Inhibition of glioblastoma angiogenesis and invasion by combined treatments directed against vascular endothelial growth factor receptor-2, epidermal growth factor receptor, and vascular endothelial-cadherin.
OBJECTIVE
Inhibition of angiogenesis can influence tumor cell invasion and metastasis. We previously showed that blockade of vascular endothelial growth factor receptor-2 (VEGFR-2) with the monoclonal antibody DC101 inhibited intracerebral glioblastoma growth but caused increased tumor cell invasion along the preexistent vasculature. In the present study, we attempted to inhibit glioma cell invasion using a monoclonal antibody against the epidermal growth factor receptor (EGFR), which in the context of human glioblastomas, has been implicated in tumor cell invasion. In addition, we analyzed whether blockade of vascular endothelial (VE)-cadherin as a different antiangiogenic target could also inhibit glioblastoma angiogenesis and growth.


METHODS
Nude mice who received intracerebral glioblastoma xenografts were treated using monoclonal antibodies against VEGFR-2 (DC101), EGFR (C225), and VE-cadherin (E4G10) either alone or in different combinations.


RESULTS
Increased tumor cell invasion provoked by DC101 monotherapy was inhibited by 50% to 66% by combined treatment with C225 and DC101. C225 inhibited glioblastoma cell migration in vitro, but had no effect on the volume of the main tumor mass or on tumor cell proliferation or apoptosis in vivo, either alone or in combination with DC101. The anti-VE-cadherin monoclonal antibody E4G10 was a weaker inhibitor of tumor angiogenesis and growth than DC101, and also caused a weaker increase in tumor cell invasion.


CONCLUSIONS
Inhibition of angiogenesis achieved by blocking either VEGFR-2 or VE-cadherin can cause increased glioma cell invasion in an orthotopic model. Increased tumor cell invasion induced by potent inhibition of angiogenesis with DC101 could be inhibited by simultaneous blockade of EGFR.
Lamszus
Katrin
K
Department of Neurosurgery, Institute for Anatomy II, University Hospital Hamburg-Eppendorf, Hamburg, Germany. lamszus@uke.uni-hamburg.de
Brockmann
Marc A
MA
Eckerich
Carmen
C
Bohlen
Peter
P
May
Chad
C
Mangold
Ulrich
U
Fillbrandt
Regina
R
Westphal
Manfred
M
D000818:Animals; D000911:Antibodies, Monoclonal / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D015703:Antigens, CD; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D017209:Apoptosis / Q000187:drug effects; D015820:Cadherins / Q000276:immunology; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000378:metabolism; D066246:ErbB Receptors / Q000276:immunology; D005260:Female; D005909:Glioblastoma / Q000098:blood supply / Q000188:drug therapy* / Q000473:pathology; D006801:Humans; D051379:Mice; D016513:Mice, SCID; D009361:Neoplasm Invasiveness; D009389:Neovascularization, Pathologic / Q000473:pathology / Q000517:prevention & control*; D016211:Transforming Growth Factor alpha / Q000494:pharmacology; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000276:immunology; D023041:Xenograft Model Antitumor Assays / Q000379:methods; D000099152:Cadherin 5
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D015820:Cadherins; D066246:ErbB Receptors; D016211:Transforming Growth Factor alpha; D040301:Vascular Endothelial Growth Factor Receptor-2; D000099152:Cadherin 5