Verification of the BALB/c 3T3 cell transformation assay after improvement by using an ITES-medium

• Published in: Toxicology in vitro Vol. 17; no. 4; pp. 489 - 496
• Main Authors: Kajiwara, Yoshitsugu, Ajimi, Syozo
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-08-2003
• Subjects: 3T3 Cells; Animals; BALB/c 3T3 cells; Carcinogenicity Tests - methods; Carcinogens - toxicity; Cell Transformation, Neoplastic - drug effects; Culture Media - chemistry; Dose-Response Relationship, Drug; Improved cell transformation assay; ITES-medium; Mice; Mice, Inbred BALB C; Nongenotoxic carcinogens; Reproducibility of Results; BALB/c 3T3 cells; Nongenotoxic carcinogens; ITES-medium; Improved cell transformation assay; EPA
• ISSN: 0887-2333; 1879-3177
• DOI: 10.1016/S0887-2333(03)00050-X

We carried out the first-step verification study on our ITES-medium-improved BALB/c 3T3 cell transformation assay. In order to estimate its potential use as a short-term screening method for putative carcinogens, 31 chemicals were tested in the improved transformation assay. The test chemicals consisted of 18 carcinogens and 13 noncarcinogens. The present improved transformation assay did not use an exogenous metabolizing system. Data analysis was carried out on 34 chemicals, including assay data for three chemicals reported previously by the authors. As a result, the improved transformation assay showed a concordance of 73.5% with a rodent bioassay, a sensitivity for carcinogens of 71.4%, and a specificity for detection of noncarcinogens of 76.9%. The improved transformation assay detected all of the genotoxic carcinogens, and five of 11 nongenotoxic carcinogens as positive. It can be expected that the improved transformation assay will be able to detect not only genotoxic carcinogens with high probability but also approximately 50% of nongenotoxic carcinogens within about 3 weeks. Hence, these preliminary findings suggest that our improved transformation assay will be a reliable and useful short-term test procedure of screening for potential carcinogens, and it encourages us to conduct further experiments on many carcinogens and noncarcinogens.