Weight of evidence approach using a TK gene mutation assay with human TK6 cells for follow-up of positive results in Ames tests: a collaborative study by MMS/JEMS.

ABSTRACT:

Background

Conflicting results between bacterial mutagenicity tests (the Ames test) and mammalian carcinogenicity tests might be due to species differences in metabolism, genome structure, and DNA repair systems. Mutagenicity assays using human cells are thought to be an advantage as follow-up studies for positive results in Ames tests. In this collaborative study, a thymidine kinase gene mutation study (TK6 assay) using human lymphoblastoid TK6 cells, established in OECD TG490, was used to examine 10 chemicals that have conflicting results in mutagenicity studies (a positive Ames test and a negative result in rodent carcinogenicity studies).

Results

Two of 10 test substances were negative in the overall judgment (20% effective as a follow-up test). Three of these eight posi

SUBMITTER: Yasui M 

PROVIDER: S-EPMC7937321 | biostudies-literature | 2021 Mar

REPOSITORIES: biostudies-literature