Growth regulation of nervous system tumours: Models for assessment of angiogenesis in brain tumours

Abstract

The metabolic demand of rapidly proliferating tumour cells is reliant on an adequate blood supply that allows the continual delivery of oxygen, nutrients and growth factors. The growth and progression of tumours is significantly reduced in the absence of neovascularization and often increased abnormal neoangiogenesis correlates with the increased malignancy and poor prognosis in many tumours. By far, the most studied and understood mechanism of blood vessel formation is via angiogenesis, a process that initiates the sprouting and elongation of existing vessels into the tumour. However, more recent concepts suggest that in large tumours, the process of vasculogenesis, whereby bone marrow derived progenitor cells (BMDPCs) are recruited to the tumour and differentiate into ECs and other vascular cell types, is a more important mechanism of generating de novo vessels. The mechanisms underlying both processes are poorly understood and the redundancy between signalling pathways involved leads to complications in elucidating the control mechanisms involved. Using various experimental techniques to investigate the processes of tumour neovascularization is an evolving field, one which in this chapter we try to summarize and provide an overview of both the traditional and more novel experimental techniques used to study angiogenesis. © 2013 Springer Science+Business Media New York.