Glioblastoma Multiform (GBM) is known as an aggressive brain cancer for which there is no cure. But as researchers work to understand this disease, they discover that GBM may an ideal teacher to help us develop safe and effective stem cell therapeutics.
In recent studies published in the March 2009 issue of Oncogene (Picirillo et al., 2009, Oncogene 28, 1807–1811) revealed that there are cellular variations in a typical primary human glioblastoma. Of particular interest is the GBM cancer stem-like cell population in the periphery of the tumor (pGBM), which demonstrates properties similar to multipotent stem cells. Most surprisingly, pGBM cells are not tumorigenic, in that they are no longer able to produce tumors when transplanted into a naïve mouse.
A dangerous idea that comes to mind is whether pGBM cells can be used as a stem cell therapeutic to promote tissue repair in the central nervous system. As one of the cell populations that make up the GBM, pGBM cells would likely to have inherited the long evolved mechanism of the GBM to evade the host immune system. In the light of current risks associated with stem cell therapeutics including rejection and cancer risks, pGBM cells may possess the necessary non-tumorigenic and immune evasive properties to be a low risk stem cell alternative.
Aesthetically, using pGBM cells as a stem cell therapeutic may not be very appealing. Afterall, pGBM cells are derived from one of the most aggressive cancers in the human central nervous system. Since cancer progression often involves complex interactions with the host, there is a remote possibility that pGBM can be tumorigenic particularly in a host environment weakened by neurotrauma and neurodegenerative disease. Until we learn more about the behaviour of pGBM cells, perhaps a more acceptable approach at present may be to use pGBM cells as a tool to unlock the secrets for safe and effective stem cell therapeutics.