Induction of MAGE-A1 protein expression in myeloma and AML cell lines by AZA and VPA. (A) NB4 (i) and JJN3 (ii) cell lines were treated as indicated, and the induction of MAGE-A1 protein expression was examined by Western blotting with the anti–MAGE-A antibody (clone MA454; Sigma-Aldrich). Blots were stripped and reprobed for β-actin (mouse monoclonal anti–β-actin, ac-74; Sigma-Aldrich) as a loading control. (B) Time-course studies showing durability of azacitidine/sodium valproate (AZA/VPA)–induced expression changes. KG1a cells were treated with AZA/VPA as before (d4) and then passaged 1:10 in fresh media once per week for 2 weeks before protein was harvested for MAGE-A1 expression analysis. AZA indicates azacitidine; d0, baseline; d4, day 4; and d18, day 18.