The narrow-spectrum HDAC inhibitor entinostat enhances NKG2D expression without NK cell toxicity, leading to enhanced recognition of cancer cells - PubMed (original) (raw)

Figure 1. Dose response and kinetics of entinostat induction of NKG2D in fresh primary NK cells and of NKG2D ligands in tumor cell lines

(A) Dose response of MICA/B expression in HCT-15 cells 24 h after incubation with entinostat (0, 0.1, 1, and 10 μM). (B) Kinetics of MICA/B expression in HCT-15 cells 24, 48, and 72 h after incubation with 0.1 μM entinostat. (C) Dose response of NKG2D expression in primary human NK cells 24 h after incubation with entinostat (0, 0.1, 1, and 10 μM). (D) Kinetics of NKG2D expression on NK cells 24, 48, and 72 h after incubation with 0.1 μM entinostat. Flow histograms: Gray shaded, isotype control antibody. Thin gray line, control cells treated with DMSO (A, C) or assessed at time 0 h (B, D). Black thin, medium, or thick lines represent 0.1, 1, and 10 μM respectively (A, C) or 24, 48, and 72 h respectively (B, D). (C) and (D) are representative of experiments with five different NK cell donors. (E) Increase in NKG2D ligands in HCT-15, SaOS2, COL, LM7, CCH-OS-D, and CCH-OS-T 24 h after incubation with 0.1 μM entinostat. (F) Increase in NKG2D, NKp30, NKp44, and NKp46 after 24 h incubation with 0.1 μM entinostat in freshly-isolated NK cells, or (G) in NK cells expanded with IL-2 and IL-21. (H) Expression of MICA/B and ULBP (pooled) on normal human cells in culture for 24 h with or without 0.1 μM entinostat. (I) Change in expression of NKG2D after 24 h incubation with different concentrations of entinostat (31.2, 62.5, 125, 250, 500, 1000, 2000 and 4000ng/mL), romidepsin (0.195, 0.39, 0.78, 1.56, 3.12, 6.25, 12.5, 25, 50 and 100ng/mL), or PCI-24781(7.8, 15.6, 31.2, 62.5, 125, 250, 500 and 1000ng/mL). (J) Expression of NKG2D ligands in tumor cells as determined by MFI after 24h culture at 21% or 1% O2, with or without 0.1 μM entinostat. Mean ± SEM are shown (E, F, G, I).