Targeting Glioma Stem Cells: Path Leading to the Cure

Abstract

In the United States, 22020 new cases of cancer in central nervous system (CNS) are expected to occur in 2010 (CBTRUS 2010). Although the incidence of cancers in CNS is much lower than that of malignancies in other organs such as lung, breast and colorectal cancers, CNS cancers are the second lethal cancer for males younger than 40 years (Jemal et al. 2010). In addition, with the unconstraint growth, brain cancers can often involve eloquent area. As a result, the neurological and psychological deficits may severely damage the health-related quality of life (QOL) in patients with brain cancers. Improvement of QOL and the prognosis of brain cancers is the goal of both physicians and basic investigators. Glioblastoma multiforme (GBM) is the most frequent primary brain cancer, accounting for 17% of all primary tumours in CNS. In the past five decades, despite the advances in the fields of neurosurgery, radiotherapy and pharmaceutics, the prognosis of patients with GBM remains dismal, with a 5-year survival of only 9.8%(Stupp et al. 2009). The nature of extensive proliferation, diffuse infiltration and resistance to conventional treatments makes the chance to cure GBM slim. Exploration of mechanisms underlying therapeutic resistance of GBM and developing novel strategies against GBM are of urgent necessity. The emergence of brain tumour stem cell (BTSC) theory is a great breakthrough in the field of neuro-oncology. BTSC theory assumes that brain tumour is a hierarchy of cancer cells maintained by a small population of cells sharing characteristics of normal embryonic and somatic stem cells. BTSC theory is confirmed by the isolation of BTSCs from established brain tumour cell lines and freshly surgical samples. Accumulated evidence suggests that BTSCs are responsible for the initiation, progression, recurrence and treatment resistance. Therefore, BTSCs are promising therapeutic targets. In this chapter, we aim to summarize advances in BTSC biology with the focus on the treatment strategies against BTSCs.