Figure 8.

The effect of methylation on the binding of SP1 to CpG#18-20. Labeled oligonucleotides containing unmethylated, singly-methylated, or triple-methylated CpG sites were mixed with nuclear extract derived from 16HBE14o- (A) or CFBE41o- (B) cells and subjected to EMSA. Competition analysis was carried out by adding unlabeled oligonucleotides (lanes 3, 7 and 11) to the reaction solution. Supershift analysis to detect SP1-specific binding was performed using an SP1 antibody (lanes 4, 8 and 12). Arrows indicate the SP1-containing complexes (SP1) and the supershifted SP1 (SS). Bands derived from probes containing 3 methylated CpGs are indicated by (#).