Abstract
The convergence between a statistical mechanics and biological approach in elucidating some basic features of cell differentiation opens new avenues of research in gene expression regulation and holds some promises in terms of a re-differentiation approach to a cancer cure. The message emerging from two recent papers by the authors of the present communication follows very simple basic lines. The time-honored concept of homeostasis, at the very basis of physiology, is in action even at the microscopic level of gene expression regulation, where a continuous (relatively small) oscillation of gene expression is mandatory for keeping alive the substantial stability of the gene expression profile typical of a given cell type. This mechanism of stability, when oscillation exceeds a certain threshold, is responsible for the spreading of a large-scale perturbation invading the entire genome and eventually giving rise to cell fate change. The material basis of this model was discovered in the onset of a global reorganisation of chromatin driven by fusion-splitting dynamics of pericentromeric associated domains that, by selective folding/unfolding of chromatin, allows for a global scale re-arrangement of genome expression.