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Myeloma Cells (myeloma + cell)
Kinds of Myeloma Cells Terms modified by Myeloma Cells Selected AbstractsMyeloma cells exhibit an increase in proteasome activity and an enhanced response to proteasome inhibition in the bone marrow microenvironment in vivoAMERICAN JOURNAL OF HEMATOLOGY, Issue 5 2009Claire M. Edwards The proteasome inhibitor bortezomib has a striking clinical benefit in patients with multiple myeloma. It is unknown whether the bone marrow microenvironment directly contributes to the dramatic response of myeloma cells to proteasome inhibition in vivo. We have used the well-characterized 5TGM1 murine model of myeloma to investigate myeloma growth within bone and response to the proteasome inhibitor bortezomib in vivo. Myeloma cells freshly isolated from the bone marrow of myeloma-bearing mice were found to have an increase in proteasome activity and an enhanced response to in vitro proteasome inhibition, as compared with pre-inoculation myeloma cells. Treatment of myeloma-bearing mice with bortezomib resulted in a greater reduction in tumor burden when the myeloma cells were located within the bone marrow when compared with extra-osseous sites. Our results demonstrate that myeloma cells exhibit an increase in proteasome activity and an enhanced response to bortezomib treatment when located within the bone marrow microenvironment in vivo. Am. J. Hematol., 2009. © 2009 Wiley-Liss, Inc. [source] TG101209, a novel JAK2 inhibitor, has significant in vitro activity in multiple myeloma and displays preferential cytotoxicity for CD45+ myeloma cells,AMERICAN JOURNAL OF HEMATOLOGY, Issue 9 2010Vijay Ramakrishnan Interaction of myeloma cells with the bone marrow microenvironment is mediated in large part through different cytokines, especially VEGF and IL6. These cytokines, especially IL6, leads to upregulation of the JAK/STAT pathway in myeloma cell, contributing to increased proliferation, decreased apoptosis, and acquired drug resistance. Here, we examined the preclinical activity of a novel JAK2 inhibitor TG101209. TG101209 induced dose- and time-dependent cytotoxicity in a variety of multiple myeloma (MM) cell lines. The induction of cytotoxicity was associated with inhibition of cell cycle progression and induction of apoptosis in myeloma cell lines and patient-derived plasma cells. Evaluation of U266 cell lines and patient cells, which have a mix of CD45 positive and negative cells, demonstrated more profound cytotoxicity and antiproliferative activity of the drug on the CD45+ population relative to the CD45, cells. Exploring the mechanism of action of TG101209 indicated downregulation of pJak2, pStat3, and Bcl-xl levels with upregulation of pErk and pAkt levels indicating cross talk between signaling pathways. TG101209, when used in combination with the PI3K inhibitor LY294002, demonstrated synergistic cytotoxicity against myeloma cells. Our results provide the rationale for clinical evaluation of TG101209 alone or in combination with PI3K/Akt inhibitors in MM. Am. J. Hematol., 2010. © 2010 Wiley-Liss, Inc. [source] Zoledronate has an antitumor effect and induces actin rearrangement in dexamethasone-resistant myeloma cellsEUROPEAN JOURNAL OF HAEMATOLOGY, Issue 5 2007Masayuki Koizumi Abstract New strategies are needed to overcome the resistance of multiple myeloma (MM) to dexamethasone (Dex). Several recent in vitro studies demonstrated the antitumor effect of nitrogen-containing amino-bisphosphonates (N-BPs) in various tumor cell lines. Inhibition of the prenylation of small G proteins is assumed to be one of the principal mechanisms by which N-BPs exert their effects. There have been few reports on N-BP treatment of MM cells that are resistant to Dex. Additionally, it is not known how small G proteins are altered in N-BP-treated MM cells. In this study, we evaluated the effect of the most potent N-BP, zoledronate (ZOL), on a Dex-resistant human MM cell subline (Dex-R) that we established from the well-documented RPMI8226 cell line. ZOL reduced the viability and induced apoptosis of Dex-R cells. Some of the ZOL-treated RPMI8226 cells and ZOL-treated Dex-R cells were elongated; however, elongated cells were not seen among the Dex-treated RPMI8226 cells. Furthermore, we found that portions of the small G proteins, Rho and Rap1A, were unprenylated in the ZOL-treated MM cells. Geranylgeraniol reduced the above-mentioned ZOL-induced effects. These findings suggest that ZOL may be beneficial for the treatment of Dex-resistant MM by suppressing the processing of RhoA and Rap1A. [source] Preclinical development of hybrid cell vaccines for multiple myelomaEUROPEAN JOURNAL OF HAEMATOLOGY, Issue 1 2007Renata Walewska Abstract Immunotherapy may provide alternative or supplementary treatment of multiple myeloma (MM). We propose that hybrid cells, formed by fusing professional antigen-presenting cells with malignant plasma cells, would induce immune responses capable of mediating tumour regression. The human B-lymphoblastoid cell line, HMy2, was fused in vitro with CD138+ bead-separated myeloma plasma cells from five patients with MM. The hybrid cell lines generated in these studies grew stably in tissue culture, and maintained their phenotypic and functional characteristics, providing self-renewing cell lines with potential for therapeutic vaccination. The hybrid cells stimulated allogeneic and autologous T-cell proliferative responses in vitro to a considerably greater degree than their respective parent myeloma plasma cells, and directly activated both CD4+ and CD8+ T-cell responses. The enhanced T-cell stimulation correlated with expression of CD80 on the hybrid cells, and was inhibited by CTLA4-Ig fusion protein. The hybrid cell lines expressed several tumour-associated antigens known to be expressed in myeloma. These data show that self-replicating cell lines with enhanced immunostimulatory properties and potential for therapeutic vaccination can be generated by in vitro fusion of ex vivo myeloma cells and B-lymphoblastoid cell lines. [source] Arsenic trioxide is effective in the treatment of multiple myeloma in SCID miceEUROPEAN JOURNAL OF HAEMATOLOGY, Issue 3 2004Philippe Rousselot Abstract: Objectives :,Pharmacological concentrations of arsenic trioxide (ATO) and organic arsenic melarsoprol induce apoptosis in malignant plasma cells. In an attempt to further document the interest of the arsenic in vivo, we treated severe combined immunodeficient (SCID) mice transplanted with human myeloma cells by ATO or melarsoprol. Methods :,Fifty-two SCID mice were irradiated before intraperitoneal (i.p.) injection of plasma cells from five myeloma patients. Engraftment was assessed by serial measurement of the human monoclonal immunoglobulin G (HuMIgG) concentration in mouse serum. Treatment with ATO (10 ,g/g i.p. 5 d a week), melarsoprol (30 ,g/g i.p. 5 d a week) or phosphate buffer saline was started when a sustained growth of the tumor cells was demonstrated. Results :,Seventeen mice developed the human tumor. A significant decrease in HuMIgG amounts was observed in three of five mice of the ATO group, including two that achieved an apparent complete remission persisting up to 5 months after ATO discontinuation. In these mice, no human plasma cells were detected in tissue samples collected postmortem. Soluble human interleukin-6 receptor amount, measured in mice sera as a surrogate marker of the plasma cell proliferation, varied in parallel with HuMIgG concentration. A significant difference in survival was observed between control and ATO treated mice (113 and 158 d, respectively; P = 0.01) whereas no difference could be evidenced in control and melarsoprol groups. Conclusion :,Present study confirms in vivo the in vitro effects of ATO on myeloma cells. Delayed relapses were observed suggesting that prolonged or maintenance therapy has to be considered in future clinical trials. Whether or not this will translate into clinically relevant effect of the drug in myeloma patients deserves further consideration. [source] Novel therapeutic targets in multiple myelomaEUROPEAN JOURNAL OF HAEMATOLOGY, Issue 6 2000Faith E. Davies The aim of this review is to focus on a number of key areas where recent advances in the biology of the disease have not only yielded an understanding of the disease pathogenesis but have also suggested novel treatment approaches. Factors mediating myeloma cell growth, survival and the complex interaction of myeloma cells with the bone marrowmicroenvironment have provided a framework for the rational design of therapeutic agents. The development of such biologically based treatments which target both the tumour cell and the microenvironment, in order to achieve more complete and selective eradication of myeloma cells and the maintenance of minimal residual disease states, may ultimately lead to improved disease-free survivial and potentially a cure. [source] The imbalance between Bim and Mcl-1 expression controls the survival of human myeloma cellsEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 11 2004Patricia Gomez-Bougie Abstract Multiple myeloma is a fatal B,cell malignancy characterized by the accumulation of plasma cells within the bone marrow. IL-6 is a major survival factor for myeloma cells. Bcl-2 protein family regulates pathways to apoptosis that are activated upon growth factor deprivation. Pro-apoptotic proteins that have only a single Bcl-2 homology domain, BH3-only, are potent inducers of apoptosis. In myeloma cells, Mcl-1 has been shown to be a major anti-apoptotic protein that appears to regulate cell survival through the JAK/STAT pathway. In this study, we examined the regulation of the BH3-only protein Bim and its interaction with Mcl-1. The three major Bim isoforms are expressed in myeloma cells and are negatively regulated by IL-6. Blockade of IL-6 signaling induces an up-regulation of Bim concomitant to Mcl-1 down-regulation. Of major interest, Bim is found strongly associated with Mcl-1 in viable myeloma cells while this interaction is disrupted under apoptosis induction. Of note, while Bim is also found strongly associated to Bcl-2, this interaction is not changed under apoptosis induction. Thus, in myeloma cells, Mcl-1 neutralizes Bim through complex formation and therefore prevents apoptosis. Under apoptosis induction, the disappearance of Mcl-1 allows Bim to exercise its pro-apoptotic function and to activate Bax. [source] Effects of physiological isotonic cryoprotectants on living cells during the freezing,thawing process and effects of their uptake by electroporation: Sp2 cells in alginate,trehalose solutionsHEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 6 2003Ryo Shirakashi Abstract In the present study, effects of isotonic alginate and trehalose solutions on electroporated and unpulsed control murine myeloma cells (Sp2 line) during the freezing,thawing process were evaluated. To investigate the effects of these potential cryoprotectants, microscopic examination of cell suspensions in alginate,NaCl, alginate,trehalose, or trehalose media was performed during freezing,thawing at various cooling/warming rates (e.g., ,1, ,5, and ,90 °C/min). It was found that, even at the lowest cooling rate, extracellular ice grains did not mechanically suppress cells in the trehalose-substituted medium. Moreover, at all cooling rates, intracellular ice nucleation seldom occurred in the presence of extracellular trehalose. © 2003 Wiley Periodicals, Inc. Heat Trans Asian Res, 32(6): 511,523, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.10105 [source] Multiple myeloma biology: lessons from the 5TMM modelsIMMUNOLOGICAL REVIEWS, Issue 1 2003Karin Vanderkerken Summary:, Multiple myeloma (MM) is a B cell neoplasm characterized by the monoclonal proliferation of plasma cells in the bone marrow, the development of osteolytic lesions and the induction of angiogenesis. These different processes require three-dimensional interactions, with both humoral and cellular contacts. The 5TMM models are suitable models to study these interactions. These murine models originate from spontaneously developed myeloma in elderly mice, which are propagated by in vivo transfer of the myeloma cells into young syngeneic mice. In this review we report on studies performed in the 5TMM models with special emphasis on the homing of the myeloma cells, the characterization of the migrating and proliferating clone and the identification of the isotype switch variants. The bone marrow microenvironment was further targeted with osteoprotegerin (OPG) to block the RANK/RANKL/OPG system and with potent bisphosphonates. Both treatments resulted in a significant protection against myeloma-associated bone disease, and they decreased myeloma disease, as evidenced by a lower tumor load and an increased survival of the mice. These different studies demonstrate the strength of these models, not only in unraveling basic biological processes but also in the testing of potentially new therapeutic targets. [source] Role of the Bone Marrow Microenvironment in Multiple Myeloma,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 11 2002G. David Roodman M.D., Ph.D. Abstract On June 26,27, 2001, the Sixth Research Roundtable in Multiple Myeloma, entitled "The Role of the Bone Microenvironment in Multiple Myeloma," was held and focused on the biology of cell-to-cell interactions, the mediators of bone disease, and novel treatment strategies for myeloma. Studies on cell-cell interactions showed that vascular cell adhesion molecule 1, expressed by local endothelial and stromal cells, binds to tumor cell surface integrins in which expression may be increased by tumor cell-derived chemokines such as macrophage inflammatory protein (MIP) 1,. These adhesive interactions increase production and release of vascular endothelial growth factor (VEGF). Studies on myeloma bone disease showed the ligand for receptor activator of nuclear transcription factor-,B (RANKL) was expressed on tumor cells and stromal cells associated with myeloma cells and was critical for osteoclast-induced osteolysis. Blockade of RANKL suppressed osteoclast maturation, bone resorption, and tumor development. Bisphosphonates, in addition to reducing osteoclast mobility and inducing osteoclast apoptosis, also decreased tumor cell adhesion to stroma. Immunomodulatory drugs such as thalidomide analogues targeted these tumor cell-stromal cell interactions, blocking both secretion of cytokines and activation of intracellular signaling pathways required for tumor survival and growth. These agents induced tumor cell apoptosis, decreased neovascularization, and potentiated natural killer cell activity. The proteasome inhibitor PS-341 also prevented expression of adhesion molecules and cytokines and triggered tumor cell apoptosis, even in drug-resistant cell lines, while showing minimal activity in healthy cells. In addition, potential therapeutic agents under investigation, which included RANKL antagonists, protein prenylation inhibitors, and osteoblast growth factors, were discussed. [source] Expression of CD66a in multiple myelomaJOURNAL OF CLINICAL LABORATORY ANALYSIS, Issue 2 2002Yukihiko Satoh Abstract CD66a is a member of the carcinoembryonic antigen family and has been suggested to function as an intercellular adhesion molecule and cell growth regulator. Expression of CD66a in myeloma cells was examined with mAb TS135 against CD66a transfectants of murine-transformed fibroblasts. The reactivity of mAb TS135 with CD66a, CD66c, and CD66e was revealed. CD66a in myeloma cells was considered to be detectable with this mAb, since CD66c and CD66e are not expressed in them. CD66a was detected in three myeloma cell lines and an IgM-producing B-cell line. In clinical bone marrow specimens, including 18 multiple myeloma, two primary macroglobulinemia, and a case of CLL-like chronic lymphoproliferation with monoclonal IgG production, CD66a and three conventional myeloma cell markers (PCA-1, CD38, and CD56) were examined by indirect immunofluorescence assay. The results showed that 18 out of 21 cases (86%) were CD66a+, and PCA-1 showed the highest correlation with CD66a among conventional markers. Primary macroglobulinemia and chronic lymphoproliferation were also CD66a+. Two-dimensional flow cytometry with mAbs TS135 and CD38 confirmed the reactivity of TS135 with myeloma cells in those bone marrow specimens. The findings suggest that CD66a is expressed in multiple myeloma with high frequency. J. Clin. Lab. Anal. 16:79,85, 2002. © 2002 Wiley-Liss, Inc. [source] Development and characterization of a monoclonal antibody against Taura syndrome virusJOURNAL OF FISH DISEASES, Issue 12 2009I Côté Abstract We produced a panel of monoclonal antibodies (MAbs) from the fusion of Taura syndrome virus variants from Belize (TSV-BZ) immunized BALB/cJ mouse spleen cells and non-immunoglobulin secreting SP2/0 mouse myeloma cells. One antibody, 2C4, showed strong specificity and sensitivity for TSV in dot-blot immunoassay and immunohistochemistry (IHC) analysis. The MAb reacted against native TSV-BZ, TSV variants from Sinaloa, Mexico (TSV-SI) and TSV variants from Hawaii (TSV-HI) in dot-blot immunoassay. By IHC, the antibody identified the virus in a pattern similar to the digoxigenin-labelled TSV-cDNA probe for the TSV-BZ, TSV-HI and TSV-SI variants, but not for the TSV variants from Venezuela (TSV-VE) and the TSV variants from Thailand (TSV-TH). MAb 2C4 did not react against other shrimp pathogens or with normal shrimp tissue. Western blot analysis showed a strong reaction against CP2, a region of high antigenic variability amongst TSV variants. This antibody has potential diagnostic application in detection and differentiation of certain TSV biotypes. [source] JS-K has potent anti-angiogenic activity in vitro and inhibits tumour angiogenesis in a multiple myeloma model in vivoJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 1 2010Tanyel Kiziltepe Abstract Objectives Glutathione S-transferases (GSTs) play an important role in multidrug resistance and are upregulated in multiple cancers. We have designed a prodrug class that releases nitric oxide on metabolism by GST. O2 -(2,4-Dinitrophenyl) 1-[(4-ethoxycarbonyl)piperazin-1-yl]diazen-1-ium-1,2-diolate (JS-K, a member of this class) has potent antineoplastic activity. Methods We studied the effect of JS-K on angiogenesis in human umbilical vein endothelial cells (HUVECs), OPM1 multiple myeloma cells, chick aortic rings and in mice. Key findings JS-K inhibited the proliferation of HUVECs with a 50% inhibitory concentration (IC50) of 0.432, 0.466 and 0.505 ,m at 24, 48 and 72 h, respectively. In the cord formation assay, JS-K led to a decrease in the number of cord junctions and cord length with an IC50 of 0.637 and 0.696 ,m, respectively. JS-K inhibited cell migration at 5 h using VEGF as a chemoattractant. Migration inhibition occurred with an IC50 of 0.493 ,m. In the chick aortic ring assay using VEGF or FGF-2 for vessel growth stimulation, 0.5 ,m JS-K completely inhibited vessel growth. JS-K inhibited tumour angiogenesis in vivo in NIH III mice implanted subcutaneously with OPM1 multiple myeloma cells. Conclusions JS-K is a potent inhibitor of angiogenesis in vitro and tumour vessel growth in vivo. As such, it establishes a new class of antineoplastic agent that targets the malignant cells directly as well as their microenvironment. [source] TG101209, a novel JAK2 inhibitor, has significant in vitro activity in multiple myeloma and displays preferential cytotoxicity for CD45+ myeloma cells,AMERICAN JOURNAL OF HEMATOLOGY, Issue 9 2010Vijay Ramakrishnan Interaction of myeloma cells with the bone marrow microenvironment is mediated in large part through different cytokines, especially VEGF and IL6. These cytokines, especially IL6, leads to upregulation of the JAK/STAT pathway in myeloma cell, contributing to increased proliferation, decreased apoptosis, and acquired drug resistance. Here, we examined the preclinical activity of a novel JAK2 inhibitor TG101209. TG101209 induced dose- and time-dependent cytotoxicity in a variety of multiple myeloma (MM) cell lines. The induction of cytotoxicity was associated with inhibition of cell cycle progression and induction of apoptosis in myeloma cell lines and patient-derived plasma cells. Evaluation of U266 cell lines and patient cells, which have a mix of CD45 positive and negative cells, demonstrated more profound cytotoxicity and antiproliferative activity of the drug on the CD45+ population relative to the CD45, cells. Exploring the mechanism of action of TG101209 indicated downregulation of pJak2, pStat3, and Bcl-xl levels with upregulation of pErk and pAkt levels indicating cross talk between signaling pathways. TG101209, when used in combination with the PI3K inhibitor LY294002, demonstrated synergistic cytotoxicity against myeloma cells. Our results provide the rationale for clinical evaluation of TG101209 alone or in combination with PI3K/Akt inhibitors in MM. Am. J. Hematol., 2010. © 2010 Wiley-Liss, Inc. [source] An open-label, phase 2 trial of denosumab in the treatment of relapsed or plateau-phase multiple myeloma,,AMERICAN JOURNAL OF HEMATOLOGY, Issue 10 2009Ravi Vij RANKL is a key mediator of osteoclast differentiation, activation, and survival. Preclinical data suggest that aberrant production and activation of osteoclasts may influence proliferation of multiple myeloma (MM) cells in the bone marrow. Reports have also shown that inhibiting RANKL may have a direct effect on RANK-expressing myeloma cells and a therapeutic role in treating the disease. In mouse myeloma models, inhibition of RANKL led to reduced serum paraprotein levels and tumor burden. Based on this hypothesis, this proof-of-concept, single-arm study investigated whether RANKL inhibition with denosumab could reduce serum M-protein levels in relapsed or plateau-phase myeloma subjects. All subjects received denosumab monthly, with loading doses on days 8 and 15 of month one, until disease progression or subject discontinuation. Results of this ongoing study demonstrated that no subjects in either cohort met the protocol-defined objective response criteria of complete response (CR) or partial response (PR), but that denosumab effectively inhibited the RANKL pathway regardless of previous exposure to bisphosphonates, as evidenced by suppressed levels of the bone turnover marker, serum C-terminal telopeptide of type 1 collagen (sCTx). Eleven (21%) subjects who relapsed within 3 months before study entry maintained stable disease for up to 16.5 months. Nineteen (46%) subjects with plateau-phase myeloma maintained stable disease for up to 18.3 months. The adverse event (AE) profile for denosumab and its dosing schedule in these populations was consistent with that for advanced cancer patients receiving systemic therapy. Additional controlled clinical studies of denosumab in subjects with both relapsed and plateau-phase MM are warranted. Am. J. Hematol. 2009. © 2009 Wiley-Liss, Inc. [source] Tumor-associated macrophages infiltrate plasmacytomas and can serve as cell carriers for oncolytic measles virotherapy of disseminated myeloma,AMERICAN JOURNAL OF HEMATOLOGY, Issue 7 2009Kah-Whye Peng In multiple myeloma, some of the neoplastic plasma cells are diffusely dispersed among the normal bone marrow cells (bone marrow resident), whereas others are located in discrete, well-vascularized solid tumors (plasmacytomas) that may originate in bone or soft tissue. Interactions between bone marrow-resident myeloma cells and bone marrow stromal cells (BMSCs) are important determinants of myeloma pathogenesis. However, little is known of the factors sustaining myeloma growth and cell viability at the centers of expanding plasmacytomas, where there are no BMSCs. Histologic sections of 22 plasmacytomas from myeloma patients were examined after immunostaining. Abundant CD68+, CD163+, S100-negative macrophage infiltrates were identified in all tumors, accompanied by scattered collections of CD3+ T lymphocytes. The CD68+ tumor-associated macrophages (TAM) accounted for 2,12% of nucleated cells and were evenly distributed through the parenchyma. The TAM generally had dendritic morphology, and each dendrite was in close contact with multiple plasma cells. In some cases, the TAM were strikingly clustered around CD34+ blood vessels. To determine whether cells of the monocytic lineage might be exploitable as carriers for delivery of therapeutic agents to plasmacytomas, primary human CD14+ cells were infected with oncolytic measles virus and administered intravenously to mice bearing KAS6/1 human myeloma xenografts. The cell carriers localized to KAS6/1 tumors, where they transferred MV infection to myeloma cells and prolonged the survival of mice bearing disseminated human myeloma disease. Thus, TAM are a universal stromal component of the plasmacytomas of myeloma patients and may offer a promising new target for therapeutic exploitation. Am. J. Hematol. 2009. © 2009 Wiley-Liss, Inc. [source] Myeloma cells exhibit an increase in proteasome activity and an enhanced response to proteasome inhibition in the bone marrow microenvironment in vivoAMERICAN JOURNAL OF HEMATOLOGY, Issue 5 2009Claire M. Edwards The proteasome inhibitor bortezomib has a striking clinical benefit in patients with multiple myeloma. It is unknown whether the bone marrow microenvironment directly contributes to the dramatic response of myeloma cells to proteasome inhibition in vivo. We have used the well-characterized 5TGM1 murine model of myeloma to investigate myeloma growth within bone and response to the proteasome inhibitor bortezomib in vivo. Myeloma cells freshly isolated from the bone marrow of myeloma-bearing mice were found to have an increase in proteasome activity and an enhanced response to in vitro proteasome inhibition, as compared with pre-inoculation myeloma cells. Treatment of myeloma-bearing mice with bortezomib resulted in a greater reduction in tumor burden when the myeloma cells were located within the bone marrow when compared with extra-osseous sites. Our results demonstrate that myeloma cells exhibit an increase in proteasome activity and an enhanced response to bortezomib treatment when located within the bone marrow microenvironment in vivo. Am. J. Hematol., 2009. © 2009 Wiley-Liss, Inc. [source] Production and partial characterization of mouse monoclonal antibodies recognizing common cytokine receptor gamma chain (,c) of human, mouse and primate origin,APMIS, Issue 10 2001KAROLINA LUNDIN Monoclonal antibodies specific for the common cytokine receptor gamma chain, ,c, were produced using traditional hybridoma technology. Fusion of P3X63-Ag8.653 myeloma cells with splenocytes from Balb/c mice immunized with Spodoptera frugiperda insect cells infected with the recombinant baculovirus VL1392-hIL-2R, resulted in several hybridoma cell clones producing monoclonal ,c -specific antibodies. Four of these antibody-producing clones, IIIC3, IIIE8, IG3 and IF10C5, were further characterized by immunoblotting, flow cytometry and ELISA. Data are presented demonstrating that the generated monoclonal antibodies can identify the extracellular domain of the common cytokine receptor , chain of human and mouse origin, and two of the antibodies recognize ,c of primate origin as well. [source] Detailed understanding of enhanced specific antibody productivity in NS0 myeloma cellsBIOTECHNOLOGY & BIOENGINEERING, Issue 1 2009Soo Hean Gary Khoo Abstract The understanding of how cellular productivity is modulated in cell lines is of significant importance in the biopharmaceutical industry. Often, single molecular mechanisms fail to fully explain how specific antibody productivity is enhanced during proliferation arrest. Previously, we reported that certain physiological changes occur when proliferation is arrested by p21CIP1 over expression. In this work, we correlate physiological and molecular factors to enhance antibody productivity. Using biomass, cell volume and total cellular protein content as a basis for determining specific productivity, it was found that total cellular protein correlated best with cellular productivity. This meant that there was no preferential increase in antibody production relative to cellular proteins in arrested cultures. However, molecular analysis of mRNA transcription and stability indicated that both processes were altered in arrested cultures resulting in up to threefold increased heavy chain mRNA levels. While flow cytometric analysis revealed that arrested cells had elevated translational capacity for both heavy and light chains, the heavy to light chain polypeptide ratio was 10,50% higher than in the control. This resulted in a lower extracellular accumulation of light chains and a better utilization of cellular resources for the formation of complete antibodies. Active transcriptional regulation of heavy and light chain mRNA and the modulation of translational activities play a vital role in the modulation of overall antibody productivity of these cells. The combined effect of heavy chain mRNA enhancement and the increased cellular assembly capacity was determined to effectively increase specific productivity. Biotechnol. Bioeng. 2009;102: 188,199. © 2008 Wiley Periodicals, Inc. [source] Dynamic analysis of GS-NS0 cells producing a recombinant monoclonal antibody during fed-batch cultureBIOTECHNOLOGY & BIOENGINEERING, Issue 2 2007Scott H. Stansfield Abstract In this study we have analyzed the dynamic covariation of the mammalian cell proteome with respect to functional phenotype during fed-batch culture of NS0 murine myeloma cells producing a recombinant IgG4 monoclonal antibody. GS-NS0 cells were cultured in duplicate 10 L bioreactors (36.5°C, 15% DOT, pH 7.0) for 335 h and supplemented with a continuous feed stream after 120 h. Cell-specific growth rate declined continuously after 72 h of culture. Cell-specific recombinant monoclonal antibody production rate (qP) varied sixfold through culture. Whilst qP correlated with relative recombinant heavy chain mRNA abundance up to 216 h, qP subsequently declined, independent of recombinant heavy chain or light chain mRNA abundance. GS-NS0 cultures were sampled at 48 h intervals between 24 and 264 h of culture for proteomic analyses. Total protein abundance and nascent polypeptide synthesis was determined by 2D PAGE of unlabeled proteins visualized by SYPRO® Ruby and autoradiography of 35S-labeled polypeptides, respectively. Covariation of nascent polypeptide synthesis and abundance with biomass-specific cell growth, glucose and glutamate consumption, lactate and Mab production rates were then examined using two partial least squares regression models. Most changes in polypeptide synthesis or abundance for proteins previously identified by mass spectrometry were positively correlated with biomass-specific growth rate. We conclude that the substantial transitions in cell physiology and qP that occur during culture utilize a relatively constant complement of the most abundant host cell machines that vary primarily with respect to induced changes in cell growth rate. Biotechnol. Bioeng. 2007;97: 410,424. © 2006 Wiley Periodicals, Inc. [source] Analysis of the role of GADD153 in the control of apoptosis in NS0 myeloma cellsBIOTECHNOLOGY & BIOENGINEERING, Issue 7 2002Idsada Lengwehasatit Abstract Apoptosis can limit the maximum production of recombinant protein expression from cultured mammalian cells. This article focuses on the links between nutrient deprivation, ER perturbation, the regulation of (growth arrest and DNA damage inducible gene 153) GADD153 expression and apoptosis. During batch culture, decreases in glucose and glutamine correlated with an increase in apoptotic cells. This event was paralleled by a simultaneous increase in GADD153 expression. The expression of GADD153 in batch culture was suppressed by the addition of nutrients and with fed-batch culture the onset of apoptosis was delayed but not completely prevented. In defined stress conditions, glucose deprivation had the greatest effect on cell death when compared to glutamine deprivation or the addition of tunicamycin (an inhibitor of glycosylation), added to generate endoplasmic reticulum stress. However, the contribution of apoptosis to overall cell death (as judged by morphology) was smaller in conditions of glucose deprivation than in glutamine deprivation or tunicamycin treatment. Transient activation of GADD153 expression was found to occur in response to all stresses and occurred prior to detection of the onset of cell death. These results imply that GADD153 expression is either a trigger for apoptosis or offers a valid indicator of the likelihood of cell death arising from stresses of relevance to the bioreactor environment. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 80: 719,730, 2002. [source] Defined Protein-Free NS0 Myeloma Cell Cultures: Stimulation of Proliferation by Conditioned Medium FactorsBIOTECHNOLOGY PROGRESS, Issue 1 2005Erika Spens A chemically defined, protein-free, and animal-component-free medium, designated RITM01, has been developed for NS0 myeloma cells. The basal medium used was a commercial serum-free and protein-free hybridoma medium, which was supplemented with phosphatidylcholine, cholesterol, ,-cyclodextrin, and ferric citrate. Increasing the amino acid concentration significantly improved cell growth. An NS0 cell line, constitutively producing a human IgG1 antibody, reached a peak cell density of 3 × 106 cells mL,1 in this medium. The antibody yield was 195 mg L,1 in batch culture, which is a 3-fold increase compared to that of a standard serum-supplemented medium, even though the cell yield was the same. The increase in antibody yield was a consequence of a longer growth phase and a slight increase in specific antibody production rate at low specific proliferation rates. Adaptation of the NS0 myeloma cell line to the protein-free conditions required about 3 weeks before viability and cell densities were stabilized. Most probably, changes in gene expression and phenotypic behavior necessary for cell survival and proliferation occurred. We hypothesize that mitogenic factors produced by the cells themselves are involved in autocrine control of proliferation. To investigate the presence of such factors, the effect of conditioned (spent) medium (CM) on cell growth and proliferation was studied. Ten-fold concentrated CM, harvested at a cell density of 2 × 106 cells mL,1, had a clear positive effect on proliferation even if supplied at only 2.5% (v/v). CM was found to contain significant amounts of extracellular proteins other than the antibody. Fractionation of CM on a gel filtration column and subsequent supplementation of new NS0 cultures with the individual fractions showed that factors eluting at 20,25 kDa decreased the lag phase and increased the peak cell density as compared to control cultures. Identification of autocrine factors involved in regulation of proliferation may lead to completely new strategies for control of growth and product formation in animal cell processes. [source] Inhibitor of DASH proteases affects expression of adhesion molecules in osteoclasts and reduces myeloma growth and bone diseaseBRITISH JOURNAL OF HAEMATOLOGY, Issue 6 2009Angela Pennisi Summary Dipeptidyl peptidase (DPP) IV activity and/or structure homologues (DASH) are serine proteases implicated in tumourigenesis. We previously found that a DASH protease, fibroblast activation protein (FAP), was involved in osteoclast-induced myeloma growth. Here we further demonstrated expression of various adhesion molecules in osteoclasts cultured alone or cocultured with myeloma cells, and tested the effects of DASH inhibitor, PT-100, on myeloma cell growth, bone disease, osteoclast differentiation and activity, and expression of adhesion molecules in osteoclasts. PT-100 had no direct effects on viability of myeloma cells or mature osteoclasts, but significantly reduced survival of myeloma cells cocultured with osteoclasts. Real-time PCR array for 85 adhesion molecules revealed upregulation of 17 genes in osteoclasts after coculture with myeloma cells. Treatment of myeloma/osteoclast cocultures with PT-100 significantly downregulated 18 of 85 tested genes in osteoclasts, some of which are known to play roles in tumourigenesis and osteoclastogenesis. PT-100 also inhibited osteoclast differentiation and subsequent pit formation. Resorption activity of mature osteoclasts and differentiation of osteoblasts were not affected by PT-100. In primary myelomatous severe combined immunodeficient (SCID)-hu mice PT-100 reduced osteoclast activity, bone resorption and tumour burden. These data demonstrated that DASH proteases are involved in myeloma bone disease and tumour growth. [source] Gene expression of anti- and pro-apoptotic proteins in malignant and normal plasma cellsBRITISH JOURNAL OF HAEMATOLOGY, Issue 1 2009Michel Jourdan Summary The survival of malignant plasma cells is a key event in disease occurrence, progression and chemoresistance. Using DNA-microarrays, we analysed the expression of genes coding for 58 proteins linked with extrinsic and intrinsic apoptotic pathways, caspases and inhibitor of apoptosis proteins. We considered six memory B cells (MBC), seven plasmablasts (PPC), seven bone marrow plasma cells (BMPC) and purified myeloma cells (MMC) from 92 newly-diagnosed patients. Forty out of the 58 probe sets enabled the separation of MBC, PPC and BMPC in three homogeneous clusters, characterized by an elevated expression of TNFRSF10A, TNFRSF10B, BCL2A1, CASP8, CASP9 and PMAIP1 genes for MBC, of FAS, FADD, AIFM1, BIRC5, CASP CASP2, CASP3 and CASP6 for PPC and of BCL2, MCL1, BID, BIRC3 and XIAP for BMPC. Thus, B cell differentiation was associated with change of expression of pro-apoptotic and anti-apoptotic genes. Regarding MMC, the major finding was TRAIL upregulation that might be counteracted by a high osteoprotegerin production by BM stromal cells and a decreased expression of FAS, APAF1 and BNIP3 compared to normal BMPC. Out of the 40 genes, CASP2 and BIRC5 expression in MMC had adverse prognosis in two independent series of previously-untreated patients. [source] Galectin-1 supports the survival of CD45RA(,) primary myeloma cells in vitroBRITISH JOURNAL OF HAEMATOLOGY, Issue 5 2008Saeid Abroun Summary The survival and proliferation of human myeloma cells are considered to be heavily dependent on the microenvironment of bone marrow (BM). This study confirmed that galectin-1 (Gal-1) and SDF-1, were produced by bone marrow mononuclear cells of myeloma patients. The addition of Gal-1 and SDF-1, to a serum-free synthetic medium, maintained the viability of primary myeloma cells for 2 weeks similar to that before culture. While Gal-1 reduced the viable cell number in CD45RA(+) B cell lines, it maintained the viability of CD45(,) U266 and CD45RA(,)RO(+) ILKM3 myeloma cell lines in the synthetic medium. This was confirmed with the transfection of the PTPRC (CD45) RA, -RB, or -RO gene into CD45(,) U266 cells. The combination of Gal-1 and SDF-1, significantly induced phosphorylation of Akt and IkB, while the phosphorylation of ERK1/2 was significantly reduced in CD45RA(+) U266 and Raji cells but not CD45(,) or CD45RA(,) U266 cells. Furthermore, we confirmed that Gal-1 bound to CD45RA in CD45RA(+) Raji cells, and also physically interacted with ,1-integrin by immunoprecipitation followed by Western blotting and confocal microscopy. The results suggest that Gal-1 has two different actions depending on its binding partner, and supports the survival of CD45RA(,) myeloma cells. [source] Pure erythroid leukaemia with leukaemic cells mimicking myeloma cellsBRITISH JOURNAL OF HAEMATOLOGY, Issue 1 2008Rosario Mª Morales Camacho No abstract is available for this article. [source] Inhibition of Akt induces significant downregulation of survivin and cytotoxicity in human multiple myeloma cellsBRITISH JOURNAL OF HAEMATOLOGY, Issue 6 2007Teru Hideshima Summary Akt mediates growth and drug resistance in multiple myeloma (MM) cells in the bone marrow (BM) microenvironment. We have shown that a novel Akt inhibitor Perifosine induces significant cytotoxicity in MM cells in the BM milieu. This study further delineated molecular mechanisms whereby Perifosine triggered cytotoxicity in MM cells. Neither the intensity of Jun NH2 -terminal kinase phosphorylation nor caspase/poly (ADP-ribose) polymerase cleavage correlated with Perifosine-induced cytotoxicity in MM.1S, INA6, OPM1 and OPM2 MM cells. However, survivin, which regulates caspase-3 activity, was markedly downregulated by Perifosine treatment, without changes in other anti-apoptotic proteins. Downregulation of survivin by siRNA significantly inhibited OPM1 MM cell growth, confirming that survivin mediates MM cell survival. Perifosine significantly downregulated both function and protein expression of ,-catenin. Co-culture with BM stromal cells (BMSCs) upregulated both ,-catenin and survivin expression in MM cells, which was blocked by Perifosine. Importantly, Perifosine treatment also downregulated survivin expression in human MM cells grown in vivo in a severe combined immunodeficient mouse xenograft model. Finally, Perifosine inhibited bortezomib-induced upregulation of survivin, associated with enhanced cytotoxicity of combined bortezomib and Perifosine treatment. These preclinical studies provide the framework for clinical trials of bortezomib with Perifosine to improve patient outcome in MM. [source] Didox, a ribonucleotide reductase inhibitor, induces apoptosis and inhibits DNA repair in multiple myeloma cellsBRITISH JOURNAL OF HAEMATOLOGY, Issue 1 2006N. Raje Summary Ribonucleotide reductase (RR) is the enzyme that catalyses the rate-limiting step in DNA synthesis, the production of deoxynucleotides. RR activity is markedly elevated in tumour tissue and is crucial for cell division. It is therefore an excellent target for cancer chemotherapy. This study examined the anti-myeloma activity of Didox (3,4-Dihydroxybenzohydroxamic acid), a novel RR inhibitor (RRI). Our data showed that Didox induced caspase-dependent multiple myeloma (MM) cell apoptosis. Didox, unlike other RRIs that mainly target the pyrimidine metabolism pathway, targets both purine and pyrimidine metabolism pathways in MM, as demonstrated by transcriptional profiling using the Affymetrix U133A 2·0 gene chip. Specifically, a ,2-fold downregulation of genes in these anabolic pathways was shown as early as 12 h after exposure to Didox. Furthermore, apoptosis was accompanied by downregulation of bcl family proteins including bcl-2, bclxl, and XIAP. Importantly, RR M1 component transcript was also downregulated, associated with decreased protein expression. Genes involved in DNA repair mechanisms, specifically RAD 51 homologue, were also downregulated. As Didox acts on MM cells by inhibiting DNA synthesis and repair, combination studies with melphalan, an agent commonly used in MM, were performed. A strong in vitro synergism was shown, with combination indices of <0·7 as determined by the Chou,Talalay method. These studies therefore provide the preclinical rationale for evaluation of Didox, alone and in combination with DNA-damaging agents, to improve patient outcome in MM. [source] The synthetic furanonaphthoquinone induces growth arrest, apoptosis and differentiation in a variety of leukaemias and multiple myeloma cellsBRITISH JOURNAL OF HAEMATOLOGY, Issue 4 2005Julian C. Desmond Summary 2-Methyl-naphtho[2,3- b]furan-4,9-dione (FNQ3), a synthetic analogue of the quinone kigelinone, has demonstrated a real potential for use in the treatment of a variety of solid tumours. Unlike other quinones, such as mitomycin-C and adriamycin, the cytotoxicity of FNQ3 is often 10- to 14-fold more potent towards the tumour cells than their normal counterparts. We report, for the first time, that the drug had activity against a broad spectrum of leukaemias and multiple myeloma cells. It decreased the growth of acute myeloid leukaemia (AML) and multiple myeloma cell lines in a dose-dependent fashion (50% inhibitory concentration ,1·25 ,g/ml against most of the leukaemia cell lines). This dose apparently initiated mitochondrial collapse as measured by depolarisation of the mitochondrial membrane. FNQ3 potentiated the differentiation of HL-60 myeloid cells in the presence of either 1,, 25(OH)2 dihydroxyvitamin D3 [1,,25(OH)2D3] or all- trans -retinoic acid (ATRA). FNQ3 inhibited the proliferation of primary AML cells while inducing apoptosis. Eleven of 14 (79%) AML marrow samples had a prominent decrease in their clonogenic growth when cultured in the presence of the drug. In summary, this drug has growth inhibitory, apoptotic and differentiative effects against myeloid leukaemias and multiple myeloma cells. FNQ3 may represent a new therapeutic approach to these malignancies. [source] Fusion of dendritic cells with multiple myeloma cells results in maturation and enhanced antigen presentationBRITISH JOURNAL OF HAEMATOLOGY, Issue 5 2005Baldev Vasir Summary Dendritic cells (DCs) are potent antigen-presenting cells that are uniquely capable of inducing primary immune responses. Although tumour cells may directly inhibit DC maturation, exposure to tumour products may also result in their activation. Fusions of cancer cells and DCs are being explored as cancer vaccines. The effect of tumour cell fusion on DC maturation and their functional characteristics has not been defined. In the present study, immature and mature DC generated from human CD34+ and peripheral blood precursors were fused to multiple myeloma cells in the presence of polyethylene glycol. Fusion of both immature and mature DCs with tumour cells resulted in an activated phenotype. In this regard, fusion cells expressed interleukin-12, a cytokine essential for the induction of T-helper cell type 1 immunity. In contrast to immature DCs, fusion cells also strongly expressed CC-chemokine receptor R7, which is responsible for DC migration to draining lymph nodes. Fusions generated with both immature and mature DCs also potently stimulated T-cell expression of , -interferon and cytotoxic T lymphocyte killing of tumour targets. These findings demonstrate that tumour cell fusion induces DC maturation and the development of an activated phenotype necessary for their effectiveness as cancer vaccines. [source] | |||||||||||||||||||||||||||||||