CD133 as a marker for regulation and potential for targeted therapies in glioblastoma multiforme.

The CD133 epitope has been identified as a tumor marker for the purification of a subpopulation of glioblastoma multiforme (GBM) cells demonstrating cancer stem cell phenotypes. Isolated tumorsphere-forming CD133(+) GBM cells demonstrated heightened in vitro proliferation, self-renewal, and invasive capacity. Orthotopic transplantation of CD133(+) cells led to the formation of heterogeneous tumors that were phenocopies of the original patient tumor. In this article, the authors discuss the complex regulation of CD133 expression in gliomas, its role in tumorigenesis, and its potential as a marker for targeted and personalized therapeutic intervention.