Yi Lu
University of Tennessee Health Science Center United States of America
Vascular endothelial growth factor (VEGF) is a mitogen that plays a crucial role in angiogenesis and lymphangiogenesis. It is involved in tumor survival through inducing tumor angiogenesis and by increasing chemoresistance through autocrine signaling. Because of its importance in tumor formation and survival, several medications have been developed to inhibit VEGF and reduce blood vessel formation in cancer. Although these medications have proven to be effective for late-stage and metastatic cancers, they have been shown to cause side effects such as hypertension, artery clots, complications in wound healing, and, more rarely, gastrointestinal perforation and fistulas. Current research in using anti-VEGF medication as a part of cancer treatments is focusing on elucidating the mechanisms of tumor resistance to VEGF medication, developing predictive biomarkers that assess whether a patient will respond to VEGF therapy and creating novel treatments and techniques that increase the efficacy of antiangiogenic medication. This chapter aims to review the role of VEGF in tumor angiogenesis and metastasis, the structure and function of VEGF and its receptors, and VEGF’s role in cancer are discussed. Furthermore, tumor therapies targeting VEGF along with their side effects are presented and, finally, new directions in anti-VEGF therapy are considered along with the challenges.
Part of the book: Physiologic and Pathologic Angiogenesis
The tumor microenvironment consists of multiple types of cells, including endothelial cells, pericytes, neutrophil macrophage mast cells, lymphatic cells, basement membrane extracellular matrix, as well as fibroblasts. Fibroblasts populations found in cancers, also known as cancer-associated fibroblasts, have been implicated in the initiation, progression, and metastasis of tumors. This chapter will focus on the roles of cancer-associated fibroblasts in the progression of cancer and the studies of use of cancer-associated fibroblasts as a therapeutic target for cancer intervention.
Part of the book: Tumor Microenvironment
Metabolism is essential for a cell to obtain energy for its growth and development. In tumors, the rapid rate of cell proliferation leads to an increased demand for energy. Because nutrients in the tumor microenvironment are scarce, there is great competition between tumor cells and healthy cells to obtain them. Because of this, tumor cells undergo adaptations to outcompete healthy cells for nutrients. These adaptations cause characteristic changes to the tumor microenvironment, which in turn, causes changes to immune cells in the tumor tissue. These changes help the tumor evade immune detection and cause tumor growth and metastasis. This review will analyze the changes that take place in the tumor microenvironment, the impact they have on immune cells, and how this contributes to cancer progression.
Part of the book: Tumor Microenvironment