:Lithocholic Acid / Q000494:pharmacology / Q000633:toxicity; D051379:Mice; D015203:Reproducibility of Results; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013997:Time Factors
chemical_list: D002273:Carcinogens; D008095:Lithocholic Acid; D013755:Tetradecanoylphorbol Acetate