Early start for new tumor vessels

Small tumors need blood vessels for growth but it is not clear whether aggregates of malignant cells can induce vascularization or whether these cells grow by co-opting preexisting vessels. In March 15 Journal of Clinical Investigation Peter Vajkoczy and colleagues from University of Heidelberg, Germany, show that new vessels occur as a continuing process of growth and remodeling, starting very early in tumor progression (J Clin Invest 2002, 109:777-785).

Vajkoczy et al. used intravital epifluorescence microscopy and confocal microscopy to visualize C6 microglioma vascularization and tumor cell behavior. They found that multicellular aggregates (< 1 mm³) initiate vascular growth by angiogenic sprouting via the simultaneous expression of VEGFR-2 and Ang-2 by host and tumor endothelium. In addition, they provide evidence that host blood vessels are not co-opted by the tumor cells but rather are used as trails for glioma cell invasion of the adjacent host...