Micronuclei and Gene Mutation at tk Locus Induced by Cyclophosphamide in TK6 Human Lymphoblastoid Cells / 环境与健康杂志

ABSTRACT

Objective To establish a method to investigate micronuclei (MN) and gene mutation at the heterozygous thymidine kinase (tk) locus induced by environmental mutagens in TK6 human lymphoblastiod cells. Methods TK6 cells were used to detect cytotoxic response, MN and mutation frequency at tk locus induced by cyclophosphomide (CP) after treatment with S9 mixture for 4 h. Results Exposure to CP for 4 h decreased relative survival (RS), induced both MN and TK mutation in a concetration-dependent manner. The maximum induction of MN and TK mutations were 8.8 and 15.7 times compared with those of control. Two distinct phenotypic colonies of TK mutants were generated, namely tk-NG and tk-SG mutant colonies but mainly the latter. Conclusion CP induced both MN and TK mutation in TK6 cells. TK6 cells can be used as an in vitro assay system to assess cytogenetic damage and gene mutation at tk locus of environmental chemicals.