For more information, visit:

Dirks Lab

Brief Biography

Graduated from Queen's University Medical School in Kingston, Ontario in 1989. Completed PhD in Molecular and Cellular Pathology in 1997 at the University of Toronto and completed neurosurgery training at the University of Toronto 1998 (Fellow of the Royal College of Surgeons, Canada, 1998). Paedatric Neurosurgery Fellowship training at Necker Enfants Malades (Paris) in 1998.

Appointed to Neurosurgical Staff at The Hospital for Sick Children in the University of Toronto in 1998. Appointed to the Research Institute Developmental Biology Program in 1999. Established Research Laboratory to study brain tumours in the Arthur and Sonia Labatt Brain Tumor Research Centre at The Hospital for Sick Children in 1999.

Clinical Care Activities 

My clinical interests lie with the entire spectrum of paediatric neurosurgical practice, with emphasis on the surgical treatment of childhood brain tumours and brain vascular malformations.

Research Interests

• brain tumours
• cancer stem cells
• neural stem cells
• neural development

Research Activities 

The long term goal of Dr. Peter Dirks' research program is to determine if a normal neural stem cell or progenitor cell is transformed into a brain tumour. Two different approaches are being used in his lab to study this question.

One approach involves a study of primary human brain tumours obtained from neurosurgical operations to determine if stem cell populations exist in brain tumours. The group is interested in finding out if there a small population of cancer cells in a brain tumour that uniquely has the ability to maintain the tumour or can all brain tumour cells drive tumour growth?

Dr. Dirks' lab has recently isolated and characterized a cancer stem cell from human brain tumours of different phenotypes that express neural stem cell markers and have stem cell-like behaviour in vitro . These cells were isolated from both low grade and high grade primary brain tumours (astrocytoma, glioblastoma, ependymoma, medulloblastoma, anglioglioma) and represent only a small fraction of the total tumour cell population.

This subpopulation of tumour cells could be considered as cancer stem cells, because they share properties with normal neural stem cells and are necessary for maintaining tumour growth in vitro. The identification of the brain tumour stem cell has important implications for understanding the mechanisms of brain tumorigenesis. Because this cell represents only a small number of the total number of cells in a brain tumour, it suggests that therapy that spares this cell may explain tumour recurrence. Studies of a brain tumour stem cell will lead to further insight into the normal brain cell that is the target for brain tumorigenesis.

The second approach involves a study of normal neural stem cells, to attempt to understand key determinants of proliferation and self renewal in these cells. Dr. Dirks' research is focused on the study of the sonic hedgehog signalling pathway, because it has been found to be erturbed in primary human brain tumours (medulloblastomas), and because it has been shown to be critically important for normal brain development.

Preliminary studies in our laboratory suggest that different Shh pathway members play important and distinct roles in neural stem cell proliferation and self renewal. A better understanding of how this pathway functions in normal neural stem cells may help us to better understand brain tumour proliferation and self renewal.

External Funding

• National Cancer Institute of Canada - 2000 - 2003
• Jack Michael Baker Family

Publications

A detailed list of Dr. Dirks' publications is available on PubMed. »»

Intellectual Property

Treatment for Brain Cancer
Corporate Ventures