Vimentin is a member of the intermediate filament family, and the NF-κB binding site is located in the human vimentin promoter. To gain insight into the role of NF-κB in the regulation of the vimentin gene during 12-O-tetradecanoylphorbol-13-acetate (TPA)-dependent differentiation of HL-60 cells, the effect of pyrrolidine dithiocarbamete (PDTC) has been investigated using Northern blot hybridization and DNA mobility shift assay. PDTC inhibited macrophage-like morphologic change of HL-60 cells by TPA. TPA-dependent increase of vimentin mRNA level was decreased in a time- and dose-dependent manner by pretreatment with PDTC. One DNA-protein complex was formed by DNA mobility shift assay when the NF-κB or AP-1 binding sites were incubated with nuclear extract prepared from TPA-treated HL-60 cells, but no protein bound in control HL-60 cells without TPA. After PDTC pretreatment, NF-κB binding activity vanished but AP-1 binding activity was unchanged. Taken together, these results suggest that NF-κB may be an essential transacting factor for transcriptional repression of the vimentin gene by PDTC during TPA-dependent differentiation of HL-60 cells.

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