Induction of CTA and costimulatory molecule expression in hematopoietic tumor cell lines after exposure to AZA and VPA. (A) Myeloid cell lines HL60, KG1a, Kasumi, K562, U937, and NB4 and multiple myeloma cell lines U266 and JJN3 were treated with AZA (AZA) at the indicated concentrations for 72 hours and then for a further 24 hours in fresh medium or medium containing 1mM VPA. Quantitative real-time reverse transcription–polymerase chain reaction was used to determine changes in CTA expression by the comparative C_t (ΔΔC_t) method. Transcript levels of each gene were expressed as a percentage of the highest expression achieved within a set of treatments for each cell line, and the TMeV program was used to generate heat maps. Expression levels for Kasumi, HL60, KG1a, U937, NB4, K562, JJN3, and U266 cell lines are displayed in vertically descending order for each gene studied. (B) Quantitation of CD86⁺ cells as determined by flow cytometry in AML cell lines treated in triplicate with 500nM AZA for 72 hours or 1mM VPA for 24 hours and labeled with PE-CD86 antibody (Serotec).