Issues

This image shows H3K9 trimethylation (H3K9me3) of nuclear histone proteins as a marker for cellular senescence. Immunofluorescence picture of HepG2 human hepatoblastoma cells treated with 20 μmol/L 5-aza-2′-deoxycytidine (5-aza-dC, Dacogen) for a 72-hour time period. Cells were stained using DAPI, α-tubulin, and α-trimethylation of H3K9 (histone protein H3K9me3). The green spots within the cellular nucelus represent the presence of the senescence marker H3K9me3 as a cellular response to the treatment with the DNA-methyltransferase inhibitor 5-aza-2′-deoxycytidine. For more details, see the article by Venturelli and colleagues on page 2226.