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

In vitro and in vivo models have been developed that have allowed for delineation of mechanisms of multiple myeloma (MM) cell homing to bone marrow (BM); tumor cell adhesion to extracellular matrix proteins and BM stromal cells; and cytokine-mediated growth, survival, drug resistance, and migration within the BM milieu. Delineation of the signaling cascades mediating these sequelae has identified multiple novel therapeutic targets in the tumor cell and its BM microenvironment. Importantly, novel therapies targeting the tumor cell and the BM, as well as those targeting the tumor cell or BM alone, can overcome the growth, survival, conventional drug resistance, and migration of MM cells bound to BM using both in vitro and in vivo severe combined immunodeficiency mouse models of human MM. These studies have translated rapidly from the bench to the bedside in derived clinical trials, and have already led to the United States Food and Drug Administration approval of the novel proteasome inhibitor bortezomib for treatment of relapsed/refractory MM. Novel agents will need to be combined to enhance cytotoxicity, avoid development of drug resistance, and allow for use of lower doses in combination therapies. Genomics, proteomics, and cell signaling studies have helped to identify in vivo mechanisms of sensitivity versus resistance to novel therapies, as well as aiding in the rational application of combination therapies. These studies have therefore provided the framework for a new treatment paradigm targeting the MM cell in its BM milieu to overcome drug resistance and improve patient outcome in MM.
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PMID:Identification and validation of novel therapeutic targets for multiple myeloma. 1615 18

This study was aimed to evaluate the in vivo antitumor effect of genetically modified myeloma cell vaccine on human myeloma xenografts implanted into nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mice. Human immune system was established in NOD/SCID mice by intraperitoneal injection of human peripheral blood lymphocytes (PBLs). After being inoculated subcutaneously with irradiated myeloma cell line sko-007, adenovirally transferred with GFP or p53, granulocyte-macrophage colony-stimulating factor (GM-CSF) and B7-1 genes, huPBL-NOD/SCID mice were challenged by subcutaneous injection of non-transferred sko-007 cells. The results indicated that Ad-p53/GM-CSF/B7-1-infected sko-007 cell vaccination significantly reduced local tumor growth compared with controls. Histopathological and immunohistochemical analysis showed that tumor tissues increasingly displayed diffuse necrosis, mainly caused by apoptosis, accompanied with significant fibroplasias and blood vessel hyperplasia, and human T cells infiltrated into the tumor tissues. It is concluded that transgenic p53, GM-CSF and B7-1 expression produces an immune response against myeloma cells and may be of therapeutic value for multiple myeloma in human being.
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PMID:Genetically modified myeloma cell vaccine inducing antitumor immune response in vivo. 1658 92

Pleiotrophin (PTN) is an important developmental cytokine that is highly expressed during embryogenesis but shows very limited expression in adult tissues, where it is largely restricted to the brain. High PTN serum levels are associated with a variety of solid tumors. We recently showed that patients with multiple myeloma (MM) also have elevated serum levels of this protein and the amount of PTN correlated with the patients' disease status and response to treatment. In this study, we demonstrate that MM cell lines and the malignant cells from MM patients' bone marrow produced PTN and secreted PTN protein into the supernatants during short-term culture. Moreover, Ptn gene expression correlated with the patients' disease status. Inhibition of PTN with a polyclonal anti-PTN antibody reduced growth and enhanced apoptosis of MM cell lines and freshly isolated bone marrow tumor cells from MM patients in vitro. Importantly, this antibody also markedly suppressed the growth of MM in vivo using a severe combined immunodeficiency (SCID)-hu murine model. This represents the first study showing the importance of PTN in the growth of any hematological disorder. Because the expression of this protein is very limited in normal adult tissues, PTN may represent a new target for the treatment of MM.
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PMID:Pleiotrophin is highly expressed by myeloma cells and promotes myeloma tumor growth. 1736 88

Bortezomib, an inhibitor of the 26S proteasome, is currently approved for treatment of multiple myeloma and is being studied for therapy of non-Hodgkin's lymphoma. We found that Epstein-Barr virus (EBV)-positive B cells with type III latency were more susceptible to killing by bortezomib than those with type I latency. Bortezomib induced apoptosis of EBV lymphoblastoid cell lines (LCLs) by inducing cleavage of caspases 8 and 9; apoptosis was inhibited by pretreatment with a pan-caspase inhibitor. Bortezomib reduced the levels of the p50 and p65 components of the canonical NF-kappaB pathway and reduced the level of p52 in the noncanonical NF-kappaB pathway, which is induced by EBV LMP1. Bortezomib inhibited expression of cIAP-1, cIAP-2, and XIAP, which are regulated by NF-kappaB and function as inhibitors of apoptosis. Bortezomib did not inhibit expression of several other antiapoptotic proteins, including Bcl-2 and Bcl-XL. Finally, bortezomib significantly prolonged the survival of severe combined immunodeficiency mice inoculated with LCLs. These findings suggest that bortezomib may represent a novel strategy for the treatment of certain EBV-associated lymphomas.
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PMID:Bortezomib induces apoptosis of Epstein-Barr virus (EBV)-transformed B cells and prolongs survival of mice inoculated with EBV-transformed B cells. 1762 72

Previous studies have demonstrated the effects of brain-derived neurotrophic factor (BDNF) on promoting proliferation of multiple myeloma (MM) cells and inducing angiogenesis in MM in vitro. This study was aimed to further explore whether BDNF/TrkB pathway is a potential therapeutic target in MM, and to elucidate the advantages and disadvantages of two ways developed for human myeloma xenograft in animal models. The models of xenograft tumors were established in the non-obese diabetic/severe combined immunodeficiency (NOD/SCID) mice by subcutaneous or intravenous injection of human myeloma cell line RPMI8226. Mice were monitored daily for life state, and the volume of subcutaneous tumors were measured after inoculation. 3 weeks after inoculation, red blood cell counts, BDNF level in plasma, human lambda light chain and calcium level in serum of NOD/SCID were detected every two weeks. The histological and cytological examinations were performed to observe pathological features of tumors. Using flow cytometry to observe the expression of human CD38+ cell in murine blood and bone marrow. The changes of bone density and skeletal lesions were detected by computer radiography. The results showed that the subcutaneously injected animal model showed a high growth efficiency of RPMI8226 subcutaneous tumors (5/5) and several pathological features of plasmacytomas. There were neither obvious increase in lambda light chain and calcium levels, nor spread of human MM cells to murine bone marrow and no radiological evidence of skeletal lesions. The intravenously injected animal model had relative low efficiency for growth of tumors (4/7) but MM cells could engraft and proliferate in murine bone marrow. The human lambda light chain could be detected in serum as early as 3 weeks after inoculation. Myeloma-bearing mice had high level of lambda light chain and high calcium in serum and resorption of the murine bone. Furthermore, the concentrations of BDNF were increased with the tumor growth in both models with (73 +/- 11) pg/ml and (105 +/- 18) pg/ml in plasma respectively at 9 weeks after inoculation. It is concluded that two appropriate MM xenograft NOD/SCID animal models were established, both of which show high BDNF levels in the plasma. Therefore, two valuable in vivo systems to explore novel therapeutic target (BDNF/TrkB) in MM have been set up successfully.
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PMID:[Establishment of multiple myeloma mouse models expressing brain derived neurotrophic factor]. 1795 71

The interaction between multiple myeloma (MM) cells and the bone marrow (BM) microenvironment induces proliferation and survival of MM cells, as well as osteoclastogenesis. This study investigated the therapeutic potential of novel p38 mitogen-activated protein kinase (p38MAPK) inhibitor LY2228820 (LY) in MM. Although cytotoxicity against MM cell lines was modest, LY significantly enhanced the toxicity of bortezomib by down-regulating bortezomib-induced heat shock protein 27 phosphorylation. LY inhibited interleukin-6 secretion from long term cultured-BM stromal cells and BM mononuclear cells (BMMNCs) derived from MM patients in remission. LY also inhibited macrophage inflammatory protein-1alpha secretion from patient MM cells and BMMNCs as well as normal CD14 positive osteoclast precursor cells. Moreover, LY significantly inhibited in vitro osteoclastogenesis from CD14 positive cells induced by macrophage-colony stimulating factor and soluble receptor activator of nuclear factor-kappaB ligand. Finally, LY also inhibited in vivo osteoclatogenesis in a severe combined immunodeficiency mouse model of human MM. These results suggest that LY represents a promising novel targeted approach to improve MM patient outcome both by enhancing the effect of bortezomib and by reducing osteoskeletal events.
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PMID:p38 mitogen-activated protein kinase inhibitor LY2228820 enhances bortezomib-induced cytotoxicity and inhibits osteoclastogenesis in multiple myeloma; therapeutic implications. 1839 45

This study was aimed to further explore whether brain derived neurotrophic factor (BDNF) pathway is a potential therapeutic target in multiple myeloma (MM) and whether anti-BDNF monoclonal antibody can prevent the development of this disease. The in vivo antitumor effect of anti-BDNF monoclonal antibody (McAb) on a human myeloma xenograft animal model was evaluated. The model of xenograft tumors was established in the nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mice by subcutaneous injection of human myeloma cell line RPMI8226. The antibodies were injected intraperitoneally at a dose of 20 microg/mouse at day 1, 2, 3 after inoculation or at a dose of 100 microg/mouse once a week after tumors were detected. The microvascular densities in tumors were analyzed by immunohistochemistry study. The effect of anti-BDNF McAb on the proliferation of RPMI8226 cells in vitro and on endothelial cells network formation in the co-culture system were determined by using a (3)H-thymidine incorporation assay and a Matrigel network formation assay, respectively. The results showed that multiple injections of anti-BDNF McAb reduced the tumor size, decreased the microvascular density and significantly prolonged tumor-free time and survival time. Moreover, the proliferation of RPMI8226 cells was inhibited in vitro by anti-BDNF McAb, but not by the control IgG. Anti-BDNF McAb also inhibited RPMI8226-induced network formation in endothelial cells in vitro. It is concluded that anti-BDNF monoclonal antibody can inhibit cell growth and angiogenesis in subcutaneous plasmacytoma.
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PMID:Antitumor effect of anti-brain derived neurotrophic factor monoclonal antibody in human multiple myeloma xenograft animal model. 1892 97

Valproic acid (VPA) is a well-tolerated anticonvulsant that exerts anti-tumour activity as a histone deacetylase inhibitor. This study investigated the in vitro and in vivo activity of VPA against multiple myeloma (MM) cells. In vitro exposure of interleukin-6-dependent or -independent MM cells to VPA inhibited cell proliferation in a time- and dose-dependent manner and induced apoptosis. In a cohort of severe combined immunodeficiency mice bearing human MM xenografts, VPA induced tumour growth inhibition and survival advantage in treated animals versus controls. Flow cytometric analysis performed on MM cells from excised tumours showed increase of G(0)-G(1) and a decreased G(2)/M- and S-phase following VPA treatment, indicating in vivo effects of VPA on cell cycle regulation. Gene expression profiling of MM cells exposed to VPA showed downregulation of genes involved in cell cycle progression, DNA replication and transcription, as well as upregulation of genes implicated in apoptosis and chemokine pathways. Pathfinder analysis of gene array data identified cell growth, cell cycle, cell death, as well as DNA replication and repair as the most important signalling networks modulated by VPA. Taken together, our data provide the preclinical rationale for VPA clinical evaluation as a single agent or in combination, to improve patient outcome in MM.
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PMID:In vivo anti-myeloma activity and modulation of gene expression profile induced by valproic acid, a histone deacetylase inhibitor. 1898 88

Decreased activity of osteoblasts (OBs) contributes to osteolytic lesions in multiple myeloma (MM). The production of the soluble Wnt inhibitor Dickkopf-1 (DKK1) by MM cells inhibits OB activity, and its serum level correlates with focal bone lesions in MM. Therefore, we have evaluated bone anabolic effects of a DKK1 neutralizing antibody (BHQ880) in MM. In vitro BHQ880 increased OB differentiation, neutralized the negative effect of MM cells on osteoblastogenesis, and reduced IL-6 secretion. In a severe combined immunodeficiency (SCID)-hu murine model of human MM, BHQ880 treatment led to a significant increase in OB number, serum human osteocalcin level, and trabecular bone. Although BHQ880 had no direct effect on MM cell growth, it significantly inhibited growth of MM cells in the presence of bone marrow stromal cells (BMSCs) in vitro. This effect was associated with inhibition of BMSC/MM cell adhesion and production of IL-6. In addition, BHQ880 up-regulated beta-catenin level while down-regulating nuclear factor-kappaB (NF-kappaB) activity in BMSC. Interestingly, we also observed in vivo inhibition of MM cell growth by BHQ880 treatment in the SCID-hu murine model. These results confirm DKK1 as an important therapeutic target in myeloma and provide the rationale for clinical evaluation of BHQ880 to improve bone disease and to inhibit MM growth.
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PMID:Anti-DKK1 mAb (BHQ880) as a potential therapeutic agent for multiple myeloma. 1941 13

Specific genetic alterations in multiple myeloma (MM) may cause more aggressive diseases. Paired gene array analysis on 51 samples showed that retinoic acid (RA) receptor alpha (RARalpha) expression significantly increased at relapse compared with diagnosis. RARalpha encodes 2 major isoforms: RARalpha1 and RARalpha2. In this study, we examined the function of RARalpha2 in MM. Reverse transcription-polymerase chain reaction (RT-PCR) revealed ubiquitous RARalpha1 expression in MM cells, but RARalpha2 was expressed in 26 (32%) of 80 newly diagnosed patients and 10 (28%) of 36 MM cell lines. Patients with RARalpha2 expression had a significantly shorter overall survival on identical treatments. The presence of RARalpha2 remained significant on multivariate analysis. Knockdown of RARalpha2 but not RARalpha1 induced significant MM cell death and growth inhibition, and overexpressing RARalpha2 activated STAT3 and mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) signaling pathways. Interestingly, all-trans retinoic acid (ATRA) treatment induced potent cell death and growth inhibition in RARalpha2(+) but not RARalpha2(-) MM cells; overexpressing RARalpha2 in RARalpha2-deficient MM cells restored sensitivity to ATRA. Furthermore, ATRA treatment significantly inhibited the growth of RARalpha2-overexpressing MM tumors in severe combined immunodeficiency (SCID) mouse model. These findings provide a rationale for RA-based therapy in aggressive RARalpha2(+) MM.
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PMID:RARalpha2 expression is associated with disease progression and plays a crucial role in efficacy of ATRA treatment in myeloma. 1945 57


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