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Query: UMLS:C0026764 (multiple myeloma)
 36,148 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The mechanism of antitumor effect of monoclonal antibodies (mAbs) is not fully understood. Here we show that coating myeloma cells with anti-syndecan-1 antibody promotes cross-presentation of cellular antigens by dendritic cells (DCs) to autologous T cells from healthy donors. The tumor cells treated with anti-syndecan-1 or isotype-matched control antibody were fed to HLA-mismatched monocyte-derived immature DCs. Tumor cell-loaded mature DCs induced a strong CD8(+) T cell response that was specific for the cancer-testis (C-T) antigens expressed in the tumor. The CD8(+) T cells killed peptide-pulsed targets, as well as myeloma tumor cells. Importantly, mAbs-coated tumor-loaded DCs were consistently superior to DCs loaded with peptides or dying cells for eliciting tumor-specific killer T cells. This enhanced cross-presentation was not due to enhanced tumor cell uptake or to DC maturation. When mixtures of NY-Eso-1-positive and -negative myeloma cells were captured by DCs, the anti-syndecan-1 antibody had to be on the NY-Eso-1-positive cells to elicit NY-Eso-1-specific response. Cross-presentation was inhibited by pretreatment of DCs with Fc gamma receptor blocking antibodies. Targeting of mAb-coated tumors to DCs may contribute to the efficacy of tumor-reactive mAb and offers a new strategy for immunotherapy.
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PMID:Antitumor monoclonal antibodies enhance cross-presentation ofcCellular antigens and the generation of myeloma-specific killer T cells by dendritic cells. 1178 74

Heparan sulfate proteoglycans (HSPGs) play a crucial role in growth regulation by assembling signaling complexes and presenting growth factors to their cognate receptors. Within the immune system, expression of the HSPG syndecan-1 (CD138) is characteristic of terminally differentiated B cells, ie, plasma cells, and their malignant counterpart, multiple myeloma (MM). This study explored the hypothesis that syndecan-1 might promote growth factor signaling and tumor growth in MM. For this purpose, the interaction was studied between syndecan-1 and hepatocyte growth factor (HGF), a putative paracrine and autocrine regulator of MM growth. The study demonstrates that syndecan-1 is capable of binding HGF and that this growth factor is indeed a potent stimulator of MM survival and proliferation. Importantly, the interaction of HGF with heparan sulfate moieties on syndecan-1 strongly promotes HGF-mediated signaling, resulting in enhanced activation of Met, the receptor tyrosine kinase for HGF. Moreover, HGF binding to syndecan-1 promotes activation of the phosphatidylinositol 3-kinase/protein kinase B and RAS/mitogen-activated protein kinase pathways, signaling routes that have been implicated in the regulation of cell survival and proliferation, respectively. These results identify syndecan-1 as a functional coreceptor for HGF that promotes HGF/Met signaling in MM cells, thus suggesting a novel function for syndecan-1 in MM tumorigenesis.
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PMID:Cell surface proteoglycan syndecan-1 mediates hepatocyte growth factor binding and promotes Met signaling in multiple myeloma. 1183 Apr 93

Syndecans are heparan sulfate-bearing proteoglycans that are found on the surface of most cells. Syndecan-1 is expressed predominantly on epithelia, but is also present on pre-B cells and plasma cells. The syndecans act to bind various effector molecules via their heparan sulfate chains, including both soluble and insoluble molecules within the extracellular milieu. These interactions promote cell adhesion to extracellular matrix and to adjacent cells. In addition, the syndecans can bind to and affect the biological activity of a number of heparin-binding growth factors. Thus, syndecan-1 can play a dramatic role in regulating cell behavior. In this review we discuss the expression of syndecan-1 on malignant B lymphoid cells as well as specific structure-function relationships of the molecule. Emphasis is placed on the important role that syndecan-1 has in regulating the growth of B lymphoid malignancies, particularly multiple myeloma.
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PMID:Syndecan-1 in B lymphoid malignancies. 1190 37

Syndecan-1 (CD138) is a transmembrane heparan sulfate-bearing proteoglycan expressed by most myeloma plasma cells that regulates adhesion, migration, and growth factor activity. In patients with myeloma, shed syndecan-1 accumulates in the bone marrow, and high levels of syndecan-1 in the serum are an indicator of poor prognosis. To test the effect of soluble syndecan-1 on tumor cell growth and dissemination, ARH-77 B-lymphoid cells were engineered to produce a soluble form of syndecan-1. Controls included vector only (neo)-transfected cells and cells transfected with full-length syndecan-1 complementary DNA that codes for the cell surface form of syndecan-1. Assays reveal that all 3 transfectants have similar growth rates in vitro, but cells expressing soluble syndecan-1 are hyperinvasive in collagen gels relative to controls. When injected into the marrow of human bones that were implanted in severe combined immunodeficient mice, tumors formed by cells expressing soluble syndecan-1 grow faster than tumors formed by neo-transfected cells or by cells expressing cell surface syndecan-1. In addition, cells bearing cell surface syndecan-1 exhibit a diminished capacity to establish tumors within the mice as compared with both neo- and soluble syndecan-1-transfected cells. Tumor cell dissemination to a contralateral human bone is detected significantly more often in the tumors producing soluble syndecan-1 than in controls. Thus, high levels of soluble syndecan-1 present in patients with myeloma may contribute directly to the growth and dissemination of the malignant cells and thus to poor prognosis.
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PMID:Soluble syndecan-1 promotes growth of myeloma tumors in vivo. 1209 55

The soluble form of the syndecan-1 heparan sulfate proteoglycan acts as a tumor suppressor molecule that inhibits growth and induces apoptosis of some cancer cell lines in vitro. Analogs of syndecan-1 were produced by carbodiimide (EDAC) conjugation of glycosaminoglycan (GAG) chains to a protein scaffold, thereby generating synthetic proteoglycans that were evaluated for anticancer properties. Surprisingly, when analyzing activities of the controls, we discovered that EDAC modified GAG chains inhibit myeloma cell viability even in the absence of protein. Here, we describe the production and the activities of these novel molecules called neoglycans. The GAG chains heparin and chondroitin sulfate (CS) were exposed to EDAC to generate the neoglycans neoheparin and neoCS, respectively. Heparin and CS in the absence of EDAC modification have no effect or a slight growth promoting effect on cancer and normal cell lines. However, neoheparin and neoCS substantially reduce cell viability by induction of apoptosis of myeloma and breast cancer cells in vitro. NeoCS when injected directly into breast tumors growing in nude mice reduces or abolishes their growth without causing apparent toxicity to the adjacent normal tissue. The neoglycans need not be continuously present in cell cultures because a short pulse exposure is sufficient to reduce cell viability. NeoCS fractions purified by size exclusion chromatography reduce myeloma cell viability, confirming the specificity of neoglycan activity. Collectively, the results of this study demonstrate the anticancer activities of this new class of GAG chain-based molecules and provide the foundation for future development of neoglycans as novel therapeutic agents.
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PMID:Neoglycans, carbodiimide-modified glycosaminoglycans: a new class of anticancer agents that inhibit cancer cell proliferation and induce apoptosis. 1209 81

We have created a molecular resource of genes expressed in primary malignant plasma cells using a combination of cDNA library construction, 5' end single-pass sequencing, bioinformatics, and microarray analysis. In total, we identified 9732 nonredundant expressed genes. This dataset is available as the Myeloma Gene Index (www.uhnres.utoronto.ca/akstewart_lab).Predictably, the sequenced profile of myeloma cDNAs mirrored the known function of immunoglobulin-producing, high-respiratory rate, low-cycling, terminally differentiated plasma cells. Nevertheless, approximately 10% of myeloma-expressed sequences matched only entries in the database of Expressed Sequence Tags (dbEST) or the high-throughput genomic sequence (htgs) database. Numerous novel genes of potential biologic significance were identified. We therefore spotted 4300 sequenced cDNAs on glass slides creating a myeloma-enriched microarray. Several of the most highly expressed genes identified by sequencing, such as a novel putative disulfide isomerase (MGC3178), tumor rejection antigen TRA1, heat shock 70-kDa protein 5, and annexin A2, were also differentially expressed between myeloma and B lymphoma cell lines using this myeloma-enriched microarray. Furthermore, a defined subset of 34 up-regulated and 18 down-regulated genes on the array were able to differentiate myeloma from nonmyeloma cell lines. These not only include genes involved in B-cell biology such as syndecan, BCMA, PIM2, MUM1/IRF4, and XBP1, but also novel uncharacterized genes matching sequences only in the public databases. In summary, our expressed gene catalog and myeloma-enriched microarray contains numerous genes of unknown function and may complement other commercially available arrays in defining the molecular portrait of this hematopoietic malignancy. GenBank Accession numbers include BF169967-BF176369, BF185966-BF185969, and BF177280-BF177455.
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PMID:A molecular compendium of genes expressed in multiple myeloma. 1220 Mar 83

Syndecan-1 (CD138) mediates myeloma cell adhesion, and loss of syndecan-1 from the cell surface may contribute to myeloma cell proliferation and dissemination and influence the prognosis in patients with multiple myeloma (MM). In order to test this hypothesis, we have evaluated syndecan-1 expression on the surface of malignant plasma cells and soluble forms of syndecan-1 in the serum of 25 newly diagnosed MM patients by flow cytometry and immunosorbent assay. Soluble syndecan-1 levels were significantly higher in MM as compared to controls (P<0.001). Cellular and soluble syndecan-1 was significantly inversely correlated (r=-0.89, P<0.001). The soluble syndecan-1 was significantly higher in non- responders to chemotherapy when compared to responders (P<0.01), and in non- survivors as compared to survivors (P<0.001). In contrast, cellular syndecan-1 expression was significantly lower in non- responders when compared to responders (P<0.01), and in non- survivors as compared to survivors (P<0.05). The levels of soluble syndecan-1 increased from stage I through stage II to stage III, whereas cellular syndecan-1 expression were decreased from high levels in stage III down to a low in stage I, with a statistically significant difference (P<0.01, P<0.05, respectively). There was a significant positive correlation between soluble syndecan-1 and plasma cell count (r=0.079, P<0.001), beta2 microglobulin (r=0.85, P<0.001), serum creatinine (r=0.84, P<0.001), C-reactive protein (r=0.082, P<0.001), alkaline phosphatase (r=0.58, P<0.05) and serum calcium (r=0.77, P<0.01) and a negative correlation with hemoglobin level (r=-0.78, P<0.01), platelets count (r=-0.82, P<0.01) and Albumin level (r=-0.64, P<0.01). Cox regression analysis using soluble syndecan-1 at mean-2SD of the controls could correctly classify patient outcome in 84.0%. The addition of beta2 microglobulin to soluble syndecan-1 increased the predictability of the patients' outcome to 96.7%. We conclude that soluble syndecan-1 levels are negatively correlated to the cellular form and that high levels of soluble syndecan-1 and lower expression of cellular syndecan-1 at diagnosis are negative prognostic factors. Assessment of soluble syndecan-1 and beta2 microglobulin at diagnosis is an independent prognostic system for MM.
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PMID:Syndecan-1 in multiple myeloma: relationship to conventional prognostic factors. 1291 39

Since the first identification of interleukin (IL)-6 as a myeloma cell growth factor by Dr. Kawano's and Dr. Klein's groups 14 years ago, numerous studies have emphasized its major roles in the emergence of malignant plasma cells in vivo and in the generation of normal plasma cells. Four transcription factors control B-cell differentiation into plasma cells. The B-cell transcription factor pax-5 is mainly responsible for a B-cell phenotype, and bcl-6 represses the plasma cell transcription factor blimp-1 and plasma cell differentiation. bcl-6 expression is triggered by CD40 and IL-4 activation. A lack of CD40 and IL-4 activation yields a down-regulation of bcl-6 expression, and IL-6 stimulation yields an up-regulation of blimp-1, mainly through STAT3 activation. Blimp-1 further down-regulates bcl-6 and pax-5 expression and makes plasma cell differentiation possible. IL-6 as well as IL-10 up-regulate XBP-1. XBP-1 is another transcription factor that is involved in plasma cell differentiation and whose gene expression is shut down by pax-5. The plasma cell transcription factors blimp-1 and XBP-1 are up-regulated, and the B-cell transcription factors bcl-6 and pax-5 are down-regulated, in malignant cells compared to B-cells. Apart from the recent identification of these 4 transcription factors, the factors involved in normal plasma cell generation are mostly unknown. Regarding malignant plasma cells, 3 categories of growth factors have been identified: (1) the IL-6 family cytokines, IL-10, and interferon alpha that activate the Janus kinase-signal transducer and activator of transcription (JAK/STAT) and mitogen-activated protein (MAP) kinase pathways; (2) growth factors activating the phosphatidylinositol (PI)-3 kinase/AKT and MAP kinase pathways, unlike the JAK/STAT pathway (insulin-like growth factor 1, hepatocyte growth factor, and members of the epidermal growth factor family able to bind syndecan-1 proteoglycan); and (3) B-cell-activating factor (BAFF) or proliferation-inducing ligand (APRIL) that activate the nuclear factor KB and PI-3 kinase/AKT pathways. BAFF and APRIL bind to BAFF receptor and TACI and are major B-cell survival factors. Recent data indicate that these various growth factors may cooperate to provide optimum signaling because they are localized together and with cytoplasmic transduction elements in caveolinlinked membrane caveolae. The identification of these myeloma cell growth factors and of the associated transduction pathways should provide novel therapeutic targets in multiple myeloma.
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PMID:Survival and proliferation factors of normal and malignant plasma cells. 1295 3

We previously found that some myeloma cell lines express the heparin-binding epidermal growth factor-like growth factor (HB-EGF) gene. As the proteoglycan syndecan-1 is an HB-EGF coreceptor as well as a hallmark of plasma cell differentiation and a marker of myeloma cells, we studied the role of HB-EGF on myeloma cell growth. The HB-EGF gene was expressed by bone marrow mononuclear cells in 8 of 8 patients with myeloma, particularly by monocytes and stromal cells, but not by purified primary myeloma cells. Six of 9 myeloma cell lines and 9 of 9 purified primary myeloma cells expressed ErbB1 or ErbB4 genes coding for HB-EGF receptor. In the presence of a low interleukin-6 (IL-6) concentration, HB-EGF stimulated the proliferation of the 6 ErbB1+ or ErbB4+ cell lines, through the phosphatidylinositol 3-kinase/AKT (PI-3K/AKT) pathway. A pan-ErbB inhibitor blocked the myeloma cell growth factor activity and the signaling induced by HB-EGF. This inhibitor induced apoptosis of patients'myeloma cells cultured with their tumor environment. It also increased patients' myeloma cell apoptosis induced by an anti-IL-6 antibody or dexamethasone. The ErbB inhibitor had no effect on the interaction between multiple myeloma cells and stromal cells. It was not toxic for nonmyeloma cells present in patients' bone marrow cultures or for the growth of hematopoietic progenitors. Altogether, these data identify ErbB receptors as putative therapeutic targets in multiple myeloma.
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PMID:An inhibitor of the EGF receptor family blocks myeloma cell growth factor activity of HB-EGF and potentiates dexamethasone or anti-IL-6 antibody-induced apoptosis. 1457 62

The identity of the cells responsible for the initiation and maintenance of multiple myeloma (MM) remains unclear largely because of the difficulty growing MM cells in vitro and in vivo. MM cell lines and clinical specimens are characterized by malignant plasma cells that express the cell surface antigen syndecan-1 (CD138); however, CD138 expression is limited to terminally differentiated plasma cells during B-cell development. Moreover, circulating B cells that are clonally related to MM plasma cells have been reported in some patients with MM. We found that human MM cell lines contained small (< 5%) subpopulations that lacked CD138 expression and had greater clonogenic potential in vitro than corresponding CD138+ plasma cells. CD138- cells from clinical MM samples were similarly clonogenic both in vitro and in nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mice, whereas CD138+ cells were not. Furthermore, CD138- cells from both cell lines and clinical samples phenotypically resembled postgerminal center B cells, and their clonogenic growth was inhibited by the anti-CD20 monoclonal antibody rituximab. These data suggest that MM "stem cells" are CD138- B cells with the ability to replicate and subsequently differentiate into malignant CD138+ plasma cells.
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PMID:Characterization of clonogenic multiple myeloma cells. 1463 Aug 3


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