Fig. 8.

HDAC inhibition induces differentiation of LMP1-positive NPC-derived cells. a CNE1-TetOn-LMP1 and CNE1-TetOn-Vector cells were treated by 100 ng/ml Dox for 24 hours, and then exposed to JNJ (0, 2, 20, and 200 nM), FK228 (0, 0.5, 5, and 50 nM), or Chidamide (0, 0.5, 1, and 3 μM) for 24 hours. Expression of CEBPA, differentiation and stem-like markers were examined by immunoblotting. b C666-1 cells were treated with Chidamide (0, 0.5, 1, and 3 μM) for 48 hours. Expression of CEBPA, differentiation and stem-like markers were examined by immunoblotting. c, d CNE1-TetOn-LMP1 and CNE1-TetOn-Vector cells were treated by 100 ng/ml Dox for 24 hours, and then exposed to 200 nM JNJ, 10 nM FK228 or 1 μM Chidamide for 24 hours and immunofluorescence staining was performed with indicated antibodies. e SA-β-gal staining was performed and the β-gal-positive staining cells were counted. f Experimental setup for FK228 treatment. CNE1-TetOn-LMP1 and CNE1-TetOn-Vector cells were injected into nude mice subcutaneously with continuous Dox administration. Mice were treated with FK228 by intraperitoneal perfusion from day 27 (120 μg/kg, every two days). g, h The images of dissected tumors at the endpoint of the experiment were shown and growth curve was plotted by measuring the relative tumor volume at indicated day. i Immunohistochemistry was performed in tumors from g for differentiation markers. Representative images were shown. Statistics (d–e, and h), significance: *P < 0.05, **P < 0.01, ***P < 0.001; two-tailed Student’s t-tests (d, e); one-way ANOVA with Bonferroni correction (h)