UMLS:C0027819 - FACTA Search

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Query: UMLS:C0027819 (neuroblastoma)
27,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Differential regulation as well as target gene specificity of the two hypoxia-inducible factor (HIF)-alpha subunits HIF-1alpha and HIF-2alpha in various tumors and cell lines have been suggested. In breast cancer, the prognostic significance of HIF-1alpha is not clear-cut and that of HIF-2alpha is largely unknown. Using IHC analyses of HIF-1alpha, HIF-2alpha, and vascular endothelial growth factor (VEGF) expression in a tissue microarray of invasive breast cancer specimens from 512 patients, we investigated the expression patterns of the 2 HIF-alpha subunits in relation to established clinicopathologic variables, VEGF expression, and survival. HIF-1alpha and HIF-2alpha protein levels and their effect on survival were additionally analyzed in a second cohort of 179 patients. To evaluate the individual role of each subunit in the hypoxic response and induction of VEGF, HIF-alpha protein and HIF-alpha and VEGF mRNA levels were further studied in cultured breast cancer cells after hypoxic induction and/or knockdown of HIF-alpha subunits by siRNA by Western blot and Quantitative Real-Time PCR techniques. We showed that although HIF-1alpha and HIF-2alpha protein levels in breast cancer specimens were not interrelated, high levels of both HIF-1alpha and HIF-2alpha associated to high VEGF expression. HIF-2alpha expression was an independent prognostic factor associated to reduced recurrence-free and breast cancer-specific survival, whereas HIF-1alpha did not exhibit these correlations. In cultured cells, acute hypoxia induced both HIF-proteins. At prolonged hypoxia, HIF-2alpha remained accumulated, whereas HIF-1alpha protein levels decreased, in agreement with the oxygen level and time-dependent induction of HIFs recently reported in neuroblastoma.
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PMID:Hypoxia-inducible factor-2alpha correlates to distant recurrence and poor outcome in invasive breast cancer. 1901 Aug 93

Tumor hypoxia has been reported to be a negative prognostic factor in a number of tumor sites, which suggests a positive correlation between tumor hypoxia and increased metastatic efficiency. Evidence shows that vascular endothelial growth factor (VEGF) stimulates angiogenesis in tumor growth and mediates neuroprotection to prevent an apoptotic cell death. Human neuroblastoma cells (CHP126) were exposed to moderate hypoxia for different time spans to explore the molecular stress responses. Apoptotic features as an increase of Bax/Bcl-2 ratio and activation of caspase 3 were observed at early period of exposure time, but these effects were reversed with the extension of hypoxic treatment. Hypoxia also activated MAPKs signaling pathways in a time-relative manner, which were involved in the regulation of hypoxia-related resistance of CHP126 cells. Meanwhile, VEGF and its receptor KDR were found to interact with MAPKs signaling pathways except the effect of hypoxia. Furthermore, rhVEGF(165) was utilized to discern that VEGF increased Bcl-2 and procaspase 3 expressions, contributing to a synergistic relationship of an angiogenic response with Bcl-2 in hypoxia via a cross talk, while the activation of ERK MAPK is important for both productions. These altered signals may be critical to predict a poor outcome; therefore, our knowledge provides new insight into apoptosis and angiogenesis control of tumor cells and suggests a strategy based on the blockade of hypoxia-induced VEGF signaling under hypoxia in neuroblastoma.
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PMID:VEGF and Bcl-2 interact via MAPKs signaling pathway in the response to hypoxia in neuroblastoma. 1904 66

Heat shock protein 90 (Hsp90) safeguards the structural integrity and function of many of the key growth regulatory proteins found in malignant cells. Consequently, among the new generation targeted therapeutics, heat shock protein inhibitors have the unique property of being able to target an expansive array of divergent molecular mechanisms involved in cancer growth and metastasis. 17-N-Allylamino-17-demethoxygeldanamycin (17-AAG) is one such agent that has been shown to bind to Hsp90 and thus reduce the stability and activity of many key growth regulatory molecules and pathways. A number of recent clinical trials have investigated the maximum tolerated dose, toxicity and pharmacokinetic profiles of 17-AAG in pediatric patients with recurrent tumors. In this study, we describe the effects of 17-AAG against a panel of neuroblastoma (NB) cell lines with respect to cytotoxicity, target modulation and inhibition of vascular endothelial growth factor (VEGF) expression. 17-AAG was found to inhibit the growth of all NB cell lines tested, though effective inhibitory concentrations varied among cell lines. 17-AAG also suppressed the expression of VEGF. The cytotoxic effect of 17-AAG on tumor cells was diminished when co-cultured with bone marrow stromal cells suggesting a potential role for the microenvironment in tumor drug interactions. Findings from target modulation analysis as well as drug combination assays provide a frame-work to formulate effective protocols for the treatment of NB.
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PMID:Effects of Hsp90 inhibition in neuroblastoma: analysis of drug sensitivity, target modulation and the influence of bone marrow microenvironment. 1906 27

Most children with neuroblastoma presenting after infancy have metastatic, chemoresistant disease. Amplification of the MYCN proto-oncogene is a significant marker of these poor-prognosis neuroblastoma tumors. Recent studies suggest that MYCN may function in part by promoting angiogenesis via vascular endothelial growth factor (VEGF). VEGF blockade has been validated as a therapeutic strategy in adult cancers. In these studies, we asked whether inhibition of VEGF signaling via VEGFR2 blockade in established MYCN-amplified neuroblastoma xenografts would: 1) restrict tumor growth; 2) induce hypoxia; and 3) alter tumor vasculature. The MYCN-amplified neuroblastoma human cell line NGP was implanted intrarenally in athymic female mice. After 5 weeks, mice with established tumors were selected, a cohort euthanized to provide day 0 controls, and the rest assigned to receive biweekly injections of DC101 (anti-murine VEGFR2 antibody) or vehicle. DC101 treatment did not inhibit progressive tumor growth in established NGP xenografts. Although tumor vasculature was not significantly disrupted, a modest increase in tumor hypoxia was demonstrated by pimonidazole staining, and expression of a previously described hypoxia metagene was increased by gene set enrichment analysis (GSEA) in DC101-treated tumors. DC101 treatment elicited increased: 1) expression of VEGFR1 and its ligand placental growth factor; and 2) increased Notch activation in tumor vasculature concurrent with expression of the Notch ligand Jagged1. This result suggests that established MYCN-amplified neuroblastoma tumors are relatively VEGF-independent, and display the ability to rapidly up-regulate hypoxia-responsive alternative proangiogenic mechanisms that may stabilize vasculature when VEGF is deficient.
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PMID:Vascular endothelial growth factor blockade rapidly elicits alternative proangiogenic pathways in neuroblastoma. 1914 74

In this study we purposed an alternative method to study the angiogenic and invasive potential of neuroblastoma cell suspensions implanted on the chick embryo chorioallantoic membrane (CAM) surface. Neuroblastoma cells were seeded in Matrigel and thereafter the suspension was pipetted onto the CAM surface at day 8 of incubation inside a silicon ring previously loaded onto the CAM surface. Four days after implantation, the silicon ring was removed and the angiogenic and invasive response were studied morphologically at macroscopic and microscopic levels and by reverse transcriptase-polymerase chain reaction (RT-PCR) by using human and chicken primers for several angiogenic cytokines, namely vascular endothelial growth factor-A (VEGF-A), fibroblast growth factor-2 (FGF-2), angiopoietin-1 (ANG-1), hypoxia inducible factor-2alpha (HIF-2alpha), and for an endogenous angiostatic molecule, namely endostatin. Results showed that: (1) Neuroblastoma cells induced an angiogenic response in the CAM assay comparable to that induced by FGF-2; (2) neuroblastoma cells are packed inside Matrigel or are recognizable in the CAM mesenchyme; (3) Angiogenic activity of neuroblastoma cells is associated to an high expression of the transcripts of human VEGF-A, FGF-2, ANG-1 and HIF-2alpha and to a low expression in the transcript of a human endostatin while in the control specimens there is no expression of both angiogenic and angiostatic molecules; and (4) the expression of the transcripts of the same chicken angiogenesis stimulators and inhibitor is unmodified in treated and control specimens. Overall, these data indicate that neuroblastoma cells growth on the chick CAM express characteristics of the human disease. This experimental model could be employed for further research on human tumor progression and anti-angiogenic molecules screening.
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PMID:An alternative in vivo system for testing angiogenic potential of human neuroblastoma cells. 1915 May 83

Inhibitor of DNA-binding (Id) proteins prevent cell differentiation, promote growth and sustain tumour development. They do so by binding to E proteins and other transcription factors through the helix-loop-helix (HLH) domain, and inhibiting transcription. This makes HLH-mediated Id protein interactions an appealing therapeutic target. We have used the dominant interfering HLH dimerization mutant 13I to model the impact of Id inhibition in two human neuroblastoma cell lines: LA-N-5, similar to immature neuroblasts, and SH-EP, resembling more immature precursor cells. We have validated 13I as an Id inhibitor by showing that it selectively binds to Ids, impairs complex formation with RB, and relieves repression of E protein-activated transcription. Id inactivation by 13I enhances LA-N-5 neural features and causes SH-EP cells to acquire neuronal morphology, express neuronal proteins such as N-CAM and NF-160, proliferate more slowly, and become responsive to retinoic acid. Concomitantly, 13I augments the cell-cycle inhibitor p27(Kip1) and reduces the angiogenic factor vascular endothelial growth factor. These effects are Id specific, being counteracted by Id overexpression. Furthermore, 13I strongly impairs tumorigenic properties in agar colony formation and cell invasion assays. Targeting Id dimerization may therefore be effective for triggering differentiation and restraining neuroblastoma cell tumorigenicity.
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PMID:Targeting Id protein interactions by an engineered HLH domain induces human neuroblastoma cell differentiation. 1933 20

Neuroblastoma (NB) is one of the most common pediatric solid tumors originating from the neural crest lineage. Despite intensive treatment protocols including megatherapy with hematopoietic stem cell transplantation, the prognosis of NB patients remains poor. More effective therapeutics are required. High vascularity has been described as a feature of aggressive, widely disseminated NB. Our previous work demonstrated the overexpression of vascular endothelial growth factor (VEGF) in NB, and we showed that an anti-VEGF receptor (VEGFR-2) antibody could induce sustained NB tumor suppression and regression. Sunitinib is a kinase inhibitor targeting platelet-derived growth factor receptors and VEGFRs and, therefore, a promising antiangiogenic agent. In this study, we investigated the antitumor activity of sunitinib and its synergistic cytotoxicity with conventional (cyclophosphamide) and novel (rapamycin) therapies. Both NB cell lines and tumor-initiating cells from patient tumor samples were used in our in vitro and in vivo models for these drug testing. We show that sunitinib inhibits tumor cell proliferation and phosphorylation of VEGFRs. It also inhibits tumor growth, angiogenesis, and metastasis in tumor xenograft models. Low-dose sunitinib (20 mg/kg) demonstrates synergistic cytotoxicity with an mTOR inhibitor, rapamycin, which is more effective than the traditional chemotherapeutic drug, cyclophosphamide. These preclinical studies provide the evidence of antitumor activity of sunitinib both in the early stage of tumor formation and in the progressive metastatic disease. These studies also provide the framework for clinical trial of sunitinib, alone and in combination with conventional and novel therapies to increase efficacy and improve patient outcome in NB.
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PMID:In vivo antitumor and antimetastatic activity of sunitinib in preclinical neuroblastoma mouse model. 1941 27

The hypoxia inducible factor-1alpha (HIF1alpha) is a key regulator of oxygen homeostasis, modulating cell survival, and growth in cells exposed to hypoxia. In this study, neuroblastoma (NB) cells SH-SY5Y and SK-N-MC were employed to determine the mechanisms regulating adaptation to hypoxia. NB cells were cultured in a serum-free medium in the presence or absence of CoCl(2) (100 muM, hypoxia mimic) for up to 48 h. SH-SY5Y and SK-N-MC cell numbers were not affected by CoCl(2) treatment, while mitochondrial activity was reduced by approximately 50% in SH-SY5Y cells and by approximately 70% in SK-N-MC cells. Intracellular accumulation of HIF1alpha protein was detected as early as 30 min of post-hypoxia, followed by the increase of mRNA for vascular endothelial growth factor (VEGF) and nuclear accumulation of the ID1-2 transcription factors by 4 h. In hypoxic SH-SY5Y NB cells, real-time PCR analysis showed that the genes involved in maintenance of cell-cell and cell-matrix interactions (i.e. adenomatosis polyposis coli, E-cadherin, catenin, EphB2, fibronectin-1, HTATIP2, tissue inhibitor of metalloprotease-4) were down-regulated by up to 90%, while genes involved in enhancement of metastatic behavior (integrin a7b1, hepatocyte growth factor receptor, transforming growth factor-beta1, VEGF, kisspeptin, interleukin-1beta) were dramatically up-regulated above 200%. These changes were all consistent with the induction of epithelial-mesenchymal transition. We have thus demonstrated that NB cell adaptation to hypoxia, in addition to the modulation of HIF1alpha and VEGF expression and nuclear translocation of ID1 and ID2 transcription factors, involve in the activation of a gene expression program consistent with the pro-metastatic events. These processes are probably responsible for the NB cell transition from an adherent phenotype to a highly migratory, invasive and aggressive NB cell type.
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PMID:Activation of a prometastatic gene expression program in hypoxic neuroblastoma cells. 1942 15

Neuroblastoma is the childhood malignancy that mainly occurs in adrenal glands and is found also in the neck, chest, abdomen, and pelvis. New therapeutic strategies are urgently needed for successful treatment of this pediatric cancer. In this investigation, we examined efficacy of the retinoid N-(4-hydroxyphenyl) retinamide (4-HPR) and the isoflavonoid genistein (GST) alone and also in combination for controlling the growth of human malignant neuroblastoma SK-N-BE2 and SH-SY5Y xenografts in nude mice. Combination of 4-HPR and GST significantly reduced tumor volume in vivo due to overwhelming apoptosis in both neuroblastoma xenografts. Time-dependently, combination of 4-HPR and GST caused reduction in body weight, tumor weight, and tumor volume. Combination of 4-HPR and GST increased Bax:Bcl-2 ratio, mitochondrial release of Smac, downregulation of baculovirus inhibitor-of-apoptosis repeat containing (BIRC) proteins including BIRC-2 and BIRC-3, and activation of caspase-3 and apoptosis inducing factor (AIF). Further, downregulation of nuclear factor-kappa B (NF-kappaB), vascular endothelial growth factor (VEGF), and fibroblast growth factor 2 (FGF2) was also detected. In situ immunofluorescent labelings of tumor sections showed overexpression of calpain, caspase-12, and caspase-3, and also AIF in the course of apoptosis. Combination therapy increased apoptosis in the xenografts but did not induce kidney and liver toxicities in the animals. Results demonstrated that combination of 4-HPR and GST induced multiple molecular mechanisms for apoptosis and thus could be highly effective for inhibiting growth of malignant neuroblastoma in preclinical animal models.
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PMID:Combination of N-(4-hydroxyphenyl) retinamide and genistein increased apoptosis in neuroblastoma SK-N-BE2 and SH-SY5Y xenografts. 1954 Mar 15

Cyclooxygenase (COX)-2 is overexpressed in many human tumors including neuroblastoma (NB) and promotes tumor progression. We evaluated the antitumor effect of irinotecan (CPT-11) treatment combined with prolonged very low-dose administration of celecoxib, a selective COX-2 inhibitor, against three human NB xenografts, TNB9, TS-N-2nu, and TS-N-5nu. In addition, the effects of the celecoxib-combined treatment were examined on tumor cell proliferation, apoptosis, angiogenesis, and expression of vascular endothelial growth factor and apoptosis-related proteins in xenografts. Celecoxib administered daily at 5 mg/kg body weight/day could not prevent the growth of any of the NB xenografts. However, the combination of daily low-dose CPT-11 (5.9 mg/kg body weight/day) and simultaneous very low-dose celecoxib resulted in highly significant suppression of tumor growth in all three xenografts (P < 0.001) compared not only with low-dose CPT-11 therapy alone but also with the combination therapy of intermittent conventional-dose CPT-11 (59 mg/kg body weight) and celecoxib accompanied by decreased proliferation and increased induction of apoptosis in tumor cells. Induction of apoptosis by CPT-11 with and without celecoxib was associated with the up-regulation of Bax expression and the down-regulation of Bcl-2 expression. The enhanced antitumor effect of the combination of the two drugs against the NB xenografts might be partially COX-2-independent and was probably mediated through multiple factors including diminished expression of VEGF and activation of the caspase-dependent mitochondrial apoptosis pathway. These findings demonstrate that prolonged low-dose CPT-11 treatment combined with very low-dose celecoxib shows promising antitumor activity through the blockage of multiple critical targets related to NB tumor cell survival and proliferation.
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PMID:Prolonged low-dose administration of the cyclooxygenase-2 inhibitor celecoxib enhances the antitumor activity of irinotecan against neuroblastoma xenografts. 1967 86

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