Editorial [Hot topic: Angiogenesis and Lymphangiogenesis in Common Diseases (Guest Editor: Y. Cao)]

Thirty-eight years ago when Judah Folkman proposed the first hypothesis of antiangiogenic cancer therapy, he and others had not fully appreciated the impact of pathological angiogenesis on contribution to the onset, development, and progression of the most common and severe human diseases. Folkman's original hypothesis, however, has revolutionized our thinking of development of novel therapeutic approaches for the treatment of multiple human disorders by targeting the pathological angiogenesis. Today, we know that nearly 100 human diseases including cardiovascular diseases, cancer, metastasis, diabetic complications, age-related macular degeneration, obesity, and chronic inflammation are involved in malformation or dysfunction of the vasculature. Angiogenesis research has become one of the most attractive, exciting, and promising areas in biomedicine for the development of new drugs against most common and lethal human diseases such as cancer and cardiovascular diseases. At the time when this was being composed (October), there were 4, 074 papers under the topic of angiogenesis published in 2008. In 2004, two anti-VEGF drugs, bevacizumab (avastin) and pegaptanib (macugen) had been approved for the treatment of metastatic colorectal cancer and age-related macular degeneration, respectively. These initial successes of antiangiogenic therapy in the clinic laid important milestones, which led to the approval of several other drugs mainly targeting the VEGF-mediated signaling pathways. For example, sunitinib and sorafenib were subsequently approved by the USA FDA for the treatment of various cancers, and lucentis was approved for the treatment of macular degeneration. Currently, there are approximately 40 different antiangiogenic agents are in phase III trials and hundreds are in phase II or phase I trials for the treatment of various cancers. The new generation of antiangiogenic agents seems to have broader targets by blocking multiple pathways as compared with the monospecific drugs such as bevacizumab. In contrast to the success of antiangiogenic therapy, delivery of proangiogenic agents to the ischemic myocardium or skeletal muscles in clinical patients has not been approved to be a valid approach for the treatment of myocardiac infarction or ischemic legs. Although the underlying mechanism of these clinical failures is not fully understood, these clinical findings suggest that promotion and remodeling of arteriogenesis or collaterogenesis involve complex interplay between various angiogenic and proangiogenic factors. Thus, combination therapy consisting of various proangiogenic and arteriogenic factors warrants further clinical evaluation. The aim of this special issue is to highlight the impact of angiogenesis and lymphangiogenesis on clinical development of novel therapeutic approaches. We are very grateful to many experts who have helped us to contribute review articles in their expertise to this issue. We hope that these review articles could further stimulate the excitement of angiogenesis research and could pave new pathways for young scientists who are pursuing their research careers in this field. It has been estimated that approximately 15, 000, 000 patients globally will benefit from antiangiogenic therapy by the end of 2009. Antiangiogenic agents have become the key composition of the front-line therapy for various solid cancers. Anti-VEGF agents have also considered as very effective drugs for the treatment of age-related macular been degeneration. From now, one can only imagine that dreams of miracle drugs for many patients will probably become true within the next 10 years. We thank Dr. Judah Folkman and many other experts who have paved this avenue for all of us to experience this angiogenic “revolution”.