The carcinogenic potential of compounds is a crucial aspect in human hazard and risk assessment of substances. Among the various alternatives developed for carcinogenicity prediction, the cell transformation assays (CTAs) have been shown to closely model some key stages of the in vivo carcinogenesis process. Similar to previously validated in vitro CTAs, the CTA in Bhas 42 cells aims at predicting carcinogenic potential. Based on the results of a validation study coordinated by Hadano Research Institute (HRI) Food and Drug Safety Center (FDSC) and other published data, the Bhas 42 CTA protocol (including the 6-well and 96-well plate versions) was considered to be sufficiently standardised, transferable, reproducible between laboratories and relevant to support the identification of potential carcinogenicity of substances. Following independent scientific peer review by the EURL ECVAM’s Scientific Advisory Committee (ESAC) and having considered the input from regulators, stakeholders, international partners and the general public, EURL ECVAM concluded that the CTA in Bhas 42 cells shows promise for inclusion within weight of evidence or integrated testing strategy approaches to assess carcinogenic potential or to support chemical category formation and read-across. Thus EURL ECVAM recommends that an OECD test Guideline be developed. In addition, further investigations on the capability of the assay to detect tumour promoters would provide useful information on mode of action of carcinogens for risk assessment purposes.JRC.I.5-Systems Toxicolog
