Lymphangiogenesis In Health And Disease - An Overview

The blood and lymphatic vascular networks combine to facilitate immune function and maintain tissue fluid homeostasis in the body. Although these two systems share many common structural and molecular features, recent advances in our understanding of the molecular control of the lymphatics have identified distinct molecular pathways responsible for the formation and function of the lymphatic network. These advances have led to the characterisation of lymphatic-specific markers and growth factors which control lymphatic development and function. Insights gained from in vitro and in vivo studies over the past decade have highlighted the importance of the lymphatic system in human diseases such as lymphedema, inflammatory disorders and cancer. The lymphatic vasculature is an important route for the metastatic spread of tumor cells, and recent studies based on animal models of cancer indicated that lymphangiogenic growth factors, secreted by tumor cells or components of the tumor stroma, can induce formation of new lymphatic vessels in the vicinity of a primary tumor. These studies, as well as clinicopathological data, suggest that this process of tumor lymphangiogenesis can be associated with enhanced metastastic spread - hence tumor lymphangiogenesis is being explored as a therapeutic target for restricting the metastatic spread of cancer.