Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0178874 (tumor progression)
 40,807 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We studied whether the expression of the Neuropilin (NRP) gene was correlated with clinicopathological features in glioma. We examined the gene expression of vascular endothelial growth factor (VEGF)-A, Flt-1, KDR, NRP1 and NRP2 in 37 gliomas by real time reverse transcriptase PCR (real time RT-PCR) as well as immunohistochemical analysis. The vascular counts of each tumor were evaluated by anti-CD34 antibody. NRP1 mRNA overexpression was significantly higher in neoplastic tissue compared to normal brain tissue samples. The higher grade of glioma overexpressed the NRP1 gene significantly (p=0.0015). The glioma patients with NRP1 overexpression showed a poorer prognosis (p=0.0202) than those without such overexpression. NRP1 was observed in the glioma cells by immunohistochemical analyses. VEGF-A and VEGFR overexpression did not show any correlation with the clinicopathological features, including NRP expression. These results suggest that NRP1 overexpression, rather than VEGF-A or VEGFR, contributes to tumor progression and has clinical significance for glioma.
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PMID:Overexpression of the neuropilin 1 (NRP1) gene correlated with poor prognosis in human glioma. 1516 Sep 92

Angiogenesis is a precondition to invasion and metastasis for all solid tumors. Vascular endothelial growth factor (VEGF) and its family of receptors (VEGFR) play a critical role in cancer progression by promoting new blood vessel formation. Overexpression of VEGF and VEGFR has been correlated with poor prognosis in a variety of malignancies. In this era of targeted therapies for cancer, inhibiting angiogenesis through antiangiogenic and/or vascular targeting agents seems logical. Disturbing the angiogenesis process is an alternative or complementary strategy to inhibition of growth factor signaling. Blocking angiogenesis may enhance conventional anticancer treatments such as radiation therapy in situations where tumors are unresponsive to current antigrowth factor efforts. Compounds currently under investigation in cancer therapy include anti-VEGF/VEGFR antibodies, small molecule VEGFR tyrosine kinase inhibitors, antisense suppression of VEGF, immunotherapy, viral-directed targeting of VEGFR signaling, ribozymes, and various toxin conjugates. Preclinical investigations are exploring the benefits of combining angiogenic inhibitors with radiation. This article will provide an overview of these preclinical studies and the rationale for this therapeutic strategy in the treatment of non-small-cell lung cancer.
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PMID:Angiogenesis inhibitors: a rational strategy for radiosensitization in the treatment of non-small-cell lung cancer? 1531 Apr 17

The RAS/RAF signaling pathway is an important mediator of tumor cell proliferation and angiogenesis. The novel bi-aryl urea BAY 43-9006 is a potent inhibitor of Raf-1, a member of the RAF/MEK/ERK signaling pathway. Additional characterization showed that BAY 43-9006 suppresses both wild-type and V599E mutant BRAF activity in vitro. In addition, BAY 43-9006 demonstrated significant activity against several receptor tyrosine kinases involved in neovascularization and tumor progression, including vascular endothelial growth factor receptor (VEGFR)-2, VEGFR-3, platelet-derived growth factor receptor beta, Flt-3, and c-KIT. In cellular mechanistic assays, BAY 43-9006 demonstrated inhibition of the mitogen-activated protein kinase pathway in colon, pancreatic, and breast tumor cell lines expressing mutant KRAS or wild-type or mutant BRAF, whereas non-small-cell lung cancer cell lines expressing mutant KRAS were insensitive to inhibition of the mitogen-activated protein kinase pathway by BAY 43-9006. Potent inhibition of VEGFR-2, platelet-derived growth factor receptor beta, and VEGFR-3 cellular receptor autophosphorylation was also observed for BAY 43-9006. Once daily oral dosing of BAY 43-9006 demonstrated broad-spectrum antitumor activity in colon, breast, and non-small-cell lung cancer xenograft models. Immunohistochemistry demonstrated a close association between inhibition of tumor growth and inhibition of the extracellular signal-regulated kinases (ERKs) 1/2 phosphorylation in two of three xenograft models examined, consistent with inhibition of the RAF/MEK/ERK pathway in some but not all models. Additional analyses of microvessel density and microvessel area in the same tumor sections using antimurine CD31 antibodies demonstrated significant inhibition of neovascularization in all three of the xenograft models. These data demonstrate that BAY 43-9006 is a novel dual action RAF kinase and VEGFR inhibitor that targets tumor cell proliferation and tumor angiogenesis.
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PMID:BAY 43-9006 exhibits broad spectrum oral antitumor activity and targets the RAF/MEK/ERK pathway and receptor tyrosine kinases involved in tumor progression and angiogenesis. 1546 6

Cancer growth and progression is often critically influenced by the production of vascular endothelial growth factor (VEGF), a key mediator of angiogenesis. VEGF produced by tumor cells stimulates endothelial cell growth through the binding and activation of the KDR/Flk-1 receptor (VEGFR-2) on endothelial cells. Recently, some human breast cancer epithelial cells have been shown to express VEGF receptors, suggesting a potential autocrine-mediated growth stimulation of a subset of cancers by VEGF. We demonstrate that mammary tumors in the C3(1)/Tag transgenic model express VEGF and VEGF receptors and tumor growth is stimulated by this autocrine mechanism. GW654652, an indazolylpyrimidine, is a VEGFRs tyrosine kinase inhibitor that dramatically reduces both angiogenesis and tumor cell growth in this model, as demonstrated using both in vitro and in vivo assays. GW654652 significantly decreased cell proliferation and induced apoptosis in human umbilical vein endothelial cells and M6 mammary tumor cells derived from C3(1)/Tag (Tag: simian virus 40 T-antigen) transgenic mice. A 75% reduction in VEGF-induced angiogenesis was observed with GW654652 using the chick chorioallantoic membrane assay, whereas GW654652 produced an approximately 85% reduction in angiogenesis as assessed by the Matrigel plug assay. A profound inhibitory effect on tumor growth in the C3(1)/Tag transgenic model of human breast cancer was observed with oral administration of GW654652 as measured by delayed tumor onset, decreased multiplicity, reduced tumor volume, and extended animal survival. The antitumor effects of GW654652 were associated with reduced tumor vascularization and no apparent toxicity. Tumor growth, however, rapidly advanced following cessation of treatment. This is the first demonstration that a VEGF receptor inhibitor, GW654652, has a strong inhibitory effect on angiogenesis and tumor progression in a transgenic model of mammary cancer, suggesting that this is a useful approach for preclinical testing of such agents.
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PMID:Inhibition of VEGF receptors significantly impairs mammary cancer growth in C3(1)/Tag transgenic mice through antiangiogenic and non-antiangiogenic mechanisms. 1559 23

The vascular endothelial growth factor-A (VEGF-A) is a cytokine that promotes angiogenesis through the activation of two tyrosine kinase receptors, VEGFR-1 and VEGFR-2, on vascular endothelial cells. Moreover, several experimental evidences indicate that VEGF-A may also play a role in tumor progression by acting on neoplastic cells expressing VEGFRs. In this study we show that human melanoma cells that simultaneously produce VEGF-A and express VEGFRs exhibit a higher spontaneous ability to invade the extracellular matrix (ECM) than melanoma cells not expressing either VEGF-A or VEGFRs. Exposure of VEGFR expressing melanoma cells to exogenous VEGF-A further increases their ability to invade the ECM. Moreover, an inhibitor of VEGFR tyrosine kinase activity is able to abrogate VEGF-A-induced stimulation of ECM invasion. A cell clone (13443/N2) derived from a VEGF-A responsive melanoma cell line and expressing high levels of VEGFR-2 invades the ECM eight-fold more efficiently than a cell clone derived from the same cell line and expressing extremely low levels of the receptor. Exposure of 13443/N2 cells to VEGF-E, which selectively binds and activates VEGFR-2, increases their ability to invade the ECM. Finally, the expression of the VEGF-A mRNA antisense sequence in 13443/N2 cells markedly reduces the release of VEGF-A and ECM invasion. In conclusion, our data show for the first time that a VEGF-A-driven autocrine loop promotes human melanoma cell ability to invade the ECM, and strongly support the hypothesis that activation of VEGFR-2 plays a primary role in this process.
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PMID:An autocrine loop directed by the vascular endothelial growth factor promotes invasiveness of human melanoma cells. 1627 19

The angiogenic factor called vascular endothelial growth factor (VEGF)-D is a ligand for VEGF receptor-2 (VEGFR-2/KDR) and receptor-3 (VEGFR-3/Flt-4). It is implicated in the development of lymphatic vessels and promotion of lymphatic metastasis. The purpose of this study was to investigate the prognostic significance of VEGF-D expression in patients with gastric carcinoma. We assessed the expression of VEGF-D in gastric carcinoma by immunohistochemistry on 143 consecutive patients' stored sections and evaluated the lymphatic vessel count (LVC) in tumors using the novel selective lymphatic endothelium marker D2-40. VEGF-D expression was observed in 55 (39%) tumor sections. The expression of VEGF-D correlated significantly with tumor size, T of the TNM classification, lymphatic and venous system invasion, LVC, lymph node metastasis, M of TNM, and pTNM stage. Multivariate analysis indicated that VEGF-D expression was an independent prognostic factor for both relapse-free survival (RFS) and overall survival (OS). Our data indicate the involvement of VEGF-D in tumor progression via lymphoangiogenic pathways. Practically, VEGF-D expression can be useful for predicting RFS and OS in patients with gastric carcinoma.
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PMID:Prognostic significance of vascular endothelial growth factor D in gastric carcinoma. 1631 50

Tumors of the oral cavity are highly vascularized malignancies. Disruption of neovascular networks was shown to limit the access of nutrients and oxygen to tumor cells and inhibit tumor progression. Here, we evaluated the effect of the activation of an artificial death switch (iCaspase-9) expressed in neovascular endothelial cells on the progression of oral tumors. We used biodegradable scaffolds to co-implant human dermal microvascular endothelial cells stably expressing iCaspase-9 (HDMEC-iCasp9) with oral cancer cells expressing luciferase (OSCC3-luc or UM-SCC-17B-luc) in immunodeficient mice. Alternatively, untransduced HDMEC were co-implanted with oral cancer cells, and a transcriptionaly targeted adenovirus (Ad-VEGFR2-iCasp-9) was injected locally to deliver iCaspase-9 to neovascular endothelial cells. In vivo bioluminescence demonstrated that tumor progression was inhibited, and immunohistochemistry showed that microvessel density was decreased, when iCaspase-9 was activated in tumor-associated microvessels. We conclude that activation of iCaspase-9 in neovascular endothelial cells is sufficient to inhibit the progression of xenografted oral tumors.
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PMID:Activation of iCaspase-9 in neovessels inhibits oral tumor progression. 1663 57

Activating mutations in Ras and B-RAF were identified in several human cancers. In addition, several receptor tyrosine kinases, acting upstream of Ras, were found either mutated or overexpressed in human tumors. Because oncogenic activation of the Ras/RAF pathway may lead to a sustained proliferative signal resulting in tumor growth and progression, inhibition of this pathway represents an attractive approach for cancer drug discovery. A novel class of biaryl urea that inhibits C-RAF kinase was discovered using a combination of medicinal and combinatorial chemistry approaches. This effort culminated in the identification of the clinical candidate BAY 43-9006 (Sorafenib, Nexavar), which has recently been approved by the FDA for advanced renal cell carcinoma in phase III clinical trials. Sorafenib inhibited the kinase activity of both C-RAF and B-RAF (wild type and V600E mutant). It inhibited MEK and ERK phosphorylation in various cancer cell lines and tumor xenografts and exhibited potent oral antitumor activity in a broad spectrum of human tumor xenograft models. Further characterization of sorafenib revealed that this molecule was a multikinase inhibitor that targeted the vascular endothelial growth factor receptor family (VEGFR-2 and VEGFR-3) and platelet-derived growth factor receptor family (PDGFR-beta and Kit), which play key roles in tumor progression and angiogenesis. Thus, sorafenib may inhibit tumor growth by a dual mechanism, acting either directly on the tumor (through inhibition of Raf and Kit signaling) and/or on tumor angiogenesis (through inhibition of VEGFR and PDGFR signaling). In phase I and phase II clinical trials, sorafenib showed limited side effects and, more importantly, disease stabilization. This agent is currently being evaluated in phase III clinical trials in renal cell and hepatocellular carcinomas.
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PMID:Sorafenib (BAY 43-9006, Nexavar), a dual-action inhibitor that targets RAF/MEK/ERK pathway in tumor cells and tyrosine kinases VEGFR/PDGFR in tumor vasculature. 1675 55

Improvements in our understanding of the molecular basis of cancer have led to the clinical development of protein kinase inhibitors, which target pivotal molecules involved in intracellular signaling pathways implicated in tumorigenesis and progression. These novel targeted agents have demonstrated activity against a wide range of solid tumors, are generally better tolerated than standard chemotherapeutics, and may revolutionize the management of advanced refractory cancer. The ubiquitous Raf serine/threonine kinases are pivotal molecules within the Raf/mitogen extracellular kinase (MEK)/extracellular signal-related kinase (ERK) signaling pathway, which regulates cellular proliferation and survival. Raf kinase isoforms (wild-type Raf-1 or the b-raf V600E oncogene) are overactivated in a variety of solid tumor types, including renal cell carcinoma (RCC), hepatocellular carcinoma (HCC), non-small cell lung cancer (NSCLC), melanoma, and papillary thyroid carcinoma. In this review, the role of Raf in normal cells and in cancer is discussed, and an overview is given of Raf inhibitors currently in development, focusing on sorafenib tosylate (BAY 43-9006 or sorafenib). Sorafenib is the first oral multi-kinase inhibitor to be developed that targets Raf kinases (Raf-1, wild-type B-Raf, and b-raf V600E), in addition to receptor tyrosine kinases associated with angiogenesis (vascular endothelial growth factor receptor [VEGFR]-2/-3, platelet-derived growth factor receptor [PDGFR]-beta) or tumor progression (Flt-3, c-kit). Preclinical and clinical sorafenib data that led to its recent approval for the treatment of advanced RCC are summarized, along with current thinking on sorafenib's mechanism of effect on the tumor and tumor vasculature in melanoma and RCC.
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PMID:Role of Raf kinase in cancer: therapeutic potential of targeting the Raf/MEK/ERK signal transduction pathway. 1689 Jul 95

Increased levels of vascular endothelial growth factor (VEGF) are associated with a poor response of breast cancer to anti-hormone treatment. Although VEGF is regarded as an endothelial-specific growth factor, recent reports have shown that VEGF can promote proliferation of other cell types, including breast tumor cells. We have characterized the proliferative effects of VEGF in breast cancer cell lines that are commonly used for understanding the role of estrogens, progestins, and anti-hormones on tumor growth. Since steroid hormones can increase the level of VEGF in certain breast cancer cells, we evaluated the effects of exogenous VEGF on the growth-suppressive effects of anti-estrogen (ICI 182,780) and RU-486 (anti-progestin mifepristone) in human breast cancer cells. VEGF165 and VEGF121 increased the proliferation of tumor cell lines that expressed VEGFR-2 (VEGF receptor 2) (flk/kdr) via the extracellular signal-regulated kinase/mitogen activated protein kinase (ERK/MAPK) pathway. Furthermore, VEGF induced the expression of the anti-apoptotic protein Bcl-2 and blocked down-regulation of Bcl-2 by ICI 182,780 and induced Bcl-2 in BT-474 and T47-D cells even in the presence of RU-486. Increased Bcl-2 levels in response to VEGF were associated with increased proliferation and survival of tumor cells even in the presence of anti-hormones. These results suggest that VEGF stimulates proliferation of VEGFR2-positive tumor cells, promotes survival via the expression and activity of Bcl-2 and overrides the growth-suppressive effects of anti-hormones. This represents a potential explanation for anti-hormone resistance and tumor progression in clinical samples. Thus, it may be useful to use combined modality treatment involving anti-hormones and anti-angiogenic agents to treat breast cancers that express elevated levels of VEGF.
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PMID:Vascular endothelial growth factor induces proliferation of breast cancer cells and inhibits the anti-proliferative activity of anti-hormones. 1695 39


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