GLI1 finds a new role in cancer stem cell biology

» Goel et al. have identified a novel cascade downstream of the VEGF receptor Neuropilin-2 (NRP2) regulating the biology of tumour initiating cells. « with the ability to self-renew and differentiate into the heterogeneous populations of the original tumour (Magee et al, 2012; Sampieri & Fodde, 2012; Zhou et al, 2009). This constitutes the cancer stem cell hypothesis, which is gaining significant attention because it may explain resistance to therapy and tumour recurrence (Zhou et al, 2009). Tumour initiating cells were first described in leukaemias in the early 1990s andmore recently in an increasing number of solid tumours (Bonnet et al, 1990), especially the poorly differentiated ones (Sampieri & Fodde, 2012). Tumour initiating cells can originate from the transformation of normal tissue stem cells or derive from an existing cancer cell population. In certain tumours, this cell population is present in specific niches that make them more resistant to treatment to therapy (Magee et al, 2012; Zhou et al, 2009). Although much work is still needed to identify and characterize the biology of tumour initiating cells, efforts are now being directed towards designing therapeutic strategies to target this cellular compartment. The characterization of the specific signalling pathways controlling the biology of these cells is thus needed to help design