Several studies report the key role of the
vascular endothelial growth factor (
VEGF) signaling on angiogenesis and on
tumor growth. This has led to the development of a number of
VEGF-targeted agents to treat
cancer patients by disrupting the
tumor blood vessel supply. Of them,
bevacizumab, an FDA-approved humanized
monoclonal antibody against
VEGF, is the most promising. Although the use of
antibodies targeting the
VEGF pathway has shown clinical benefits associated with a reduction in the
tumor blood vessel density, the inhibition of
VEGF-driven vascular effects is only part of the functional mechanism of these therapeutic agents in the
tumor ecosystem. Compelling reports have demonstrated that
VEGF confers, in addition to the activation of angiogenesis-related processes, immunosuppressive properties in
tumors. It is also known that structural remodeling of the
tumor blood vessel bed by anti-
VEGF approaches affect the influx and activation of immune cells into
tumors, which might influence the therapeutic results. Besides that, part of the
therapeutic effects of antiangiogenic
antibodies, including their role in the
tumor vascular network, might be triggered by
Fc receptors in an
antigen-independent manner. In this mini-review, we explore the role of
VEGF inhibitors in the tumor microenvironment with focus on the immune system, discussing around the functional contribution of both
bevacizumab's Fab and Fc domains to the therapeutic results and the combination of
bevacizumab therapy with other immune-stimulatory settings, including adjuvant-based
vaccine approaches.