Figure 4.

Effect of 5-azacytidine on DNA methylation state of the tissue transglutaminase promoter and the gene expression. (A) HeLa cells were treated with 5 μM 5-azacytidine for 3 days or 6 days. On day 6 after 5-azacytidine treatment, the genomic DNA was isolated from control cells (lanes 1 and 2), 3-day treated cells (lanes 3 and 4), and 6-day treated cells (lanes 5 and 6) and subjected to the digestion with HindIII plus MspI (lanes 1, 3, and 5) or HindIII plus HpaII (lanes 2, 4, and 6), followed by Southern blot analysis. (B) HeLa cells were treated with 5.0 μM 5-azacytidine for 3 days. On day 6, the cell extracts were prepared from both control and drug-treated cells and subjected to transglutaminase assay.