Figure 1
C646 inhibits histone H3 acetylation and proliferation of pancreatic cancer cells. (A) Endogenous H3K9Ac, H3K18Ac, and H3K27Ac expression in human pancreatic cancer cell lines. Histone H3 acetylation levels were quantified in four pancreatic cancer cell lines, Hs766T, MIAPaCa2, PSN1, and Panc1, by Western blotting. (B) C646 treatment (10–50 µM) compared with the DMSO vehicle control by Western blotting of PSN1 and MIAPaCa2 cells. Histone H3K9, H3K18, and H3K27 acetylation were downregulated as the C646 concentration increased. Experiments were performed in duplicate. Error bars represent mean ± SD. *p < 0.05. (C, D) Cell viability following C646 treatment of PSN1 and MIAPaCa2 cells by WST-8 assay (C) and BrdU incorporation assay (D). (C) Cells were seeded at 1.5 × 103 per well and incubated overnight, after which titrated doses of C646 (10–50 µM) were added. Cell viability assays were performed every 24 h up to 72 h. (D) C646 treatment was for 72 h. Each data point was evaluated as relative % ratio normalized to vehicle control. Each experiment was performed in duplicate. Error bars represent mean ± SD. *p < 0.05 by one-way ANOVA with post hoc Dunnett's test. (E) Left panel, clonogenic cell survival after C646 treatment relative to DMSO vehicle control for PSN1 and MIAPaCa2 cells. Cancer cells were treated with 30 µM C646 or DMSO for nine hours and then incubated for seven days in fresh media. The ability to form colonies after C646 treatment was significantly decreased in both cell lines. *p < 0.05 vs control. Middle panel, dose-dependent effects on the clonogenic assay for MIAPaCa2 cells (*p < 0.05 vs control by one-way ANOVA with post hoc Dunnett's test). Right panel, representative image of clonogenic cell survival assay on treatment of MIAPaCa2 cells with different doses of C646. Error bars represent mean ± SD.
