MSP unmethylated–methylated amplicon ratio of genes of interest increases during treatment with decitabine in MLL-r cell lines. PCR primers for anticipated post–bisulfite-methylated (M) and unmethylated (U) promoter sequences for the genes DAPK1, CCR6, and HRK were used to determine their methylation status. MSP was performed on DNA from each cell line before treatment (time 0) with decitabine and again at 72 hours of treatment with 2 and 4μM decitabine. In addition, densitometry was performed on all amplicons and the unmethylated amplicon–methylated amplicon (U:M) densitometry ratios were calculated, with a smaller ratio indicating a lower degree of methylation. The graph demonstrates that for DAPK1, CCR6, and HRK the time 0 U:M ratios are generally smaller for the MLL-r cell lines ([A] SEMK2, [B] KOPN8, and [C] HB1119) than for the MLL-wt cell lines ([D] NALM6, [E] 380, and [F] TANOUE) and there is a posttreatment trend toward increased U:M ratios in the MLL-wt cell lines, indicating a demethylating effect of decitabine treatment. This phenomenon was not seen in the MLL-wt cell lines.