Simplified acid extraction and quantification of histones in human tumor cells.

Histones are essential nuclear proteins that package eukaryotic DNA into chromosomes, play a vital role in gene regulation, DNA replication, DNA repair and chromosome condensation. Understanding histone modifications is crucial for grasping biological and disease-related processes. Specific alterations in histone modifications serve as sensitive and selective biomarkers for conditions like cancer, impacting both tumor and immune cells and affecting their interactions. Indeed, the interest in histone modifications is growing in the field of tumor immunology and immunotherapy. Different techniques have been developed to characterize histone proteins and their modifications. Here, we present a simple acid extraction protocol to identify and quantify histones. The workflow described here can be used to detect and measure histone proteins or specific residues of histone, even capturing changes resulting from treatment with epigenetic drugs (Epi-drugs) or other drugs in in different human cancer cell line models.