Figure 1

Mechanisms of tumor vascularization. The different mechanisms of tumor vascularization are depicted in the figure. These include: (A) sprouting angiogenesis: sprouting of pre-existing brain capillaries through proliferation and migration of local ECs; (B) vasculogenic mimicry: tumor cell-constituted, matrix-embedded fluid-conducting meshwork; (C) vascular co-option: tumor cells grow along pre-existing blood vessels; (D) vascular intussusception: internal division of the preexisting capillary plexus; (E) bone marrow-derived vasculogenesis: recruitment of circulating endothelial precursors (EPCs) to form new vessels; (F) cancer stem-like cell-derived vasculogenesis: transdifferentiation of CSCs into ECs to form new vessels.