Lausanne (Switzerland): Two to three metres of DNA can fit inside a single cell, thus it can only be stored by being wound tightly into coils. The answer is chromatin, a compound of DNA encased in histone-like proteins. This complex gradually folds into the multi-layered arrangement of loops, domains, and compartments that we know as chromosomes in the 3D world. Any issues with chromatin structure can have negative implications, including the emergence of cancer because the architecture of chromatin is directly linked to gene expression and the proper functioning of the cell.
A common event in around 30 per cent of all human cancers is "whole genome doubling" (WGD), whereby the entire set of chromosomes in a cell is duplicated. WGD leads to genomic instability inside the cell, which can result in chromosomal alterations and other mutations that contribute to the development of cancer. Now, a team of researchers led by Elisa Oricchio at EPFL and Giovanni Ciriello at UNIL, has uncovered a new clue as to how WGD drives cancer. In a study published in Nature, the scientists show that WGD can affect the 3D organization of the chromatin inside the cell through a phenomenon called "loss of chromatin segregation".