Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0026764 (multiple myeloma)
 36,148 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Bortezomib (PS-341), a proteasome inhibitor, has been examined clinically for the treatment of multiple myeloma and several solid tumors. Bortezomib directly induces tumor cell death and has also been reported to inhibit tumor adaptation to hypoxia by functionally inhibiting hypoxia-inducible factor-1alpha (HIF-1alpha). However, the mechanism underlying HIF-1 inhibition by bortezomib remains obscure. In the present study, we demonstrated that bortezomib attenuated the hypoxic induction of erythropoietin and vascular endothelial growth factor at subnanomolar concentrations in multiple myeloma and liver cancer cell lines, regardless of cytotoxic concentrations of bortezomib. Bortezomib repressed HIF-1alpha activity by inhibiting the recruitment of p300 coactivator. Specifically, bortezomib targeted HIF-1alpha C-terminal transactivation domain (CAD) but not the CAD lacking Asn803, which is a hydroxylation site by the factor inhibiting HIF-1 (FIH). Accordingly, this effect of bortezomib on CAD was augmented by FIH expression and abolished by FIH knock-down. Furthermore, bortezomib stimulated the interaction between CAD and FIH under hypoxic conditions, and FIH inhibition reversed the suppressions of erythropoietin and vascular endothelial growth factor by bortezomib. We propose that the mechanism underlying the inhibitory effects of bortezomib on tumor angiogenesis and hypoxic adaptation involves the repression of HIF-1alpha transcriptional activity by reinforcing the FIH-mediated inhibition of p300 recruitment.
 ...
PMID:Bortezomib inhibits tumor adaptation to hypoxia by stimulating the FIH-mediated repression of hypoxia-inducible factor-1. 1846 14

In human adults, new blood vessels may form via endothelial sprouting from pre-existing endothelial cells/angioblasts (angiogenesis) or via the recruitment of circulating endothelial progenitor cells (EPCs) (vasculogenesis). EPCs are a population of bone marrow-derived cells able to differentiate into mature endothelial cells and participating in the formation of new blood vessels. The molecular phenotype of EPCs and processes leading to their mobilization from bone marrow and homing to neovascularization sites remain unclear. There is still debate regarding methods for their quantification and isolation. In the field of rheumatology, EPCs have been studied in multiple myeloma and inflammatory rheumatic disorders. In myeloma, data suggest that EPCs could be reliable biomarkers of tumor angiogenesis, growth and antiangiogenic therapy efficacy. Recent studies suggest that EPCs are involved in synovial vascularization, and may contribute to the increased cardiovascular morbidity and mortality in rheumatoid arthritis, known features of this disease. In systemic lupus erythematosus, preliminary data suggest that EPCs are decreased. Results available in systemic sclerosis are consistent with the hypothesis that EPCs are recruited during active disease; however, their levels may be depleted as the disease progresses and under chronic ischemic conditions. EPCs are important in vasculogenesis, and may be involved in other systemic features of inflammatory rheumatic disorders.
 ...
PMID:Endothelial progenitor cells and rheumatic disorders. 1831 71

The chick embryo chorioallantoic membrane (CAM) is commonly used as an experimental in vivo assay to study both angiogenesis and antiangiogenesis in response to tissues, cells or soluble factors. This article summarizes literature data about the use of the CAM in the study of tumor angiogenesis and particularly our experimental data concerning the study of angiogenesis in multiple myeloma and in neuroblastoma.
 ...
PMID:The chick embryo chorioallantoic membrane in the study of tumor angiogenesis. 1851 17

The chick embryo chorioallantoic membrane (CAM) is an extraembryonic membrane mediating gas and nutrient exchanges until hatching. Since it has a dense capillary network, it has been commonly used in vivo to study both angiogenesis and antiangiogenesis in response to normal tissues and cells, to tumor bioptic specimens and cells, or to soluble factors. During the last 8 years, this assay has been used in over 550 published works. This chapter summarizes current knowledge about the embryological origin of the CAM, morphology of its blood and lymphatic vessels, the use of CAM in the study of tumor angiogenesis and metastasis, angiogenic and antiangiogenic substances. The angiogenic response of CAM to multiple myeloma and neuroblastoma cells and bioptic specimens and their responses to antiangiogenic molecules and the role played by fibroblast growth factor-2 in CAM vascularization have been analyzed in detail. Finally, advantages and limitations of CAM as an experimental model to study angiogenesis and antiangiogenesis are discussed.
 ...
PMID:Chick embryo chorioallantoic membrane as a useful tool to study angiogenesis. 1908 37

Myeloma tumors are characterized by high expression of syndecan-1 (CD138), a heparan sulfate proteoglycan present on the myeloma cell surface and shed into the tumor microenvironment. High levels of shed syndecan-1 in the serum of patients are an indicator of poor prognosis, and numerous studies have implicated syndecan-1 in promoting the growth and progression of this cancer. In the present study we directly addressed the role of syndecan-1 in myeloma by stable knockdown of its expression using RNA interference. Knockdown cells that were negative for syndecan-1 expression became apoptotic and failed to grow in vitro. Knockdown cells expressing syndecan-1 at approximately 28% or approximately 14% of normal levels survived and grew well in vitro but formed fewer and much smaller subcutaneous tumors in mice compared with tumors formed by cells expressing normal levels of syndecan-1. When injected intravenously into mice (experimental metastasis model), knockdown cells formed very few metastases as compared with controls. This indicates that syndecan-1 may be required for the establishment of multi-focal metastasis, a hallmark of this cancer. One mechanism of syndecan-1 action occurs via stimulation of tumor angiogenesis because tumors formed by knockdown cells exhibited diminished levels of vascular endothelial growth factor and impaired development of blood vessels. Together, these data indicate that the effects of syndecan-1 on myeloma survival, growth, and dissemination are due, at least in part, to its positive regulation of tumor-host interactions that generate an environment capable of sustaining robust tumor growth.
 ...
PMID:Syndecan-1 is required for robust growth, vascularization, and metastasis of myeloma tumors in vivo. 1959 56

Abnormal activation of hypoxia-inducible factor-1 (HIF-1), one of the most important transcription factors for the adaptation of cells to hypoxia, is frequently observed in numerous types of solid tumors. Dysregulation of HIF-1 induces tumor angiogenesis and enhances the expression of anti-apoptotic proteins and glycolysis-associated enzymes in cancer cells, which in turn leads to the promotion of tumor growth. In the present study, we examined the pathophysiologic role of HIF-1 in multiple myeloma. Furthermore, we explored the possibility that HIF-1 may be a molecular target for myeloma therapy. We identified constitutive expression of the hypoxia-inducible factor-1 alpha (HIF-1alpha)-subunit in established myeloma cell lines and in primary myeloma cells. Treatment with insulin-like growth factor-1 (IGF-1) significantly increased HIF-1alpha expression through activation of the AKT and mitogen-activated protein kinase signaling pathways. Inhibition of HIF-1 function either by echinomycin, a specific HIF-1 inhibitor, or a siRNA against HIF-1alpha resulted in enhanced sensitivity to melphalan in myeloma cells. This inhibition of HIF-1 also reversed the protective effect of IGF-1 on melphalan-induced apoptosis. Inhibition of HIF-1 drastically reduced both basal and IGF-1-induced expression of survivin, one of the most important anti-apoptotic proteins in myeloma cells. We conclude that HIF-1 inhibition may be an attractive therapeutic strategy for multiple myeloma.
 ...
PMID:Inhibition of hypoxia-inducible factor-1 function enhances the sensitivity of multiple myeloma cells to melphalan. 1967 32

Heparanase enhances shedding of syndecan-1 (CD138), and high levels of heparanase and shed syndecan-1 in the tumor microenvironment are associated with elevated angiogenesis and poor prognosis in myeloma and other cancers. To explore how the heparanase/syndecan-1 axis regulates angiogenesis, we used myeloma cells expressing either high or low levels of heparanase and examined their impact on endothelial cell invasion and angiogenesis. Medium conditioned by heparanase-high cells significantly stimulated endothelial invasion in vitro compared with medium from heparanase-low cells. The stimulatory activity was traced to elevated levels of vascular endothelial growth factor (VEGF) and syndecan-1 in the medium. We discovered that the heparan sulfate chains of syndecan-1 captured VEGF and also attached the syndecan-1/VEGF complex to the extracellular matrix where it then stimulated endothelial invasion. In addition to its heparan sulfate chains, the core protein of syndecan-1 was also required because endothelial invasion was blocked by addition of synstatin, a peptide mimic of the integrin activating region present on the syndecan-1 core protein. These results reveal a novel mechanistic pathway driven by heparanase expression in myeloma cells whereby elevated levels of VEGF and shed syndecan-1 form matrix-anchored complexes that together activate integrin and VEGF receptors on adjacent endothelial cells thereby stimulating tumor angiogenesis.
 ...
PMID:Heparanase-enhanced shedding of syndecan-1 by myeloma cells promotes endothelial invasion and angiogenesis. 2009 82

The formation of a new vascular network by angiogenesis is a key driver in tumor growth and metastasis, making this an attractive therapeutic target. Different strategies are being developed to either prevent tumor angiogenesis or disrupt the tumor vasculature already in place. In this in vitro study, we investigated the antivascular properties of ENMD-1198, a new anticancer drug currently in clinical trials. ENMD-1198 is a new analogue of 2-methoxyestradiol, a microtubule-targeting agent that has shown promising results in the treatment of multiple myeloma and hormone-refractory prostate cancer. Using both bone marrow-derived and dermal microvascular endothelial cell lines, we analyzed the effect of ENMD-1198 on the different functions of endothelial cells involved in angiogenesis. In both cell lines, ENMD-1198 was more potent than 2-methoxyestradiol at inhibiting endothelial cell proliferation, motility, migration, and morphogenesis. In addition, ENMD-1198 induced a significant decrease in vascular endothelial growth factor receptor-2 protein expression in endothelial cells. Furthermore, videomicroscopy experiments showed that ENMD-1198 was able to completely disrupt preformed vascular structures within 2 hours. This vascular-disrupting activity was associated with extensive depolymerization of the microtubule network and accumulation of actin stress fibers and large focal adhesions in vascular endothelial cells. Collectively, our results show that this new compound displays potent antivascular properties, and this study provides important insights into the mechanism of action of this promising new anticancer drug.
 ...
PMID:ENMD-1198, a new analogue of 2-methoxyestradiol, displays both antiangiogenic and vascular-disrupting properties. 2044 4

The fibroblast growth factor receptors (FGFR) are tyrosine kinases that are present in many types of endothelial and tumor cells and play an important role in tumor cell growth, survival, and migration as well as in maintaining tumor angiogenesis. Overexpression of FGFRs or aberrant regulation of their activities has been implicated in many forms of human malignancies. Therefore, targeting FGFRs represents an attractive strategy for development of cancer treatment options by simultaneously inhibiting tumor cell growth, survival, and migration as well as tumor angiogenesis. Here, we describe a potent, selective, small-molecule FGFR inhibitor, (R)-(E)-2-(4-(2-(5-(1-(3,5-Dichloropyridin-4-yl)ethoxy)-1H-indazol-3yl)vinyl)-1H-pyrazol-1-yl)ethanol, designated as LY2874455. This molecule is active against all 4 FGFRs, with a similar potency in biochemical assays. It exhibits a potent activity against FGF/FGFR-mediated signaling in several cancer cell lines and shows an excellent broad spectrum of antitumor activity in several tumor xenograft models representing the major FGF/FGFR relevant tumor histologies including lung, gastric, and bladder cancers and multiple myeloma, and with a well-defined pharmacokinetic/pharmacodynamic relationship. LY2874455 also exhibits a 6- to 9-fold in vitro and in vivo selectivity on inhibition of FGF- over VEGF-mediated target signaling in mice. Furthermore, LY2874455 did not show VEGF receptor 2-mediated toxicities such as hypertension at efficacious doses. Currently, this molecule is being evaluated for its potential use in the clinic.
 ...
PMID:A novel, selective inhibitor of fibroblast growth factor receptors that shows a potent broad spectrum of antitumor activity in several tumor xenograft models. 2190 Jun 93

Research on the formation of new blood vessels (angiogenesis) in general and vascular endothelial growth factor (VEGF) in particular is a major focus in biomedicine and has led to the clinical approval of the monoclonal anti- VEGF antibody bevazicumab; and the second-generation multitargeted receptor kinase inhibitors (RTKIs) sorafenib, sunitinib, and pazopanib. Although these agents show significant preclinical and clinical anti-cancer activity, they prolong overall survival of cancer patients for only months, followed by a restoration of tumor growth and progression. Therefore, there is a clear need to increase our understanding of tumor angiogenesis and the development of resistance. In this review we discuss up-to-date knowledge on mechanisms of tumor angiogenesis, and summarize preclinical and clinical data on existing and potential future anti-angiogenic agents and treatment strategies for Multiple Myeloma (MM) and other hematologic and solid malignancies.
 ...
PMID:Emerging therapies targeting tumor vasculature in multiple myeloma and other hematologic and solid malignancies. 2193 9


<< Previous 1 2 3 4 Next >>