Pluripotency rush! Molecular cues for pluripotency, genetic reprogramming of adult stem cells, and widely multipotent adult cells

In the last few years, pluripotent stem cells have been the objective of intense investigation efforts. These cells are of paramount therapeutic interest, since they could be utilized: as in vitro models of disease, for pharmaceutical screening purposes, and for the regeneration of damaged organs. Over the years, pluripotent cells have been cultured from teratomas, the inner cell mass, and primordial germ cells. Accumulating informations have partially decrypted the molecular machinery responsible for the maintenance of a very primitive state, permitting the reprogramming of differentiated cells. Although the debate is still open, an extreme excitement is arising from two strictly related possibilities: pluripotent cells could be obtained from adult tissues with minimal manipulations or very rare pluripotent cells could be identified in adult tissues. This intriguing option will trigger new researches aimed both at identifying the possible biological role of pluripotent adult stem cells and at exploiting their potential clinical use. The present review article will summarize current knowledge of the molecular cues for pluripotency but also discusses whether pluripotent stem cells could be obtained from adult tissues. (C) 2009 Elsevier Inc. All rights reserved.