Figure 5.

Specificity of GTC TFO inhibition of Sp1 and Sp3 binding to myc P2 probe. Gel-shift assays used double-stranded probes containing either the TFO target and flanking sequence (Myc P2) or a polypurine/polypyrimidine tract and flanking sequence from the c-myc P1 promoter region (Myc P1). (A) Antibody pre-incubation with the P1 probe was done as described in Figure 3. (B) Pre-incubation of P1 (left) or P2 (right) probes with 1 µM Myc GTC or GTC-C and subsequent protein-binding assays and electrophoresis were done as described in Figure 6. Arrowheads and arrows indicate Sp1 and Sp3 protein complexes, respectively. U, unbound probe.