Reprogramming of global histone modifications by garcinol and curcumin. (A) Nuclear staining of MCF7 breast cancer cells with antibodies detecting pan acetyl H3 (top panels) or pan acetyl H4 (bottom panels). Control shows typical staining in the absence of inhibitors (vehicle only), and the effect of treatment with HAT inhibitors at the indicated concentrations are also shown. Scalebar: 10 μm. (B&C) Immunostaining of MCF7 cells following treatment with the indicated concentrations of curcumin or garcinol for 24 hours. Vehicle control is also shown. Histone PTM-specific antibodies were used to reveal H3K18Ac, H4K16Ac and H3K9Ac levels in response to treatment. Scalebar: 10μm. (D) Western blots on whole cell extracts of MCF7 cells. Cell extracts were prepared following 24 hours culture in the presence of HAT inhibitors (or vehicle control) at the indicated concentrations. Specific antibodies were used to detect bulk levels of H3K18Ac, H4K16Ac and H3K9Ac. Densitometry measurements were performed using Image J software . The level of each histone PTM in controls (vehicle only, normalised to a loading control) was set to 1. (E) Western blots showing bulk levels of H3K18Ac in whole cell extracts of U2OS and SaOS2 osteosarcoma cells following exposure to 10 μM or 20 μM curcumin or garcinol (as indicated in increasing scale). Actin loading controls are also shown, and the data were quantified by Image J as in (D).