The pattern of gene expression and gene dose profiles of 6-Mercaptopurine- and 6-Thioguanine-resistant human leukemia cells

► We characterized the pattern of gene expression and aberrations in DNA copy number of 6-MP- and 6-TG-resistant cells. ► Two transporters were downregulated in both cell lines confirming their role in the uptake of thiopurines by cells. ► DNTT gene was expressed by 6-TG- and 6-MP-resistant cells at levels higher than wild-type cells. ► Specific inhibitors of DNTT gene might be developed into a novel class of antitumor agents.