Abstract

The presence of cancer stem cells in brain tumors has been suggested in the recent years, extrapolating from other types of malignancies. The actual debate centers on the possibility that this small group of cells or a single cell can initiate and maintain such an aggressive malignancy status. Cancer stem cells are a major theme for aggressive brain tumors, their extensive study offering potential biomarkers for identification of therapy targets based on abnormal and connected signaling pathways. This chapter presents the phenomenology of cancer stem cells in their microenvironment, in its astonishing complexity. Identification markers, pathologic signaling profiles and cross-talk, microenvironment interactions and novel therapies targeting cancer stem cells are discussed. Continuous studies are researching genetic and epigenetic modifications associated with malignant evolution in glioma cancer stem cells. From the complex entangled signaling pathways presented, one must extract only the important molecules involved in oncogenesis onset and propagation, putting aside the coincidentally modified molecules that can be misleading. After removing the “smoke screen” of oncogenic irrelevant, but modified molecules, there remain the true therapy targets, to address by specific therapies in a combined manner to overcome the adapting processes governed by signaling pathway cross-talk.