RESUMO
Human promyelocytic HL60 cells can be differentiated into macrophagelike cells by treatment with 12Otetra decanoylphorbol13acetate (TPA). Certain 5' upstream regions of the zinc finger protein (ZNF)encoding genes contain duplicated GGAA motifs, which are frequently found in the TPAresponding gene promoter regions. To examine transcriptional responses to TPA, 5'flanking regions of human zinc finger CCCHtype containing, antiviral, ZNF252, ZNF343, ZNF555, ZNF782 and zinc finger nfx1type containing 1 (ZNFX1) genes were isolated by polymerase chain reaction (PCR) and ligated into a multiplecloning site of the pGL4.10[luc2] vector. Transient transfection and a luciferase assay revealed that the ZNFX1 promoter most prominently responded to the TPA treatment. Deletion and point mutation experiments indicated that the duplicated GGAA motif in the 100bp region positively responded to TPA. In addition, reverse transcriptionquantitative PCR and western blotting showed that the mRNA and protein of ZNFX1 accumulate during the differentiation of HL60 cells. These results indicated that expression of the TPAinducible ZNFX1 gene, which belongs to the group of interferonresponsive genes, is regulated by the cisaction of the duplicated GGAA motif.