FIG. 6.

The IL-8 promoter contains two responsive sites for Zta-induced activation. (A) The IL-8 promoter used in the reporter gene assay is illustrated. The DNA sequences of AP-1 and ZRE sites in the promoter are shown underlined. Mutations introduced into these two sites (AP-1m and ZREm) are also indicated. (B) NPC-TW01 cells were cotransfected with the indicated reporter plasmids (a series of pIL-8-Luc) and the effecter plasmids (vector plasmid or a Zta-expressing plasmid). At 36 h posttransfection, the luciferase assay was performed. The Zta-induced fold activation for each reporter (luciferase activity for the Zta transfectant versus that for its vector control) is provided. Shown is a representative result from three independent experiments. (C) A similar reporter gene assay was performed by using the pIL-8(−333/+44)-Luc-derived plasmids carrying mutations at ZRE and/or AP-1 sites. The experimental procedures and the way of data presentation are the same as that in panel B.