title: Different responses to 5-fluoraouracil in mutagenicity and gene expression between two human lymphoblastoid cell lines with or without TP53 mutation.
abstract: Human lymphoblastoid TK6 and WTK-1 cells are widely used to detect mutagens in vitro. TK6 cells have wild-type TP53 alleles, while WTK-1 cells have one allele of mutated TP53. Both cells were treated with 5-fluorouracil (5-FU), and gene mutation assay and micronucleus assay were performed to clarify the differential response related to the TP53 gene status. The effects of 5-FU on gene expression were assessed by microarray and quantitative RT-PCR analyses. In WTK-1 cells, 5-FU increased the frequency of cells with micronucleus and mutation. In TK6 cells, frequency of cells with micronucleus was increased but the mutation frequency was not. The cytotoxicity induced by 5-FU was more prominent in TK6 cells than in WTK-1 cells. Analysis of gene expression showed that the genes involved in the TP53 pathway were up-regulated in TK6 cells but not in WTK-1 cells. The differential responses to 5-FU between these cell lines appeared to be due to the difference in the TP53 gene status, thus providing a molecular basis for the bioassays using these cell lines in the toxicology field. Our results indicate that the clinical efficacy of 5-FU chemotherapy may depend on the TP53 genotype.
authors.affiliation: Tokushima Research Center, Taiho pharmaceutical Co., Ltd., Japan. hiro-oka@taiho.co.jp
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Oka
authors.forename: Mamoru
authors.initials: M
authors.lastname: Ouchida
authors.forename: Takuya
authors.initials: T
authors.lastname: Kondo
authors.forename: Fumio
authors.initials: F
authors.lastname: Morita
authors.forename: Kenji
authors.initials: K
authors.lastname: Shimizu
mesh_terms: D045744:Cell Line, Tumor; D005472:Fluorouracil / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects*; D016158:Genes, p53; D006801:Humans; D015162:Micronucleus Tests; D016296:Mutagenesis / Q000187:drug effects*; D009152:Mutagenicity Tests; D020411:Oligonucleotide Array Sequence Analysis; D060888:Real-Time Polymerase Chain Reaction; D016159:Tumor Suppressor Protein p53 / Q000235:genetics* / Q000378:metabolism
chemical_list: D016159:Tumor Suppressor Protein p53; D005472:Fluorouracil