Decitabine treatment results in T-cell–mediated lysis in vitro and T-cell trafficking to tumors in vivo. (A-C) Chromium-release assay in the indicated cell lines incubated with EBV-CTLs reactive to EBNA3C, EBNA3A, or LMP1 as labeled. BL cells were treated with decitabine at 50 nM (Rael) or 250 nM (Mutu I) or vehicle control for 72 hours. Controls are as follows: (A) autologous dendritic cells with A0201 HLA loaded with EBNA3C peptide (positive control) and autologous dendritic cells with A0201 HLA alone (negative control), (B) EBV-transformed autologous BLCL (positive control) and autologous dendritic cells (negative control), and (C) EBV-transformed autologous BLCL (positive control) and autologous phytohemagglutinin-activated blasts (negative control). ** P < .01, ***P < .001, ****P < .0001. (D-E) IHC for EBNA2 and CD8 in xenograft tumors as indicated. Microscope, Olympus BX 43 microscope; camera, Jenoptik ProgResCF; software, ProgRes Mac Capture Pro, 2013. Original magnification ×600 with a 60/0.80 objective lens. (F) Bioluminescence in Rael-luciferase xenografts. *P < .05. (G) IHC for CD8 in Mutu I xenografts in the indicated treatment cohorts. Upon engraftment, Mutu I xenograft mice were randomized to treatment with decitabine at 1 mg/kg daily × 3 days or vehicle control followed by EBV-CTLs twice weekly vs control with 4 mice in each cohort. Mice were humanely sacrificed at the time of tumor growth >2000 mm³ or at day 18 to evaluate for T-cell trafficking to tumor.