Vascular endothelial growth factor

Vascular endothelial growth factor (VEGF), originally known as vascular permeability factor (VPF),[1] is a signal protein produced by cells that stimulates vasculogenesis and angiogenesis. It is part of the system that restores the oxygen supply to tissues when blood circulation is inadequate. Serum concentration of VEGF is high in bronchial asthma and diabetes mellitus.[2] VEGF's normal function is to create new blood vessels during embryonic development, new blood vessels after injury, muscle following exercise, and new vessels (collateral circulation) to bypass blocked vessels.

When VEGF is overexpressed, it can contribute to disease. Solid cancers cannot grow beyond a limited size without an adequate blood supply; cancers that can express VEGF are able to grow and metastasize. Overexpression of VEGF can cause vascular disease in the retina of the eye and other parts of the body. Drugs such as bevacizumab and ranibizumab can inhibit VEGF and control or slow those diseases.

VEGF is a sub-family of growth factors, to be specific, the platelet-derived growth factor family of cystine-knot growth factors. They are important signaling proteins involved in both vasculogenesis (the de novo formation of the embryonic circulatory system) and angiogenesis (the growth of blood vessels from pre-existing vasculature).

History

VEGF was first identified in guinea pigs, hamsters, and mice by Senger et al. in 1983.[1] It was purified and cloned by Ferrara and Henzel in 1989.[3] VEGF alternative splicing was discovered by Tischer et al. in 1991.[4] Between 1996 and 1997, Christinger and De Vos obtained the crystal structure of VEGF, first at 2.5 Å resolution and later at 1.9 Å.[5][6][7]

Fms-like tyrosine kinase-1 (flt-1) was shown to be a VEGF receptor by Ferrara et al. in 1992.[8] The kinase insert domain receptor (KDR) was shown to be a VEGF receptor by Terman et al. in 1992 as well.[9] In 1998, neuropilin 1 and neuropilin 2 were shown to act as VEGF receptors.[10]

Classification

Crystal structure of Vammin, a VEGF-F from a snake venom

The VEGF family comprises in mammals five members: VEGF-A, placenta growth factor (PGF), VEGF-B, VEGF-C and VEGF-D. The latter ones were discovered later than VEGF-A, and, before their discovery, VEGF-A was called just VEGF. A number of VEGF-related proteins encoded by viruses (VEGF-E) and in the venom of some snakes (VEGF-F) have also been discovered.

VEGF family
Type Function
VEGF-A
VEGF-B Embryonic angiogenesis (myocardial tissue, to be specific)[11]
VEGF-C Lymphangiogenesis
VEGF-D Needed for the development of lymphatic vasculature surrounding lung bronchioles
PlGF Important for Vasculogenesis, Also needed for angiogenesis during ischemia, inflammation, wound healing, and cancer.

Activity of VEGF-A, as its name implies, has been studied mostly on cells of the vascular endothelium, although it does have effects on a number of other cell types (e.g., stimulation monocyte/macrophage migration, neurons, cancer cells, kidney epithelial cells). In vitro, VEGF-A has been shown to stimulate endothelial cell mitogenesis and cell migration. VEGF-A is also a vasodilator and increases microvascular permeability and was originally referred to as vascular permeability factor.

Isoforms

Schematic representation of The different isoforms of human VEGF

There are multiple isoforms of VEGF-A that result from alternative splicing of mRNA from a single, 8-exon VEGFA gene. These are classified into two groups which are referred to according to their terminal exon (exon 8) splice site: the proximal splice site (denoted VEGFxxx) or distal splice site (VEGFxxxb). In addition, alternate splicing of exon 6 and 7 alters their heparin-binding affinity and amino acid number (in humans: VEGF121, VEGF121b, VEGF145, VEGF165, VEGF165b, VEGF189, VEGF206; the rodent orthologs of these proteins contain one fewer amino acids). These domains have important functional consequences for the VEGF splice variants, as the terminal (exon 8) splice site determines whether the proteins are pro-angiogenic (proximal splice site, expressed during angiogenesis) or anti-angiogenic (distal splice site, expressed in normal tissues). In addition, inclusion or exclusion of exons 6 and 7 mediate interactions with heparan sulfate proteoglycans (HSPGs) and neuropilin co-receptors on the cell surface, enhancing their ability to bind and activate the VEGF receptors (VEGFRs).[12] Recently, VEGF-C has been shown to be an important inducer of neurogenesis in the murine subventricular zone, without exerting angiogenic effects.[13]

Mechanism

Types of VEGF and their VEGF receptors.[14]

All members of the VEGF family stimulate cellular responses by binding to tyrosine kinase receptors (the VEGFRs) on the cell surface, causing them to dimerize and become activated through transphosphorylation, although to different sites, times, and extents. The VEGF receptors have an extracellular portion consisting of 7 immunoglobulin-like domains, a single transmembrane spanning region, and an intracellular portion containing a split tyrosine-kinase domain. VEGF-A binds to VEGFR-1 (Flt-1) and VEGFR-2 (KDR/Flk-1).[15] VEGFR-2 appears to mediate almost all of the known cellular responses to VEGF. The function of VEGFR-1 is less well-defined, although it is thought to modulate VEGFR-2 signaling.[16] Another function of VEGFR-1 may be to act as a dummy/decoy receptor, sequestering VEGF from VEGFR-2 binding (this appears to be particularly important during vasculogenesis in the embryo). VEGF-C and VEGF-D, but not VEGF-A, are ligands for a third receptor (VEGFR-3/Flt4), which mediates lymphangiogenesis. The receptor (VEGFR3) is the site of binding of main ligands (VEGFC and VEGFD), which mediates perpetual action and function of ligands on target cells. Vascular endothelial growth factor-C can stimulate lymphangiogenesis (via VEGFR3) and angiogenesis via VEGFR2. Vascular endothelial growth factor-R3 has been detected in lymphatic endothelial cells in CL of many species, cattle, buffalo and primate.[17]


Expression

VEGF-A production can be induced in cells that are not receiving enough oxygen.[15] When a cell is deficient in oxygen, it produces HIF, hypoxia-inducible factor, a transcription factor. HIF stimulates the release of VEGF-A, among other functions (including modulation of erythropoiesis). Circulating VEGF-A then binds to VEGF Receptors on endothelial cells, triggering a Tyrosine Kinase Pathway leading to angiogenesis. The expression of angiopoietin-2 in the absence of VEGF leads to endothelial cell death and vascular regression.[18] Conversely, a German study done in vivo found that VEGF concentrations actually decreased after a 25% reduction in oxygen intake for 30 minutes.[19] HIF1 alpha and HIF1 beta are constantly being produced but HIF1 alpha is highly O2 labile, so, in aerobic conditions, it is degraded. When the cell becomes hypoxic, HIF1 alpha persists and the HIF1alpha/beta complex stimulates VEGF release.

Clinical significance

VEGF in disease

VEGF-A 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 VEGF-A may be an early step in the process of metastasis, a step that is involved in the "angiogenic" switch. Although VEGF-A has been correlated with poor survival, its exact mechanism of action in the progression of tumors remains unclear.

VEGF-A is also released in rheumatoid arthritis in response to TNF-α, increasing endothelial permeability and swelling and also stimulating angiogenesis (formation of capillaries).

VEGF-A 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 VEGF-A, 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 that may threaten the sight.

VEGF-A 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 differs between the two diseases.

VEGF-D serum levels are significantly elevated in patients with angiosarcoma.[20]

Once released, VEGF-A 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 VEGF-A in glomeruli directly causes the glomerular hypertrophy that is associated with proteinuria.[21]

VEGF alterations can be predictive of early-onset pre-eclampsia.[22]

Anti-VEGF therapies

Anti-VEGF therapies are important in the treatment of certain cancers and in age-related macular degeneration. They can involve monoclonal antibodies such as bevacizumab (Avastin), antibody derivatives such as ranibizumab (Lucentis), or orally-available small molecules that inhibit the tyrosine kinases stimulated by VEGF: lapatinib (Tykerb/Tyverb), sunitinib (Sutent), sorafenib (Nexavar), axitinib, and pazopanib. (Some of these therapies target VEGF receptors rather than the VEGFs.) THC and cannabidiol both inhibit VEGF and slow Glioma growth.

Both antibody-based compounds are commercialized. The first three orally available compounds are commercialized, as well. The latter two (axitinib and pazopanib) are in clinical trials.

Bergers and Hanahan concluded in 2008 that anti-VEGF drugs can show therapeutic efficacy in mouse models of cancer and in an increasing number of human cancers. But, "the benefits are at best transitory and are followed by a restoration of tumour growth and progression."[23]

Later studies into the consequences of VEGF inhibitor use have shown that, although they can reduce the growth of primary tumours, VEGF inhibitors can concomitantly promote invasiveness and metastasis of tumours.[24][25]

AZ2171 (cediranib), a multi-targeted tyrosine kinase inhibitor has been shown to have anti-edema effects by reducing the permeability and aiding in vascular normalization.

A 2014 Cochrane Systematic Review studied the effectiveness of ranibizumab and pegaptanib, on patients suffering from macular edema caused by central retinal vein occlusion.[26] Participants on both treatment groups showed improvement in visual acuity measures and a reduction in macular edema symptoms over six months.[26]

Pre-clinical

VEGF is also inhibited by thiazolidinediones (used for diabetes mellitus type 2 and related disease), and this effect on granulosa cells gives the potential of thiazolidinediones to be used in ovarian hyperstimulation syndrome.[27]

Neovascular age-related macular degeneration

Ranibizumab, a monoclonal antibody fragment (Fab) derived from bevacizumab, has been developed by Genetech for intraocular use. In 2006, FDA approved the drug for the treatment of neovascular age-related macular degeneration (wet AMD). The drug had undergone three successful clinical trials by then.[28]

In the October 2006 issue of the New England Journal of Medicine (NEJM), Rosenfield, et al. reported that monthly intravitreal injection of ranibizumab led to significant increase in the level of mean visual acuity compared to that of sham injection. It was concluded from the two-year, phase III study that ranibizumab is very effective in the treatment of minimally classic (MC) or occult wet AMD (age-related macular degeneration) with low rates of ocular adverse effects.[29]

Another study published in the January 2009 issue of Ophthalmology provides the evidence for the efficacy of ranibizumab. Brown, et al. reported that monthly intravitreal injection of ranibizumab led to significant increase in the level of mean visual acuity compared to that of photodynamic therapy with verteporfin. It was concluded from the two year, phase III study that ranibizumab was superior to photodynamic therapy with verteporfin in the treatment of predominantly classic (PC) Wet AMD with low rates of ocular adverse effects.[30]

Although the efficacy of ranibizumab is well-supported by extensive clinical trials, the cost effectiveness of the drug is questioned. Since the drug merely stabilizes patient conditions, ranibizumab must be administered monthly. At a cost of $2,000.00 per injection, the cost to treat wet AMD patients in the United States is greater than $10.00 billion per year. Due to high cost, many ophthalmologists have turned to bevacizumab as the alternative intravitreal agent in the treatment of wet AMD. The drug costs $15.00 to 50.00 in the United States.

In 2007, Raftery, et al. reported in the British Journal of Ophthalmology that, unless ranibizumab is 2.5 times more effective the bevacizumab, ranibizumab is not cost-effective. It was concluded that the price of ranibizumab would have to be drastically reduced for the drug to be cost-effective.[31]

Off-label use of intravitreal bevacizumab has become a widespread treatment for neovascular age-related macular degeneration.[32] Although the drug is not FDA-approved for non-oncologic uses, some studies suggest that bevacizumab is effective in increasing visual acuity with low rates of ocular adverse effects. However, due to small sample size and lack of randomized control trial, the result is not conclusive.

In October 2006, the National Eye Institute (NEI) of the National Institutes of Health (NIH) announced that it would fund a comparative study trial of ranibizumab and bevacizumab to assess the relative efficacy and ocular adversity in treating wet AMD. This study, called the Comparison of Age-Related Macular Degeneration Treatment Trials (CATT Study), will enroll about 1,200 patients with newly diagnosed wet AMD, randomly assigning the patients to different treatment groups.

By May 2012, anti-VEGF treatment with Avastin has been accepted by Medicare, is quite reasonably priced, and effective. Lucentis has a similar but smaller molecular structure to Avastin, and is FDA-approved (2006) for treating MacD, yet remains more costly, as is the more recent (approved in 2011) EYLEA (aflibercept). Tests on these treatments are ongoing relative to the efficacy of one over another.

See also

References

  1. ↑ 1.0 1.1 Senger, DR; Galli, SJ; Dvorak, AM; Perruzzi, CA; Harvey, VS; Dvorak, HF (25 February 1983). "Tumor cells secrete a vascular permeability factor that promotes accumulation of ascites fluid.". Science (New York, N.Y.) 219 (4587): 983–5. doi:10.1126/science.6823562. PMID 6823562.
  2. ↑ Cooper, Mark; Dimitria Vranes; Sherif Youssef; Steven A. Stacker; Alison J. Cox; Bishoy Rizkalla; David J. Casley; Leon A. Bach; Darren J. Kelly; Richard E. Gilbert (November 1999). "Increased Renal Expression of Vascular Endothelial Growth Factor (VEGF) and Its Receptor VEGFR-2 in Experimental Diabetes". Diabetes 48 (11): 2229. doi:10.2337/diabetes.48.11.2229. Retrieved 6 November 2013.
  3. ↑ Ferrara, N; Henzel, WJ (15 June 1989). "Pituitary follicular cells secrete a novel heparin-binding growth factor specific for vascular endothelial cells.". Biochemical and biophysical research communications 161 (2): 851–8. doi:10.1016/0006-291x(89)92678-8. PMID 2735925.
  4. ↑ Tischer, E; Mitchell, R; Hartman, T; Silva, M; Gospodarowicz, D; Fiddes, JC; Abraham, JA (25 June 1991). "The human gene for vascular endothelial growth factor. Multiple protein forms are encoded through alternative exon splicing.". The Journal of biological chemistry 266 (18): 11947–54. PMID 1711045.
  5. ↑ Christinger, Hans W.; Muller, Yves A.; Berleau, Lea T.; Keyt, Bruce A.; Cunningham, Brian C.; Ferrara, Napoleone; de Vos, Abraham M. (November 1996). "Crystallization of the receptor binding domain of vascular endothelial growth factor". Proteins: Structure, Function, and Genetics 26 (3): 353–357. doi:10.1002/(SICI)1097-0134(199611)26:3<353::AID-PROT9>3.0.CO;2-E.
  6. ↑ Muller, YA; Li, B; Christinger, HW; Wells, JA; Cunningham, BC; de Vos, AM (8 July 1997). "Vascular endothelial growth factor: crystal structure and functional mapping of the kinase domain receptor binding site.". Proceedings of the National Academy of Sciences of the United States of America 94 (14): 7192–7. doi:10.1073/pnas.94.14.7192. PMID 9207067.
  7. ↑ Muller, YA; Christinger, HW; Keyt, BA; de Vos, AM (15 October 1997). "The crystal structure of vascular endothelial growth factor (VEGF) refined to 1.93 A resolution: multiple copy flexibility and receptor binding.". Structure (London, England: 1993) 5 (10): 1325–38. doi:10.1016/s0969-2126(97)00284-0. PMID 9351807.
  8. ↑ de Vries, C; Escobedo, JA; Ueno, H; Houck, K; Ferrara, N; Williams, LT (21 February 1992). "The fms-like tyrosine kinase, a receptor for vascular endothelial growth factor.". Science (New York, N.Y.) 255 (5047): 989–91. doi:10.1126/science.1312256. PMID 1312256.
  9. ↑ Terman, BI; Dougher-Vermazen, M; Carrion, ME; Dimitrov, D; Armellino, DC; Gospodarowicz, D; Böhlen, P (30 September 1992). "Identification of the KDR tyrosine kinase as a receptor for vascular endothelial cell growth factor.". Biochemical and biophysical research communications 187 (3): 1579–86. doi:10.1016/0006-291x(92)90483-2. PMID 1417831.
  10. ↑ Soker, S; Takashima, S; Miao, HQ; Neufeld, G; Klagsbrun, M (20 March 1998). "Neuropilin-1 is expressed by endothelial and tumor cells as an isoform-specific receptor for vascular endothelial growth factor.". Cell 92 (6): 735–45. doi:10.1016/s0092-8674(00)81402-6. PMID 9529250.
  11. ↑ Claesson-Welsh, L. (20 August 2008). "VEGF-B Taken to Our Hearts: Specific Effect of VEGF-B in Myocardial Ischemia". Arteriosclerosis, Thrombosis, and Vascular Biology 28 (9): 1575–1576. doi:10.1161/ATVBAHA.108.170878.
  12. ↑ A VEGF-A splice variant defective for heparan sulfate and neuropilin-1 binding shows attenuated signaling through VEGFR-2 doi:10.1007/s00018-006-6254-9
  13. ↑ Shin, Y. J., J. S. Choi, et al. (2010). "Induction of vascular endothelial growth factor receptor-3 mRNA in glial cells following focal cerebral ischemia in rats." J Neuroimmunol 229(1-2): 81-90.
  14. ↑ cancerpublications.com.
  15. ↑ 15.0 15.1 Holmes, Katherine; Roberts, Owain Ll; Thomas, Angharad M.; Cross, Michael J. (2007). "Vascular endothelial growth factor receptor-2: Structure, function, intracellular signalling and therapeutic inhibition". Cellular Signalling 19 (10): 2003–12. doi:10.1016/j.cellsig.2007.05.013. PMID 17658244.
  16. ↑ Karkkainen, M.J.; Petrova, T.V. (2000). "Vascular endothelial growth factor receptors in the regulation of angiogenesis and lymphangiogenesis". Oncogene 19 (49): 5598–5605. doi:10.1038/sj.onc.1203855. PMID 11114740.
  17. ↑ Ali, Ibne et al. (2013)"Expression and localization of locally produced growth factors regulating lymphangiogenesis during different stages of the estrous cycle in corpus luteum of buffalo" (Bubalus bubalis). Theriogenology http://www.sciencedirect.com/science/article/pii/S0093691X13004263
  18. ↑ Harmey, Judith (2004). VEGF and cancer. Georgetown, Tex: Landes Bioscience/Eurekah.com New York, N.Y. Kluwer Academic/Plenum Publishers. ISBN 0-306-47988-5.
  19. ↑ Oltmanns, K. M.; Gehring, H; Rudolf, S; Schultes, B; Hackenberg, C; Schweiger, U; Born, J; Fehm, H. L.; Peters, A (2006). "Acute hypoxia decreases plasma VEGF concentration in healthy humans". AJP: Endocrinology and Metabolism 290 (3): E434–9. doi:10.1152/ajpendo.00508.2004. PMID 16219663.
  20. ↑ Amo, Y.; Masuzawa, M.; Hamada, Y.; Katsuoka, K. (2004). "Serum concentrations of vascular endothelial growth factor-D in angiosarcoma patients". British Journal of Dermatology 150 (1): 160–1. doi:10.1111/j.1365-2133.2004.05751.x. PMID 14746640.
  21. ↑ Liu, E.; Morimoto, M.; Kitajima, S.; Koike, T.; Yu, Y.; Shiiki, H.; Nagata, M.; Watanabe, T.; Fan, J. (2007). "Increased Expression of Vascular Endothelial Growth Factor in Kidney Leads to Progressive Impairment of Glomerular Functions". Journal of the American Society of Nephrology 18 (7): 2094–104. doi:10.1681/ASN.2006010075. PMID 17554151.
  22. ↑ Andraweera, P. H.; Dekker, G. A.; Roberts, C. T. (2012). "The vascular endothelial growth factor family in adverse pregnancy outcomes". Human Reproduction Update 18 (4): 436–457. doi:10.1093/humupd/dms011. PMID 22495259.
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  24. ↑ Ebos, John; Christina R. Lee; William Cruz-Munoz; Georg A. Bjarnason; James G. Christensen; Robert S. Kerbel (March 2009). "Accelerated Metastasis after Short-Term Treatment with a Potent Inhibitor of Tumor Angiogenesis". Cancer Cell 15 (3): 232–239. doi:10.1016/j.ccr.2009.01.021. PMID 19249681. Retrieved 22 October 2012.
  25. ↑ Pàez-Ribes, Marta; Allen, Elizabeth; Hudock, James; Takeda, Takaaki; Okuyama, Hiroaki; Viñals, Francesc; Inoue, Masahiro; Bergers, Gabriele; Hanahan, Douglas; Casanovas, Oriol (March 2009). "Antiangiogenic Therapy Elicits Malignant Progression of Tumors to Increased Local Invasion and Distant Metastasis". Cancer Cell 15 (3): 220–231. doi:10.1016/j.ccr.2009.01.027. PMC 2874829. PMID 19249680. Retrieved 22 October 2012.
  26. ↑ 26.0 26.1 Braithwaite T, Nanji AA, Greenberg PB (2010). "Anti-vascular endothelial growth factor for macular edema secondary to central retinal vein occlusion". Cochrane Database Syst Rev 10: CD007325. doi:10.1002/14651858.CD007325.pub3. PMID 20927757.
  27. ↑ Shah DK, Menon KM, Cabrera LM, Vahratian A, Kavoussi SK, Lebovic DI (April 2010). "Thiazolidinediones decrease vascular endothelial growth factor (VEGF) production by human luteinized granulosa cells in vitro". Fertil. Steril. 93 (6): 2042–7. doi:10.1016/j.fertnstert.2009.02.059. PMC 2847675. PMID 19342033.
  28. ↑ "FDA Approves New Biologic Treatment for Wet Age-Related Macular Degeneration". FDA News & Events. June 30, 2006. Retrieved 17 April 2013.
  29. ↑ Brown, David M.; Michels, Mark; Kaiser, Peter K.; Heier, Jeffrey S.; Sy, Judy P.; Ianchulev, Tsontcho; Anchor Study, Group (2009). "Ranibizumab versus Verteporfin Photodynamic Therapy for Neovascular Age-Related Macular Degeneration: Two-Year Results of the ANCHOR Study". Ophthalmology 116 (1): 57–65. doi:10.1016/j.ophtha.2008.10.018. PMID 19118696.
  30. ↑ Rosenfeld, Philip J.; Brown, David M.; Heier, Jeffrey S.; Boyer, David S.; Kaiser, Peter K.; Chung, Carol Y.; Kim, Robert Y.; Marina Study, Group (2006). "Ranibizumab for Neovascular Age-Related Macular Degeneration". New England Journal of Medicine 355 (14): 1419–31. doi:10.1056/NEJMoa054481. PMID 17021318.
  31. ↑ Raftery, J.; Clegg, A.; Jones, J.; Tan, S. C.; Lotery, A. (2007). "Ranibizumab (Lucentis) versus bevacizumab (Avastin): modelling cost effectiveness". British Journal of Ophthalmology 91 (9): 1244–6. doi:10.1136/bjo.2007.116616. PMC 1954941. PMID 17431015.
  32. ↑ Patent Docs: Genentech Acts to Halt Off-label Use of Avastin® for Age-related Macular Degeneration

Further reading

  • Bengoetxea H, Argandoña EG, Lafuente JV (2008). "Effects of Visual Experience on Vascular Endothelial Growth Factor Expression during the Postnatal Development of the Rat Visual Cortex". Cerebral Cortex. 18 (7): 1630–39. doi:10.1093/cercor/bhm190. PMC 2430152. PMID 17986606.
  • Ferrara N, Gerber HP (2002). "The role of vascular endothelial growth factor in angiogenesis". Acta Haematol. 106 (4): 148–56. doi:10.1159/000046610. PMID 11815711.
  • Orpana A, Salven P (2003). "Angiogenic and lymphangiogenic molecules in hematological malignancies". Leuk. Lymphoma 43 (2): 219–24. doi:10.1080/10428190290005964. PMID 11999550.
  • Afuwape AO, Kiriakidis S, Paleolog EM (2003). "The role of the angiogenic molecule VEGF in the pathogenesis of rheumatoid arthritis". Histol. Histopathol. 17 (3): 961–72. PMID 12168808.
  • de Bont ES; Neefjes VM; Rosati S et al. (2003). "New vessel formation and aberrant VEGF/VEGFR signaling in acute leukemia: does it matter?". Leuk. Lymphoma 43 (10): 1901–9. doi:10.1080/1042819021000015844. PMID 12481883.
  • Ria R; Roccaro AM; Merchionne F et al. (2003). "Vascular endothelial growth factor and its receptors in multiple myeloma". Leukemia 17 (10): 1961–6. doi:10.1038/sj.leu.2403076. PMID 14513045.
  • Caldwell RB; Bartoli M; Behzadian MA et al. (2004). "Vascular endothelial growth factor and diabetic retinopathy: pathophysiological mechanisms and treatment perspectives". Diabetes Metab. Res. Rev. 19 (6): 442–55. doi:10.1002/dmrr.415. PMID 14648803.
  • Patan S (2004). "Vasculogenesis and angiogenesis". Cancer Treat. Res. Cancer Treatment and Research 117: 3–32. doi:10.1007/978-1-4419-8871-3_1. ISBN 978-1-4020-7704-3. PMID 15015550.
  • Machein MR, Plate KH (2004). "Role of VEGF in developmental angiogenesis and in tumor angiogenesis in the brain". Cancer Treat. Res. Cancer Treatment and Research 117: 191–218. doi:10.1007/978-1-4419-8871-3_13. ISBN 978-1-4020-7704-3. PMID 15015562.
  • Eremina V, Quaggin SE (2004). "The role of VEGF-A in glomerular development and function". Curr. Opin. Nephrol. Hypertens. 13 (1): 9–15. doi:10.1097/00041552-200401000-00002. PMID 15090854.
  • Storkebaum E, Lambrechts D, Carmeliet P (2004). "VEGF: once regarded as a specific angiogenic factor, now implicated in neuroprotection". BioEssays 26 (9): 943–54. doi:10.1002/bies.20092. PMID 15351965.
  • Ribatti D (2005). "The crucial role of vascular permeability factor/vascular endothelial growth factor in angiogenesis: a historical review". Br. J. Haematol. 128 (3): 303–9. doi:10.1111/j.1365-2141.2004.05291.x. PMID 15667531.
  • Loureiro RM, D'Amore PA (2005). "Transcriptional regulation of vascular endothelial growth factor in cancer". Cytokine Growth Factor Rev. 16 (1): 77–89. doi:10.1016/j.cytogfr.2005.01.005. PMID 15733833.
  • Herbst RS, Onn A, Sandler A (2005). "Angiogenesis and lung cancer: prognostic and therapeutic implications". J. Clin. Oncol. 23 (14): 3243–56. doi:10.1200/JCO.2005.18.853. PMID 15886312.
  • Pufe T; Kurz B; Petersen W et al. (2006). "The influence of biomechanical parameters on the expression of VEGF and endostatin in the bone and joint system". Ann. Anat. 187 (5–6): 461–72. doi:10.1016/j.aanat.2005.06.008. PMID 16320826.
  • Tong JP, Yao YF (2006). "Contribution of VEGF and PEDF to choroidal angiogenesis: a need for balanced expressions". Clin. Biochem. 39 (3): 267–76. doi:10.1016/j.clinbiochem.2005.11.013. PMID 16409998.
  • Lambrechts D, Carmeliet P (2007). "VEGF at the neurovascular interface: therapeutic implications for motor neuron disease". Biochim. Biophys. Acta 1762 (11–12): 1109–21. doi:10.1016/j.bbadis.2006.04.005. PMID 16784838.
  • Matsumoto T, Mugishima H (2006). "Signal transduction via vascular endothelial growth factor (VEGF) receptors and their roles in atherogenesis". J. Atheroscler. Thromb. 13 (3): 130–5. doi:10.5551/jat.13.130. PMID 16835467.
  • Bogaert E, Van Damme P, Van Den Bosch L, Robberecht W (2006). "Vascular endothelial growth factor in amyotrophic lateral sclerosis and other neurodegenerative diseases". Muscle Nerve 34 (4): 391–405. doi:10.1002/mus.20609. PMID 16856151.
  • Mercurio AM, Lipscomb EA, Bachelder RE (2006). "Non-angiogenic functions of VEGF in breast cancer". Journal of Mammary Gland Biology and Neoplasia 10 (4): 283–90. doi:10.1007/s10911-006-9001-9. PMID 16924371.
  • Makinde T, Murphy RF, Agrawal DK (2007). "Immunomodulatory role of vascular endothelial growth factor and angiopoietin-1 in airway remodeling". Curr. Mol. Med. 6 (8): 831–41. doi:10.2174/156652406779010795. PMID 17168735.
  • Rini BI, Rathmell WK (2007). "Biological aspects and binding strategies of vascular endothelial growth factor in renal cell carcinoma". Clin. Cancer Res. 13 (2 Pt 2): 741s–746s. doi:10.1158/1078-0432.CCR-06-2110. PMID 17255303.
  • Rodgers LS, Lalani S, Hardy KM, Xiang X, Broka D, Antin PB, Camenisch TD. (2006). "Depolymerized hyaluronan induces vascular endothelial growth factor, a negative regulator of developmental epithelial-to-mesenchymal transformation". Circ Res. 99 (6): 583–9. doi:10.1161/01.RES.0000242561.95978.43. PMID 16931798.
  • Qaum T, Xu Q, Joussen AM, et al.VEGF-initiated blood-retinal barrier breakdown in early diabetes. Invest Ophthalmol Vis Sci. 2001;42:2408–2413.

External links