We therefore hypothesize that the high VEGF-levels found in GBM in vivo do not reduce the radiosensitivity of endothelial cells, which is thought to contribute to the strong radioresistance of the tumor vasculature.
We show that VEGF pathway blockade resulted in tumor growth retardation and inhibition of tumor vasculature in preclinical models of pediatric glioblastoma and breast cancer brain metastases, suggesting that multiparametric MRI can provide a powerful adjunct to accelerate the development of antiangiogenic therapies for use in these patient populations.
We previously reported that the silencing of the endothelial VEGF receptor (VEGFR2) by a liposomal siRNA system (RGD-MEND) resulted in an enhanced intratumoral distribution of polyethylene glycol (PEG)-modified liposomes (LPs) in a renal cell carcinoma, a type of hypervascularized cancer, although the inhibition of VEGF signaling would be expected to decrease the permeability of the tumor vasculature.
We conclude that inhibition of Ang2 slows tumor growth by limiting the expansion of the tumor vasculature by sprouting angiogenesis, in a manner that is complemented by concurrent inhibition of VEGF and leads to reduced proliferation and increased apoptosis of tumor cells.
These results suggest that the unique dependence on VEGF of blood vessels lacking periendothelial cells can be exploited to reduce an existing tumor vasculature.
These results demonstrate that the host microvascular environment determines the morphology and function of the tumor vasculature and that endothelia from different tissues vary in their ability to express the VEGF receptors given identical stimuli.
The enhanced tumor oxygenation after oxygen microbubble treatment inhibited hypoxia inducible factor-1 alpha (HIF-1α)/vascular endothelial growth factor (VEGF) pathway to improve the morphology and function of tumor vasculature.
The VEGF receptors, kinase domain region (KDR) and Fms-like-tyrosine kinase (Flt-1), also were upregulated in the tumor vasculature of glioblastoma multiforme, anaplastic oligodendrogliomas, and ependymomas with necrosis, whereas the astrocytomas grade II, anaplastic astrocytomas, and oligodendroglioma tumors tended to express a weak to nondetectable signal.
Targeting angiogenesis by inhibition of vascular endothelial growth factor (VEGF) receptor tyrosine kinases (RTKs) of the tumor vasculature with small molecules is a promising new therapy.
Rh-endostatin could normalize the tumor vasculature and microenvironment in Lewis lung carcinoma probably via modulation of the balance between vascular endothelial growth factor-A and thrombospondin-1.
Our data suggest that intervention of this non-VEGF reciprocal interaction loop for the tumor vasculature could be an important therapeutic target for the treatment of cancer and metastasis.
Multimodal targeting of tumor vasculature and cancer stem-like cells in sarcomas with VEGF-A inhibition, HIF-1α inhibition, and hypoxia-activated chemotherapy.
Mouse and human T cells were engineered to express a chimeric antigen receptor (CAR) targeted against VEGFR-2, which is overexpressed in tumor vasculature and is responsible for VEGF-mediated tumor progression and metastasis.
Most antiangiogenic therapies currently being evaluated in clinical trials target the vascular endothelial growth factor pathway; however, the tumor vasculature can acquire resistance to vascular endothelial growth factor-targeted therapy by shifting to other angiogenesis mechanisms.
Inhibitors of Vascular Endothelial Growth Factor target both tumor vasculature and cancer cells that have hijacked VEGF Receptors (VEGFRs) signaling for tumor growth-promoting activities.
In particular, PTP4A3 is expressed in the tumor vasculature and has been proposed to be a direct target of vascular endothelial growth factor (VEGF) signaling in endothelial cells.
GC samples from 54 surgical specimens were subjected to immunohistochemical examination of IL-6, VEGF, and tumor microvessels, and results showed that IL-6 was positively correlated with VEGF expression and tumor vasculature.
Furthermore, neither overexpression of VEGF or a high vascular density or hyperpermeability of tumor vasculature is necessarily followed by metastasis.
Flt-1, a receptor for vascular endothelial growth factor, is known to display dysregulated expression in both tumor vasculature and tumor cells per se, suggesting that the flt-1 promoter might be a useful candidate to achieve tumor-specific transgene expression.
Different isoforms of VEGF-A (mainly VEGF₁₂₁, VEGF₁₆₅ and VEGF189) have been shown to display particular angiogenic properties in the generation of a functional tumor vasculature.