Fig. 4: PCAF serves as a histone lactyltransferase for H3K18 in PDAC.

A Molecular docking simulated the binding affinities of PCAF for acetyl-CoA and lactyl-CoA. B Co-IP was performed to confirm the interaction between H3K18la and PCAF in PANC1 and KPC cells. PCAF and H3K18la were detected on the same gel. C, D Western blot analysis demonstrates the level of H3K18la in PDAC cells with or without the treatment of PCAF inhibitors (bromosporine or Embelin). Histone H3 and H3K18la blots are from parallel-processed separate gels (size conflict) with samples from the same experiment. E Western blot analysis demonstrates the level of H3K18la in PDAC cells following the knockdown of Pcaf. Histone H3, PCAF, β-actin and H3K18la blots are from parallel-processed separate gels with samples from the same experiment. F Western blots of in vitro histone acetylation or lactylation assay, the samples as indicated. Blots are from parallel-processed separate gels with samples from the same experiment. G, H Relative Cxcl1 RNA and protein levels with the vehicle or bromosporine treatment were analyzed by qRT-PCR and ELISA (n = 3 independent experiments), respectively. I Relative Cxcl1 RNA levels after Pcaf knockdown were analyzed by qRT-PCR (n = 3 independent experiments). J A schematic diagram showing the orthotopic tumor construction in C57BL/6 J mice (n = 5 mice per group in one experiment, 2 × 10⁶ KPC-luc cells per mouse) with or without bromosporine treatment. K, L Image and weights of the orthotopic tumors in the experimental groups from (J) at the end of the experiments (n = 5 mice per group). M Lactylation levels of H3K18 and PanK in orthotopic tumors with or without bromosporine treatment were detected by western blot (n = 4 biologically independent samples per group). Histone H3, H3K18la, and PanKla blots are from parallel-processed separate gels (size conflict) with samples from the same experiment. N Serum CXCL1 levels in mice with or without bromosporine treatment were measured by ELISA (n = 5 mice per group). O–R Tumor-infiltrating neutrophils, CD8⁺ T cells, GZMB⁺CD8⁺ T cells, and PD-1⁺CD8⁺ T cells isolated from the orthotopic tumors were analyzed using flow cytometry. Representative graphs of flow cytometry (left panel) and statistical analysis of the cell ratio (right panel) (n = 5 mice per group). S The migratory abilities of neutrophils co-incubated with the culture medium supernatant from shNTC/Pcaf PDAC cells treated with recombinant CXCL1 were analyzed by counting the penetrated cell numbers (n = 3 biologically independent samples). T Representative IHC images stained by CXCL1 or H3K18la antibody (scale bar = 100 μm, left panel), correlation analysis of H-scores of CXCL1 and H3K18la in PDAC samples (n = 21 patients, right panel). Data represent mean ± SEM. Statistical analysis was conducted using the two-tailed unpaired Student’s t test (G–I, L, and N–S) and two-tailed Pearson’s correlation analysis (T). Unless otherwise indicated, all western blots had three independent experimental repetitions with consistent results. Source data are provided as a Source Data file.