MORPHOGENESIS OF THE VASCULAR TREE

During morphogenesis oi the vascular tree, the massive outgrowth of pr imitive capillaries is followed by the development and the maturation of some capillary branches whereas others regress. The direct observat ion and the manipulation of in vivo models, including a series of rece nt knock-out experiments allow to delineate the mechanisms controlling this process, and to identify factors involved in the formation or a mature capillary, surrounded with a basal lamina and pericytes. Simult aneously new inhibitors have been purified from the study of tissues m icrometastases in which angio-genesis Is blocked. Upon anti-angiogenic therapy tumors stop growing and can also shrink dramatically. They wi ll eventually disappear following a conventional chemotherapeutic trea tment or several cycles of anti-angiogenic sever treatment since endot helial cells do not develop drug resistance.