title: Cisplatin upregulates Saccharomyces cerevisiae genes involved in iron homeostasis through activation of the iron insufficiency-responsive transcription factor Aft1.
abstract: The response of Saccharomyces cerevisiae to cisplatin was investigated by examining variations in gene expression using cDNA microarrays and confirming the results by reverse transcription polymerase chain reaction (RT-PCR). The mRNA levels of 14 proteins involved in iron homeostasis were shown to be increased by cisplatin. Interestingly, the expression of all 14 genes is known to be regulated by Aft1, a transcription factor activated in response to iron insufficiency. The promoter of one of these genes, FET3, has been relatively well studied, so we performed a reporter assay using the FET3 promoter and showed that an Aft1 binding site in the promoter region is indispensable for induction of transcription by cisplatin. The active domain of Aft1 necessary for activation of the FET3 promoter by cisplatin is identical to the one required for activation by bathophenanthroline sulfonate, an inhibitor of cellular iron uptake. Furthermore, we found that cisplatin inhibits the uptake of (55)Fe(II) into yeast cells. These findings suggest that cisplatin activates Aft1 through the inhibition of iron uptake into the cells, after which the expression of Aft1 target genes involved in iron uptake might be induced.
authors.affiliation: Laboratory of Molecular and Biochemical Toxicology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Kimura
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Ohashi
authors.forename: Akira
authors.initials: A
authors.lastname: Naganuma
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology; D001665:Binding Sites / Q000235:genetics; D002570:Ceruloplasmin / Q000235:genetics / Q000378:metabolism; D002945:Cisplatin / Q000494:pharmacology*; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects / Q000235:genetics*; D006706:Homeostasis / Q000187:drug effects* / Q000235:genetics; D007501:Iron / Q000378:metabolism*; D000090463:Iron Deficiencies; D007763:Lac Operon / Q000235:genetics; D020411:Oligonucleotide Array Sequence Analysis; D010618:Phenanthrolines / Q000494:pharmacology; D011401:Promoter Regions, Genetic / Q000235:genetics; D017434:Protein Structure, Tertiary / Q000187:drug effects / Q000235:genetics; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D015854:Up-Regulation / Q000187:drug effects / Q000235:genetics
chemical_list: C090297:AFT1 protein, S cerevisiae; D000970:Antineoplastic Agents; D010618:Phenanthrolines; D012333:RNA, Messenger; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; C002850:4,7-diphenylphenanthroline sulfonate; D007501:Iron; D002570:Ceruloplasmin; C085513:FET3 protein, S cerevisiae; D002945:Cisplatin