Fig. 6

HAT1 increases PD-L1 expression through BRD4 in pancreatic cancer cells. a and b, PANC-1 cells were infected with lentivirus vectors expressing control or HAT1-specific shRNAs. Forty-eight hours postinfection, the cells were treated with or without JQ1 (3 μM) for another 24 h. Cells were harvested for Western blotting (a) and RT-qPCR analysis (b). The data shown are the mean values ± SD from three replicates. ns, not significant; **, P < 0.01. c and d, PANC-1 cells were infected with the indicated constructs. After 48 h, the cells were harvested for Western blotting (c) and RT-qPCR analysis (d). The data shown are the mean values ± SD from three replicates. ns, not significant; **, P < 0.01. e and f, PANC-1 cells were infected with lentivirus vectors expressing control or BRD4-specific shRNAs. Forty-eight hours postinfection, the cells were transfected with pcDNA 3.1 or Flag-HAT1. After 24 h, the cells were harvested for Western blotting (e) and RT-qPCR analysis (f). The data shown are the mean values ± SD from three replicates. ns, not significant; ***, P < 0.01. g, UCSC Genome Browser screenshots of the BRD4 ChIP-seq profiles at the PD-L1 gene locus in C4–2 cells reported previously [27]. h, PANC-1 cells were infected with lentivirus vectors expressing control or HAT1-specific shRNAs. Forty-eight hours postinfection, the cells were treated with or without JQ1 (3 μM) for another 24 h. The cells were harvested for ChIP-qPCR analysis (h). The data shown are the mean values ± SD from three replicates. ns, not significant; *, P < 0.05; **, P < 0.01;***, P < 0.001. i, A hypothetical model depicting the catalysis of histone H4 acetylation by HAT1 and the BRD4 complex binding to the acetylated H4 to initiate the transcription of PD-L1