Question: What are cancer stem cells and how do they affect brain tumour growth?
Answer:
Brain tumors have been long recognized to be heterogeneous (comprised of cells of many different shapes) and also identified by their expression of different protein markers. In the glioblastoma multiforme, the most common and aggressive primary brain tumor in adults, the diverse cellular heterogeneity is a noticeable feature by the very name of this tumour. Although the morphological (form and structure) heterogeneity of brain tumors is well recognized, it was not known until recently which of the diverse cells in the tumor initiate and maintain tumor growth. This is the similarity between brain tumors and stem cells and the central message: that not all brain tumor cells are created functionally equal.
Brain tumors have been recently shown to contain small numbers of cells that have stem cell properties and which maintain tumor growth. The tumour stem cells replenish themselves but also produce a much larger number of tumour cells that lose the ability to divide and maintain tumor growth. Therefore, these "cancer stem cells" are relatively rare but far more potent in fueling the growth of tumors. The fact that human leukemia and breast cancer also contain cancer stem cells supports that these cells are potentially important for many different types of cancers. Cancer stem cells may be a key to cancer cure and their identification has opened new doors for cancer research and new targets for therapy.
The knowledge about cancer stem cells predicts that treatments, which spare the tumor-maintaining cancer stem cells, will fail. So we need to create a therapy to target these cells. Despite these exciting advances, these findings are still in their initial stages and much research needs to be done before new cancer stem cell-killing treatment becomes possible for patients. We do not yet have a clear idea of what mechanisms actually drive cancer stem cell growth, and we don’t know which cell type in the brain causes these cells to arise. However, research is gaining momentum, so that hopefully more effective treatments will be developed in the not-too-distant future.
A special thank you to Dr. Peter Dirks for his time in informing us about this exciting area of research for this issue of Ask the Expert. Dr. Dirks joins us from the Division of Neurosurgery at the Hospital for Sick Children and the University of Toronto.
| |
| | | |
|
À 2003 Brain Tumour Foundation of Canada 1.800.265.5106
Charitable Registration #BN118816339RR0001 |