Laboratoire de recherche sur la régulation de la prolifération des cellules souches adultes

 

Patrick Narbonne

Université du Québec à Trois-Rivières [UQTR]

 

Domaine : organismes vivants

Programme Chercheurs-boursiers - Junior 1

Concours 2018-2019

Age has long been considered as the greatest risk factor for developing cancer, but according to recent evidence, it may actually be the total number of divisions stem cells execute over our life that really is the greatest cancer risk factor. Indeed, combined with a natural selection favouring enhanced growth and survival abilities, the accumulation of inherited random errors during cell division inevitably tends to turn all stem cells into cancer cells. Thus, the longer we live, the more our stem cells divide, the more they can progress towards unscheduled growth and eventually, tumorigenesis. Other cell types are typically short-lived or have a limited division potential, such that the risk that they transform to initiate a tumour is very low. The transformation of a stem cell into a cancer cell involves escaping from the in vivo mechanisms that prevent stem cells from proliferating beyond control. That stem cells taken outside of animals can readily proliferate indefinitely in vitro (in the absence of these in vivo inhibitory mechanisms) is a simple demonstration of this.

To understand cancer then, we need to define those in vivo mechanisms that keep stem cell proliferation under control. One such mechanism is linked to aging and progressively impairs all stem cell functions. Another ensures stem cells only divide when new differentiated cells are needed. Particularly interesting, the later mechanism has localized properties that could eventually be utilized to influence the activity of individual stem cell populations by drugs. We want to better define these highly conserved regulatory mechanisms efficiently in a highly manipulable invertebrate model. Our work could therefore greatly impact medical strategies in cancer prevention and treatment, as well as in regenerative medicine.