VEGFxxx has been implicated with poor prognosis in breast cancer. Numerous studies show a decreased overall survival and disease-free survival in those tumors overexpressing VEGF. The overexpression of VEGFxxx may be an early step in the process of metastasis, a step that is involved in the "angiogenic" switch. Although VEGFxxx has been correlated with poor survival, its exact mechanism of action in the progression of tumors remains unclear.
VEGFxxx is also released in rheumatoid arthritis in response to TNF-α, increasing endothelial permeability and swelling and also stimulating angiogenesis (formation of capillaries).
VEGFxxx is also important in diabetic retinopathy (DR). The microcirculatory problems in the retina of people with diabetes can cause retinal ischaemia, which results in the release of VEGFxxx, and a switch in the balance of pro-angiogenic VEGFxxx isoforms over the normally expressed VEGFxxxb isoforms. VEGFxxx may then cause the creation of new blood vessels in the retina and elsewhere in the eye, heralding changes which may threaten the sight.
VEGFxxx plays a role in the disease pathology of the wet form age-related macular degeneration (AMD), which is the leading cause of blindness for the elderly of the industrialized world. The vascular pathology of AMD shares certain similarities with diabetic retinopathy, although the cause of disease and the typical source of neovascularization differes between the two diseases.
VEGF-D serum levels are significantly elevated in patients with angiosarcoma.
Once released, VEGFxxx may elicit several responses. It may cause a cell to survive, move, or further differentiate. Hence, VEGF is a potential target for the treatment of cancer. The first anti-VEGF drug, a monoclonal antibody named bevacizumab, was approved in 2004. Approximately 10-15% of patients benefit from bevacizumab therapy; however, biomarkers for bevacizumab efficacy are not yet known.
Current studies show that VEGFs are not the only promoters of angiogenesis. In particular FGF2 and HGF are potent angiogenic factors.
Patients suffering from pulmonary emphysema have been found to have decreased levels of VEGF in the pulmonary arteries.
In the kidney, increased expression of VEGFxxx in glomeruli directly causes the glomerular hypertrophy that is associated with proteinuria.
Further Reading
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"Vascular endothelial growth factor"
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