Ordered chaos: harnessing developmental pathways in tumor-induced lymphangiogenesis

Over the past decade, research investigating the development of the lymphatic vascular system has become a key focus within the fields of developmental biology and cancer biology. Critical discoveries relating to the specification of lymphatic endothelial cells and lymphatic morphogenesis during embryonic development have helped to identify novel molecular drivers of pathological lymphangiogenesis; that is, the sprouting of a new lymphatic vessel from, or the enlargement of, pre-existing lymphatic vessels. These pathways may also constitute potentially useful therapeutic targets, which may be exploited to restrict tumor spread via the lymphatic system. Here, we discuss the current knowledge of both developmental and tumor-induced lymphangiogenesis, and draw parallels between the two processes to describe the molecular pathways that are re-capitulated during the growth of tumor lymphatics, and which promote metastasis