Expression profile of colon cancer cell lines after 5-aza-dC treatment. Levels of PXR, VDR and CYP3A4 transcripts in (a), LS180; (b), Caco-2; (c), HCT116; (d), LoVo; (e), HT29; and (f), SW48 cells. Cells were treated with 5-aza-2'-deoxycytidine (0, 0.5 or 5 μM). The vertical axis indicates a relative transcript level (ratio to cells without 5-aza-dC treatment). Numbers in italics indicate relative transcript levels that were over the maximum scale on the vertical axis. The transcripts indicated by * (PXR exon 5-6 transcript in SW48 cells and CYP3A4 transcript in HCT116 cells) were not detected and we estimated the minimum detectable levels among gradually diluted calibration samples.