title: An assay method for the prediction of tumor promoting potential of chemicals by the use of Bhas 42 cells.
abstract: It has become an important task to develop a simple in vitro method for the detection of non-genotoxic carcinogens, among which tumor promoters are included. Bhas 42 cells are v-Ha-ras-transfected BALB/c 3T3 cells and are regarded as initiated cells in the 2-stage transformation paradigm. We designed a method for detecting tumor promoters by the use of Bhas 42 cells at advanced passage generation. In this method, the cells are cultured in six-well plates for 17 days during which test chemicals are added in the medium for 11 days from days 3 to 14. The end-point of the assay is the induction of transformed foci. When the tumor promoter TPA was used, a significant number of transformed foci were induced concentration-dependently, whereas only a few foci were observed in control cultures. When various chemicals were examined by the method, a reasonable correlation was observed with the reported tumor-promoting ability in animal experiments. We propose that the Bhas 42 cell transformation method is practical and useful for the detection of tumor promoters.
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: Kiyoshi
authors.initials: K
authors.lastname: Sasaki
authors.forename: Shin
authors.initials: S
authors.lastname: Asada
authors.forename: Noriho
authors.initials: N
authors.lastname: Tanaka
authors.forename: Makoto
authors.initials: M
authors.lastname: Umeda
mesh_terms: D000818:Animals; D041702:BALB 3T3 Cells; D015197:Carcinogenicity Tests / Q000379:methods*; D002471:Cell Transformation, Neoplastic; D004305:Dose-Response Relationship, Drug; D011905:Genes, ras / Q000502:physiology*; D051379:Mice; D014162:Transfection