Angiogenesis

About: Angiogenesis is a research topic. Over the lifetime, 58248 publications have been published within this topic receiving 3290129 citations. The topic is also known as: blood vessel formation from pre-existing blood vessels & GO:0001525.

Clinical importance of the determination of tumor angiogenesis in breast carcinoma: much more than a new prognostic tool.

Abstract: PURPOSETo review prognostic and therapeutic applications of angiogenesis research in breast carcinoma.METHODSWe reviewed the (1) biologic role of angiogenesis, particularly in transformation, progression, and metastasis of breast cancer; (2) methods to detect angiogenic activity in human pathology; (3) clinical studies relating clinical outcome of patients with breast cancer to the assessment of angiogenesis; (4) predictive value of angiogenesis for response to anticancer therapies; and (5) pharmacologic characteristics of current antiangiogenic drugs.RESULTSThere is mounting evidence that angiogenesis plays a relevant role in the biologic aggressiveness of breast cancer. Using either immunohistochemical or biochemical methods, several studies have shown a worse prognosis for those patients with tumors with high angiogenic activity. In some studies angiogenesis has an independent prognostic value. The most promising angiogenic inhibitors are under early-phase clinical evaluation in patients with tumors re...

Dominant-Negative Inhibition of Flk-1 Suppresses the Growth of Many Tumor Types in Vivo

Abstract: Angiogenesis, the sprouting of new blood vessels from existing vessels, occurs in many physiological and pathological processes, including embryonic development, wound healing, and tumor growth. It is required for tumor growth because new blood vessel formation is necessary for tumors to expand beyond a minimum volume. Several growth factor receptor tyrosine kinases have been implicated in angiogenesis, including receptors for epidermal, fibroblast, and platelet-derived growth factors, as well as the receptors Flk-1/KDR, Flt-1, Tek/Tie-2, and Tie-1. Endothelial cells in the vessels of tumors express Flk-1/KDR, a receptor for vascular endothelial growth factor. Flk-1 was previously shown to play a role in angiogenesis and tumor formation of s.c. xenografts of C6 glioma cells using dominant-negative methodology. We now demonstrate that Flk-1 seems to be generally involved in the growth of a wide range of solid tumors, including mammary, ovarian, and lung carcinoma, as well as glioblastoma. Furthermore, survival times in rats bearing intracerebral tumors were prolonged using the same dominant-negative methodology. The involvement of Flk-1 in a variety of tumor types suggests an important role for Flk-1 in tumor angiogenesis.

Anti-angiogenesis for cancer revisited: Is there a role for combinations with immunotherapy?

Abstract: Angiogenesis is defined as the formation of new blood vessels from preexisting vessels and has been characterized as an essential process for tumor cell proliferation and viability. This has led to the development of pharmacological agents for anti-angiogenesis to disrupt the vascular supply and starve tumor of nutrients and oxygen, primarily through blockade of VEGF/VEGFR signaling. This effort has resulted in 11 anti-VEGF drugs approved for certain advanced cancers, alone or in combination with chemotherapy or other targeted therapies. But this success had only limited impact on overall survival of cancer patients and rarely resulted in durable responses. Given the recent success of immunotherapies, combinations of anti-angiogenics with immune checkpoint blockers have become an attractive strategy. However, implementing such combinations will require a better mechanistic understanding of their interaction. Due to overexpression of pro-angiogenic factors in tumors, their vasculature is often tortuous and disorganized, with excessively branched leaky vessels. This enhances vascular permeability, which in turn is associated with high interstitial fluid pressure, and a reduction in blood perfusion and oxygenation. Judicious dosing of anti-angiogenic treatment can transiently normalize the tumor vasculature by decreasing vascular permeability and improving tumor perfusion and blood flow, and synergize with immunotherapy in this time window. However, anti-angiogenics may also excessively prune tumor vessels in a dose and time-dependent manner, which induces hypoxia and immunosuppression, including increased expression of the immune checkpoint programmed death receptor ligand (PD-L1). This review focuses on revisiting the concept of anti-angiogenesis in combination with immunotherapy as a strategy for cancer treatment.