Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027819 (neuroblastoma)
 27,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Direct experimental evidence shows that tumor growth and metastases are angiogenesis-dependent. Neuroblastoma (NB) is the most common extracranial malignant solid tumor of childhood. In this study, we investigated 2 human NB cell lines, LAN-5 and GI-LI-N, for their capacity to secrete 2 extracellular matrix-degrading enzymes, MMP-2 and MMP-9, and to induce in vitro human microvascular endothelial cells (EC) to proliferate and in vivo angiogenesis in the chick embryo chorio-allantoic membrane (CAM) assay. Conditioned medium (CM) from both cell lines stimulated in vitro EC proliferation and the effect of LAN-5 CM was higher than that of GI-LI-N cells. Moreover, anti-VEGF, but not anti-FGF2 antibodies, prevented growth increment of EC. NB cell lines secreted the active form of MMP-2 almost exclusively, LAN-5 cells more than GI-LI-N cells. Both cell lines, LAN-5 cells more than GI-LI-N ones, induced angiogenesis in the CAM assay. Our data suggest that the 2 NB cell lines are angiogenic, to LAN-5 cells more than GI-LI-N ones. LAN-5 cells are indeed endowed with a more aggressive and invasive phenotype.
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PMID:Human neuroblastoma cells produce extracellular matrix-degrading enzymes, induce endothelial cell proliferation and are angiogenic in vivo. 966 9

Various conventional chemotherapeutic drugs can block angiogenesis or even kill activated, dividing endothelial cells. Such effects may contribute to the antitumor efficacy of chemotherapy in vivo and may delay or prevent the acquisition of drug-resistance by cancer cells. We have implemented a treatment regimen that augments the potential antivascular effects of chemotherapy, that is devoid of obvious toxic side effects, and that obstructs the development of drug resistance by tumor cells. Xenografts of 2 independent neuroblastoma cell lines were subjected to either continuous treatment with low doses of vinblastine, a monoclonal neutralizing antibody (DC101) targeting the flk-1/KDR (type 2) receptor for VEGF, or both agents together. The rationale for this combination was that any antivascular effects of the low-dose chemotherapy would be selectively enhanced in cells of newly formed vessels when survival signals mediated by VEGF are blocked. Both DC101 and low-dose vinblastine treatment individually resulted in significant but transient xenograft regression, diminished tumor vascularity, and direct inhibition of angiogenesis. Remarkably, the combination therapy resulted in full and sustained regressions of large established tumors, without an ensuing increase in host toxicity or any signs of acquired drug resistance during the course of treatment, which lasted for >6 months. This article may have been published online in advance of the print edition. The date of publication is available from the JCI website, http://www.jci.org.
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PMID:Continuous low-dose therapy with vinblastine and VEGF receptor-2 antibody induces sustained tumor regression without overt toxicity. 1077 48

Retinoids are a class of natural or synthetic compounds that participate in the control of cell proliferation, differentiation and fetal development. The synthetic retinoid fenretinide (HPR) inhibits carcinogenesis in various animal models. Retinoids have also been suggested to be effective inhibitors of angiogenesis. The effects of HPR on certain endothelial cell functions were investigated in vitro, and its effects on angiogenesis was studied in vivo, by using the chorioallantoic membrane (CAM) assay. HPR inhibited vascular endothelial growth factor- (VEGF-) and fibroblast growth factor-2- (FGF-2)-induced endothelial cell proliferation without affecting endothelial motility; moreover, HPR inhibited growth factor-induced angiogenesis in the CAM assay. Furthermore, a significant antiangiogenic potential of HPR has also been observed in neuroblastoma (NB) biopsy-induced angiogenesis in vivo. We previously demonstrated that supernatants derived from NB cell lines stimulated endothelial cell proliferation. In the present study, we found that this effect was abolished when NB cells were incubated in the presence of HPR. VEGF- and FGF-2-specific ELISA assays, performed on both NB cells derived from conditioned medium and cellular extracts, indicated no consistent effect of HPR on the level of these angiogenic cytokines. Moreover, RT-PCR analysis of VEGF and FGF-2 gene expression confirmed the above lack of effect. HPR was also able to significantly repress the spontaneous growth of endothelial cells, requiring at least 48-72 hr of treatment with HPR, followed by a progressive accumulation of cells in G(1) at subsequent time points. Finally, immunohistochemistry experiments performed in the CAM assay demonstrated that endothelial staining of both VEGF receptor 2 and FGF-2 receptor-2 was reduced after implantation of HPR-loaded sponges, as compared to control CAMs. These data suggest that HPR exerts its antiangiogenic activity through both a direct effect on endothelial cell proliferative activity and an inhibitory effect on the responsivity of the endothelial cells to the proliferative stimuli mediated by angiogenic growth factors.
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PMID:Inhibition of neuroblastoma-induced angiogenesis by fenretinide. 1174 8

Angiogenesis is an indispensable prerequisite for the progression and metastasis of solid malignancies. Tumor angiogenesis appears to be governed by alterations of tumor suppressor or oncogenes operant in a broad range of tumors. We have addressed this issue in neuroblastoma, a malignancy characterized by the near-exclusive amplification and overexpression of the N-Myc oncogene. Here, we report that N-Myc overexpression results in down-regulation of interleukin-6 (IL-6) and that IL-6 is an inhibitor of endothelial cell proliferation and VEGF-induced rabbit corneal angiogenesis. STAT3 is instrumental for IL-6 activity as infection with adenoviruses expressing a phosphorylation deficient STAT3 mutant renders endothelial cells insensitive to the antiproliferative action of IL-6. Finally, though IL-6 does not influence neuroblastoma cell growth, IL-6-expressing xenograft tumors in mice exhibit reduced neovascularization and suppressed growth. Our data shed new light on the mechanisms by which N-myc oncogene amplification enhances the malignant phenotype in neuroblastomas.
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PMID:N-myc oncogene overexpression down-regulates IL-6; evidence that IL-6 inhibits angiogenesis and suppresses neuroblastoma tumor growth. 1203 57

Human neuroblastoma (NB) tumors elaborate angiogenic peptides, and enhanced angiogenesis correlates with their aggressive behavior, metastatic spread and poor clinical outcome. Hence, inhibition of angiogenic factor production may represent a potential therapeutic target for NB treatment. There is currently little information regarding the stimuli that control NB production of angiogenic mediators. In this study, we analyzed the effects of hypoxia, a common feature of solid tumors and a major drive to tumor angiogenesis, and of PA, a tryptophan catabolite produced under inflammatory conditions and endowed with several biologic properties, on the production of the angiogenic activator VEGF by advanced-stage human NB cell lines. We demonstrate that both stimuli are potent inducers of VEGF expression and secretion. VEGF upregulation by PA involved iron chelation because iron sulfate prevented this effect whereas the iron-chelating agent DFX induced VEGF production. Conversely, the CDK inhibitor Flp completely blocked VEGF induction by hypoxia. This effect occurred as early as 3 hr after stimulation and did not require de novo protein synthesis. Moreover, Flp exerted similar inhibitory activity on VEGF induction by PA or DFX, suggesting that this compound targets an essential step in the signaling pathway that leads to VEGF expression. Our findings demonstrate that PA can modulate angiogenic factor production by tumor cells and establish the importance of Flp as an inhibitor of VEGF production by human NB.
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PMID:Flavopiridol inhibits vascular endothelial growth factor production induced by hypoxia or picolinic acid in human neuroblastoma. 1211 98

Vascular endothelial growth factor A (VEGF-A) and its receptor tyrosine kinases located on endothelial cells seem to play an important role in the multistep pathway of angiogenesis. SU5416 is a small molecule which inhibits angiogenesis by acting as an inhibitor of VEGF receptor-2 tyrosine kinase. We have developed a reproducible murine model for neuroblastoma, a childhood cancer, based on s.c. xenotransplantation of SH-SY5Y neuroblastoma cells. We found that SH-SY5Y cells expressed VEGF-A on both the mRNA and protein levels, that plasma concentrations of VEGF-A were significantly elevated in animals with neuroblastoma with a volume > 1.4 ml, and that there was a correlation between VEGF-A levels in plasma and tumor size in untreated tumor-bearing animals. Treatment with SU5416 reduced the growth of neuroblastoma tumors by 65% without apparent toxicity. SU5416 treatment also suppressed tumor angiogenesis, despite an increase in plasma VEGF-A levels per ml tumor volume during therapy. Our experimental data suggest that the angiogenesis inhibitor SU5416 may be beneficial in the treatment of solid tumors of childhood such as neuroblastoma.
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PMID:Importance of vascular endothelial growth factor A in the progression of experimental neuroblastoma. 1290 18

Thalidomide has previously been shown to have anti-angiogenic properties. More recently, clinical efficacy of this agent has been demonstrated in multiple myeloma and prostate cancer. Neuroblastoma is the most frequent solid tumor of the abdomen of childhood, yet children with this disease frequently have metastases at presentation. Such patients have a very poor prognosis with current therapies. Thus, new approaches are needed. We have previously shown that VEGF antagonists can inhibit neoangiogenesis and tumor growth in experimental neuroblastoma. In this study, we investigated the anti-angiogenic and anti-tumor properties of thalidomide in a xenograft model of human neuroblastoma. Tumors were induced in athymic mice using the human neuroblastoma cell line NGP. Intraperitoneal thalidomide (100 mg/kg/dose) or vehicle was administered beginning one week after implantation, and animals euthanized at six weeks. Thalidomide treatment did not significantly alter tumor growth as compared with controls. However, thalidomide suppressed angiogenesis, as demonstrated both by fluorescein angiography and immunohistochemical staining, and induced apoptosis of endothelial cells in neuroblastoma xenografts. Quantification of microvessel density demonstrated a significant reduction of vasculature in treated tumors (p<0.004). Thalidomide induced co-option of host vasculature, an effect noted previously after VEGF blockade. This study demonstrates that thalidomide has anti-angiogenic properties in experimental neuroblastoma.
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PMID:Thalidomide is anti-angiogenic in a xenograft model of neuroblastoma. 1461 37

In previous studies, we demonstrated that human neuroblastoma cells are equipped with the machinery to direct their homing to bone marrow. These tumor cells express the CXCR4 receptor for the bone marrow stroma-derived chemokine CXCL12 (SDF-1) and secrete the CXCL12 ligand. The present study was undertaken to explore possible differences in gene-expression patterns between neuroblastoma variants that over-express CXCR4 (designated STH cells) and those which express very little of this receptor (STL cells). The results of the study clearly indicate that these variants show a differential gene-expression profile. They differ in expression of some integrins such as VLA2, VLA3 and VLA6, of neuroendocrine-markers such as CD56 and synaptophysin, in the expression of c-kit and in the secretion of certain cytokines and growth factors such as TNFalpha, SDF-1, VEGF, IL-8, GM-CSF and IP-10. We hypothesize that these differences are due to an autocrine SDF-1alpha-CXCR4 axis.
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PMID:The tumor microenvironment: CXCR4 is associated with distinct protein expression patterns in neuroblastoma cells. 1508 41

To inhibit tumor-induced angiogenesis, the VEGF signaling pathway was targeted using AAV vectors encoding a VEGF decoy receptor, a truncated, soluble form of the murine VEGF receptor-2 (tsFlk-1). This approach initially had significant anti-neuroblastoma efficacy in murine xenograft models of local and metastatic disease, but when higher circulating levels of tsFlk-1 were established, tumor growth was more aggressive than even in control mice. Part of the mechanism for this apparent tumor resistance was increased human VEGF expression by the tumor cells. However, further investigation revealed that although a greater amount of VEGF could be bound by higher levels of tsFlk-1, more VEGF also existed in an unbound state and was, therefore, available to support angiogenesis. This novel, tumor-independent mechanism for resistance to antiangiogenic strategies suggests that careful titering of angiogenesis inhibitors may be required to achieve maximal antitumor efficacy and avoid therapy resistance mediated, in part, by ligand bioavailability. This has important implications for therapeutic strategies that use decoy receptors and other agents, such as antibodies, to bind angiogenic factors, in an attempt to inhibit tumor neovascularization.
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PMID:Careful decoy receptor titering is required to inhibit tumor angiogenesis while avoiding adversely altering VEGF bioavailability. 1566 42

Secreted protein, acidic and rich in cysteine (SPARC), is a multifunctional matricellular glycoprotein. In vitro, SPARC has antiangiogenic properties, including the ability to inhibit the proliferation and migration of endothelial cells stimulated by bFGF and VEGF. Previously, we demonstrated that platelet-derived SPARC also inhibits angiogenesis and impairs the growth of neuroblastoma tumors in vivo. In the present study, we produced rhSPARC in the transformed human embryonic kidney cell line 293 and show that the recombinant molecule retains its ability to inhibit angiogenesis. Although 293 cell proliferation was not affected by exogenous expression of SPARC in vitro, growth of tumors formed by SPARC-transfected 293 cells was significantly impaired compared to tumors comprised of wild-type cells or 293 cells transfected with a control vector. Consistent with its function as an angiogenesis inhibitor, significantly fewer blood vessels were seen in SPARC-transfected 293 tumors compared to controls, and these tumors contained increased numbers of apoptotic cells. Light microscopy revealed small nests of tumor cells surrounded by abundant stromal tissue in xenografts with SPARC expression, whereas control tumors were comprised largely of neoplastic cells with scant stroma. Mature, covalently cross-linked collagen was detected in SPARC-transfected 293 xenografts but not in control tumors. Our studies suggest that SPARC may regulate tumor growth by inhibiting angiogenesis, inducing tumor cell apoptosis and mediating changes in the deposition and organization of the tumor microenvironment.
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PMID:SPARC expression is associated with impaired tumor growth, inhibited angiogenesis and changes in the extracellular matrix. 1605 22


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