P57KIP2 methylation in ALL cell lines.

(A) Map of the promoter-associated CpG island of p57KIP2 in relation to exon 1 and its transcription start site (arrow). Each vertical line represents a CpG site. (B) Combined bisulfite restriction PCR analysis of p57KIP2 in ALL cell lines. The restricted band (M) represents the methylated allele. (C) RT-PCR analysis of p57KIP2 gene expression in methylated and unmethylated cell lines. + indicates with reverse transcriptase (RT); −, without. Bottom blots show GAPDH control. (D) RT-PCR analysis of p57KIP2 before and after 5-aza-2′-deoxycytidine (AzadC) exposure.