Fig. 3.

Determinations of Sp1 Binding to the hCtr1 and Sp1 promoters under various treatments by the ChIP assay. A, vector-transferred SCLC or hCtr1-DN-transfected cells were treated with 100 μM CuSO₄ for 16 h followed by the ChIP assay of Sp1 binding to hCtr1 and Sp1 promoters as indicated. Input refers to total chromatin DNA before immunoprecipitation with anti-Sp1 antibody or nonimmune immunoglobulin IgG. B, the ChIP assay was performed in empty-vector- and hCtr1-wt transfected cells treated with or without 40 μM TM for 16 h. C, ChIP assay of Sp1 binding to the Sp1 and hCtr1 promoters in HEK293 cells transfected with the empty vector, Sp1-encoding, and hCtr1-encoding recombinants for 16 h as indicated. D, Schematic diagram showing the summary of results presented in A to C. Details can be found in Fig. 1I.