Fig. 2

Global methylation changes in S3 cells. a DMH microarray detected differences in genome-wide methylation between S3 and SiHa cells (S1 and S2) and between 5-aza-treated and -untreated S3 cells (S3 and S4). These four sets of data were then subject to unsupervised hierarchical clustering analysis. Blocks I, II, and III designate the main clustering blocks. b Validation of gene methylation and expression differences between S3 and SiHa cells. Three genes (NEUROG2, PVT1, and DLX2) with identified methylation differences from a were validated by qMSP, and changes in their expression were detected by qRT-PCR. Three genes (Casp8AP2, GSTP1, and MLH1) with known methylation and expression differences between S3 and SiHa cells were used as controls. c These loci were hypermethylated in S3 cells, and their methylation was reversed (upper panel) and their expression restored (lower panel) by treatment with 5-aza. d Immunostaining confirmed the restoration of Casp8AP2 expression after treatment with 5-aza