Analysis of Polycomb Epigenetic Marks in HeLa Spheroids

Biochemical composition of the nucleus affects both its physical properties and its morphology. In recent years, several studies demonstrated the formation of f-actin in the nuclei. These filaments intermingle with the chromatin fibers underlying the crucial role of the mechanical force in chromatin remodeling, being thus involved in transcription, differentiation, replication, and DNA repair. Given the suggested role of Ezh2 in the cross-talk between f-actin and chromatin, we describe here how to obtain HeLa cell spheroids and a method to perform immunofluorescence analysis of nuclear epigenetic marks in a 3D cell culture system.