Cell Plasticity & Epigenetics
It is generally accepted that tumours are subjected to a myriad of evolutionary constraints at their niche of origin and further within the ecosystems encountered while invading novel tissues. Thus, evolutionary forces shape cancer development on many levels, as progression of the disease is often correlated with the appearance of somatic mutations and the selection of genetic traits that eventually become beneficial to neoplastic growth and often prejudicial to the host. Indeed, often-acquired mutations alter growth control systems and obliterate cell death programs, ultimately granting mutated cells with replicative immortality at the expense of genetic instability. However, due to the variable nature of the selective pressure in a particular niche, stable somatic mutations arise only after recurrent encounters with a challenging force. This suggests that, though under heavy evolutionary constraints, genetic changes driving adaptation do not occur immediately and highlights the biological relevance of cancer cell plasticity during neoplastic evolution.