Essentials facts about VEGF-C in lymphology

By jeltsch on Fri, 05/05/2017 - 21:50

Dr. Michael Jeltsch, adjunct professor, University of Helsinki & Wihuri Research Institute, Finland, michael@jeltsch.org

Vascular endothelial growth factor C (VEGF-C) is essential for the development and growth of the lymphatic vasculature. Together with VEGF-D, it forms the lymphatic subgroup within the VEGF family of growth factors, whose other members (PlGF, VEGF/VEGF-A, VEGF-B) are primarily responsible for the growth and function of blood vessels.

VEGF-C was discovered as a ligand of the tyrosine kinase receptor VEGFR-3 (1) and its specific effect on lymph vessels was first described in 1997 (2,3). About one-third of hereditary lymphedema cases in humans result from mutations in genes involved in VEGF-C signaling (4). The complete absence of VEGF-C leads to death during embryogenesis (5). Likely for this reason, clinical cases of hereditary lymphedema are characterised by a partial inactivation of the signal transduction. VEGFR-3 (6) is affected in most cases, but mutations of the hereditary lymphedema are described or suspected for all components of the VEGF-C signal transduction described below. z.T. As part of a multifactorial inheritance.

Regulation of VEGF-C activity
The functional differences between the angiogenic and lymphangiogenic VEGFs are reflected in their structure. In contrast to the angiogenic VEGFs, which are active immediately after secretion, VEGF-C is produced as an inactive protein and is only activated by two enzymatic cleavages (7). The first enzymatic section is constitutive. The resulting pro-VEGF-C can bind the VEGFR-3, but not yet activate it. Only with the second cut VEGF-C becomes active. ADAMTS3 (A Disintegrin and Metalloproteinase with Thrombospondin motifs 3) was identified as responsible protease (8). To enable ADAMTS3 to activate VEGF-C, the CCBE1 (Collagen And Calcium binding EGF domains 1) protein is necessary. CCBE1 fulfills two functions: its C-terminal domain activates ADAMTS3 (9), while its N-terminal domain immobilizes VEGF-C on the lymphatic endothelial cell surface and thus assures efficient activation by the similarly cell surface-associated ADAMTS (10).
Unlike the VEGF-A production, which is triggered by hypoxia, the triggers for VEGF-C production are less well known. It has been hypothesized and appears plausible that larger caliber blood vessels are responsible for establishing tissue drainiage via VEGF-C secretion. Likley, interstitial pressure plays a role in both embryonic and adult lymphangiogenesis (11).

VEGF-C as a pharmacological target
The important role of the VEGF-C/VEGFR-3 in angiogenic signaling has established VEGF-C as a drug target in antiangiogenic tumor therapy (12). The active role of VEGF-C in lymphogenic metastasis and the therapeutic efficacy of a VEGF-C/VEGFR-3 blockade has been demonstrated in preclinical studies (13,14). However, due to significant differences between mice and men in the VEGF-C/VEGFR-3 axis (15/16), it remains unclear, how relevant these studies are for tumors in humans.
Newer studies show convincingly, that lymph node infiltration might rather be a proxy for metastasis potential than represent a stage of distant organ metastsis itself (17).

The design of the only completed clinical trial (Phase 1), in which VEGF-C signals have been blocked with antibodies, unfortunately does not allow conclusions as to whether a VEGFR-3 blockade inhibits lymphatic metastasis (monotherapy of colorectal carcinomas, n = 21, 18). Intermediate results from an ongoing study in which VEGF-A and VEGF-C signaling pathways are simultaneously blocked indicate that a combination therapy may be helpful (19). Compared with the anti-VEGF-A standard therapy (20), patients report increased edema symptoms (18).

Lymphangiogenesis stimulation as edema therapy?
Primary lymphoedema, whose molecular cause is a reduced VEGF-C signal, has been successfully treated by VEGF-C administration in preclinical studies in mice (21). In a clinical study, where the aim is to treat secondary lymphedema after a breast cancer surgery, VEGF-C is administered in conjunction with a lymph node transplant (brand name Lymfactin ™). This study by Herantis Pharma has treated almost a dozen patients since the end of 2014, but has not published any results yet (22,23).

The unforeseen effect of ketoprofen on lymphedema (24) is due to the inhibition of leukotriene A4 hydrolase. The drug Bestatin/Ubenimex does not inhibit prostaglandin synthesis to the same extent as ketoprofen and therefore, its side effects are less pronounced and it is used for the currently ongoing clinical studies (25). It has been proposed that its effect might be partly due to an indirect effect on VEGF-C production.

German abstract ("Was man in der Lymphologie über VEGF-C wissen sollte"): http://jeltsch.org/Abstrakt-BadSoden2017

Bibliography

  1. Joukov, V. et al. A novel vascular endothelial growth factor, VEGF-C, is a ligand for the Flt4 (VEGFR-3) and KDR (VEGFR-2) receptor tyrosine kinases. EMBO J 15, 290–298 (1996). http://www.ncbi.nlm.nih.gov/pmc/articles/PMC449944/
  2. Jeltsch, M. et al. Hyperplasia of Lymphatic Vessels in VEGF-C Transgenic Mice. Science 276, 1423–1425 (1997). http://dx.doi.org/10.1126/science.276.5317.1423
  3. Oh, S.-J. et al. VEGF and VEGF-C: Specific Induction of Angiogenesis and Lymphangiogenesis in the Differentiated Avian Chorioallantoic Membrane. Developmental Biology 188, 96–109 (1997). http://dx.doi.org/10.1006/dbio.1997.8639
  4. Mattonet, K., Wilting, J. & Jeltsch, M. Die genetischen Ursachen des primären Lymphödems. in Erkrankungen des Lymphgefäßsystems (eds. Weissleder, H. & Schuchhardt, C.) 210–229 (Viavital Verlag, 2015).
  5. Karkkainen, M. J. et al. Vascular endothelial growth factor C is required for sprouting of the first lymphatic vessels from embryonic veins. Nat Immunol 5, 74–80 (2003). http://dx.doi.org/10.1038/ni1013
  6. Karkkainen, M. J. et al. Missense mutations interfere with VEGFR-3 signalling in primary lymphoedema. Nature Genetics 25, 153–159 (2000). https://dx.doi.org/10.1038/75997
  7. Joukov, V. et al. Proteolytic processing regulates receptor specificity and activity of VEGF-C. The EMBO Journal 16, 3898–3911 (1997). http://dx.doi.org/10.1093/emboj/16.13.3898
  8. Jeltsch, M. et al. CCBE1 Enhances Lymphangiogenesis via A Disintegrin and Metalloprotease With Thrombospondin Motifs-3–Mediated Vascular Endothelial Growth Factor-C Activation. Circulation 129, 1962–1971 (2014). http://dx.doi.org/10.1161/CIRCULATIONAHA.113.002779
  9. Roukens, M. G. et al. Functional Dissection of the CCBE1 Protein A Crucial Requirement for the Collagen Repeat Domain. Circ Res 116, 1660–1669 (2015). https://dx.doi.org/10.1161/CIRCRESAHA.116.304949
  10. Jha, S. K. et al. Efficient activation of the lymphangiogenic growth factor VEGF-C requires the C-terminal domain of VEGF-C and the N-terminal domain of CCBE1. Sci Rep 7, 4916 (2017). https://dx.doi.org/10.1038/s41598-017-04982-1
  11. Planas-Paz, L. et al. Mechanoinduction of lymph vessel expansion. EMBO J 31, 788–804 (2012). http://dx.doi.org/10.1038/emboj.2011.456
  12. Tammela, T. et al. Blocking VEGFR-3 suppresses angiogenic sprouting and vascular network formation. Nature 454, 656–660 (2008). http://dx.doi.org/10.1038/nature07083
  13. Mandriota, S. J. et al. Vascular endothelial growth factor-C-mediated lymphangiogenesis promotes tumour metastasis. EMBO J 20, 672–682 (2001). http://dx.doi.org/10.1093/emboj/20.4.672
  14. Karpanen, T. et al. Vascular Endothelial Growth Factor C Promotes Tumor Lymphangiogenesis and Intralymphatic Tumor Growth. Cancer Res 61, 1786–1790 (2001). http://cancerres.aacrjournals.org/content/61/5/1786
  15. Hughes, D. C. Alternative Splicing of the Human VEGFGR-3/FLT4 Gene as a Consequence of an Integrated Human Endogenous Retrovirus. J Mol Evol 53, 77–79 (2001). https://dx.doi.org/10.1007/s002390010195
  16. Baldwin, M. E. et al. The Specificity of Receptor Binding by Vascular Endothelial Growth Factor-D Is Different in Mouse and Man. J. Biol. Chem. 276, 19166–19171 (2001). https://dx.doi.org/10.1074/jbc.M100097200
  17. Naxerova, K. et al. Origins of lymphatic and distant metastases in human colorectal cancer. Science 357, 55–60 (2017). https://dx.doi.org/10.1126/science.aai8515
  18. Saif, M. W. et al. Phase 1 study of the anti-vascular endothelial growth factor receptor 3 monoclonal antibody LY3022856/IMC-3C5 in patients with advanced and refractory solid tumors and advanced colorectal cancer. Cancer Chemother Pharmacol 78, 815–824 (2016). https://dx.doi.org/10.1007/s00280-016-3134-3
  19. Falchook, G. S. et al. A first-in-human phase I study of VGX-100, a selective anti-VEGF-C antibody, alone and in combination with bevacizumab in patients with advanced solid tumors. J. Clin. Oncol. 32:5s, (2014). http://www.opthea.com/pub/tinymce/scientific/VGX-100%20ASCO%20Poster%202...
  20. Shord, S. S., Bressler, L. R., Tierney, L. A., Cuellar, S. & George, A. Understanding and managing the possible adverse effects associated with bevacizumab. American Journal of Health-System Pharmacy 66, 999–1013 (2009). https://dx.doi.org/10.2146/ajhp080455
  21. Karkkainen, M. J. et al. A model for gene therapy of human hereditary lymphedema. PNAS 98, 12677–12682 (2001). http://dx.doi.org/10.1073/pnas.221449198
  22. Honkonen, K. M. et al. Lymph Node Transfer and Perinodal Lymphatic Growth Factor Treatment for Lymphedema. Annals of Surgery May 2013 257, 961–967 (2013). http://dx.doi.org/10.1097/SLA.0b013e31826ed043
  23. Herantis Pharma. Lymfactin® for lymphedema. (2015). http://herantis.com/pipeline/lymfactin-for-lymphedema
  24. Nakamura, K., Radhakrishnan, K., Wong, Y. M. & Rockson, S. G. Anti-Inflammatory Pharmacotherapy with Ketoprofen Ameliorates Experimental Lymphatic Vascular Insufficiency in Mice. PLOS ONE 4, e8380 (2009). https://dx.doi.org/10.1371/journal.pone.0008380
  25. Tian, W. et al. Leukotriene B4 antagonism ameliorates experimental lymphedema. Science Translational Medicine 9, eaal3920 (2017). https://dx.doi.org/10.1126/scitranslmed.aal3920
Table: