A High-Throughput Cell Transformation Assay Applicable to Automation for Detecting Potential Chemical Carcinogens Using Bhas 42 Cells

The cell transformation assay using Bhas 42 cells (Bhas 42 CTA) was developed as an in vitro test method for predicting the carcinogenicity of chemicals. The assay can detect tumor promoters as well as tumor initiators. The usefulness of Bhas 42 CTA has been previously verified using 6-well culture plates (6-well method). Meanwhile, we have developed an alternative method using 96-well culture plates (96-well method) in anticipation of its potential utility for high-throughput automated applications. The assay procedures are fundamentally the same between the 6-well and 96-well methods. This study has been carried out to confirm the comparability of the 6-well and 96-well methods for chemically induced transformation. 3-Methylcholanthrene and 12-O-tetradecanoylphorbol 13-acetate were found to yield similar dose-dependent responses between the 6-well and 96-well methods. The 96-well method was subsequently tested using 32 chemicals that had already been tested by the 6-well method. The positive and negative judgments determined from the 96-well method were concordant with those determined from the 6-well method, except for sodium arsenite. Overall, it was concluded that the results obtained using the 6-well method and the 96-well method were analogous.