Profile: Senior Scientist, SickKids Research Institute
Department: Surgery, University of Toronto
Lab: Dirks Lab
Our laboratory is interested in the connection between stem cell biology and human brain cancer. We have recently demonstrated that brain tumors, in humans and in some mouse models, are organized as a functional hierarchy with growth dependent on relatively rare cells that have stem cell properties. Most of the bulk of the brain tumor cells are not capable of sustaining tumor growth. The brain tumor stem cells can be prospectively enriched by sorting for cell surface markers and can be functionally analysed in vitro and in vivo. These cells, and the molecular pathways that regulate them, are important potential therapeutic targets for future brain tumor therapy. Recently, we have used chemical biological screens to identify agents that suppress normal and brain tumor stem cell proliferation. These agents are possible new drugs for human brain tumors, and as the chemicals act as probes of stem cell function, also reveal additional pathways that may regulate the self renewal or differentiation of neural stem cells. We are now also focusing on identifying the molecular pathways which determine neural stem cell and brain tumor stem cell function, using a variety of different approaches. We are also studying whether brain tumors arise from transformation of a normal stem cell, or from more differentiated cells, using human and mouse models.