DZNep inhibits cell growth and induces apoptosis in NKTL tumor cells. (A) Western blot analysis of NK tumor cells exposed to increasing concentrations of DZNep showed a dose-dependent decrease in EZH2 protein, a decrease in CCND1 protein, and PARP cleavage in response to DZNep treatment. Cells were treated with indicated concentration of DZNep for 48 hours. Actin was used as a loading control. (B) Reduction of CCND1 mRNAs in DZNep-treated cells. The RNA harvested from the cells at 48 hours after treatment with DZNep at 5 µM, reverse-transcribed, subjected to qPCR by using primers specific for CCND1. (C) Quantification of cell viability in KHYG and NKYS cells treated with DZNep. Data are mean ±standard deviation of 3 independent experiments. (D) The rescued effects by EZH2 or EZH2Δ overexpression on DZNep-induced cell growth inhibition. Control plasmid or EZH2-expressing plasmids were cotransfected with pMAX-GFP to NKYS cells. Cells were then cultured in the absence or presence of DZNep at 10 µM for 48 hours. The percentage of GFP+ live cells was accessed by a Tali image-based cytometer.