Glioblastoma Multiformе Tumour Stem Cells as Potential Therapeutic Targets

The original concept of tumour stem cells (TSC) has been questioned ten years after TSCs in glioblastoma (GBM) had been described for the first time. Our understanding of cell heterogeneity in malignant brain tumours has become more complex. The improvements in our knowledge of tumour stem cells also impact on pre-clinical research and clinical practice. Chemoresistance is one of the key obstacles to success in treating malignant tumours; it results in tumour recurrence and metastatic spread. GBM relapse is almost universal, and its prognosis remains uncertain despite significant advances in treatment over the last decade. Tumour stem cells, glioblastoma stem cells (GSC) in particular, are highly resistant to chemotherapy, radiation therapy and immune recognition. GBM shows significant intratumoural phenotypic and molecular heterogeneity containing a population of tumour stem cells that contributes to the division of tumour cells supporting the resistance to treatment. TSCs are defined functionally by their ability for self-renewal and differentiation; they present a most diverse hierarchy of cells making up the tumour. The critical role of TSCs in glioblastoma pathogenesis makes the research into their molecular and phenotypic characteristics is a therapeutic priority.