Anti-ATL effects of DNA demethylating agents in vitro. (A) Chemical structures and metabolic pathways of AZA, DAC, OR-1200 (OR12), and OR-2100 (OR21). (B) Fifty percent inhibitory concentration values of each compound in HTLV-1–infected T-cell lines treated with them for 4 days, determined by CCK-8 assay. Data are expressed as means of 3 independent experiments. (C) DNA methylation levels in LINE-1 regions determined by bisulfite pyrosequencing of HTLV-1–infected T-cell lines treated with the indicated compounds for 4 days. Data are expressed as means of 3 independent experiments with SD. (D) Immunoblots showing the levels of DNMT1 protein reduction in HTLV-1–infected T-cell lines after treatment with the indicated compounds for 4 days. Graphs show the mean fold-decrease (± SD) in DNMT1 protein compared with untreated cells, based on data from 3 independent experiments. (E) Gene expression levels of CD7, FHIT, C2orf40, THEMIS, LAIR1, and RNF130 in MT-1 and MT-2 cells after treatment with the indicated compounds.