Prolonged treatments of AZA or DAC in SKM-1 cells.

A, Cell proliferation was assayed using the CellTiter 96 Aqueous One Solution assay kit after treating SKM-1 cells for 7 days with different concentrations of AZA (red dotted line) or DAC (blue dashed line). The percentage of cell proliferation was calculated relative to the rate of proliferation in untreated cells, and obtained from the mean (± SEM) of three independent experiments. B, Probes targeting CGI regions were classified into hyper, intermediate or hypo methylation groups according to their log2-ratios obtained from microarray analysis (See materials and methods). Most probes were hypomethylated (>80% in all cases). The number of probes classified as intermediate or hypermethylated were reduced after AZA or DAC treatments. C, Principal Component Analysis (PCA) with data from 4 independent treatments (from 52915 probes selected by within-replicate variance).