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)

Thalidomide (Thal) achieves responses even in the setting of refractory multiple myeloma (MM). Although increased angiogenesis in MM bone marrow and the antiangiogenic effect of Thal formed the empiric basis for its use in MM, we have shown that Thal and its immunomodulatory analogs (IMiDs) directly induce apoptosis or growth arrest of MM cells, alter adhesion of MM cells to bone marrow stromal cells, inhibit the production of cytokines (interleukin-6 and vascular endothelial growth factor) in bone marrow, and stimulate natural killer cell anti-MM immunity. In the present study, we demonstrate that the IMiDs trigger activation of caspase-8, enhance MM cell sensitivity to Fas-induced apoptosis, and down-regulate nuclear factor (NF)-kappa B activity as well as expression of cellular inhibitor of apoptosis protein-2 and FLICE inhibitory protein. IMiDs also block the stimulatory effect of insulinlike growth factor-1 on NF-kappa B activity and potentiate the activity of TNF-related apoptosis-inducing ligand (TRAIL/Apo2L), dexamethasone, and proteasome inhibitor (PS-341) therapy. These studies both delineate the mechanism of action of IMiDs against MM cells in vitro and form the basis for clinical trials of these agents, alone and coupled with conventional and other novel therapies, to improve outcome in MM.
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PMID:Apoptotic signaling induced by immunomodulatory thalidomide analogs in human multiple myeloma cells: therapeutic implications. 1203 84

Interleukin 6 (IL-6) is an important survival and growth factor for myeloma cells and exerts its effects by activating several transduction pathways, including the Ras cascade. As farnesylation of the activated Ras oncogene product by protein farnesyltransferase (FTase) is a critical step for Ras functional activity, FTase has emerged as a potential target for the development of new anti-cancer agents. Based on our previous demonstration that IL-6-producing myeloma cells are refractory to drug-induced apoptosis, we have analysed the effect of manumycin, a natural FTase inhibitor, on IL-6-producing myeloma cells resistant to Fas-, dexamethasone- and doxorubicin-induced apoptosis. Treatment of myeloma cells with manumycin prevented cell proliferation and induced apoptosis. Western blotting experiments demonstrated that this effect was related to inhibition of the post-translational Ras processing.Further analysis showed that manumycin-induced apoptosis involved caspase-3. Activation of caspase-3, in fact, was observed in 6 h-treated myeloma cells expressing Apo 2.7 antigen, the marker of early apoptosis, whereas their treatment with cell-permeable DEVD-fmk, that irreversibly inhibits caspase-3 activity, prevented their apoptosis. Over-expression of caspase-3 was also demonstrated by reverse transcription-polymerase chain reaction. Finally, over-expression of Bcl-2 and its homologue Bcl-xL was observed in manumycin-treated cells as well as in control myeloma cells, implying that the Bcl-2 family is not involved. FTase inhibitors may thus be proposed as a potential pharmacological weapon, as they block the Ras pathway and induce the apoptosis of drug-resistant IL-6-producing myeloma cells.
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PMID:Manumycin inhibits farnesyltransferase and induces apoptosis of drug-resistant interleukin 6-producing myeloma cells. 1210 Jan 43

The proteasome inhibitor PS-341 inhibits IkappaB degradation, prevents NF-kappaB activation, and induces apoptosis in several types of cancer cells, including chemoresistant multiple myeloma (MM) cells. PS-341 has marked clinical activity even in the setting of relapsed refractory MM. However, PS-341-induced apoptotic cascade(s) are not yet fully defined. By using gene expression profiling, we characterized the molecular sequelae of PS-341 treatment in MM cells and further focused on molecular pathways responsible for the anticancer actions of this promising agent. The transcriptional profile of PS-341-treated cells involved down-regulation of growth/survival signaling pathways, and up-regulation of molecules implicated in proapoptotic cascades (which are both consistent with the proapoptotic effect of proteasome inhibition), as well as up-regulation of heat-shock proteins and ubiquitin/proteasome pathway members (which can correspond to stress responses against proteasome inhibition). Further studies on these pathways showed that PS-341 decreases the levels of several antiapoptotic proteins and triggers a dual apoptotic pathway of mitochondrial cytochrome c release and caspase-9 activation, as well as activation of Jun kinase and a Fas/caspase-8-dependent apoptotic pathway [which is inhibited by a dominant negative (decoy) Fas construct]. Stimulation with IGF-1, as well as overexpression of Bcl-2 or constitutively active Akt in MM cells also modestly attenuates PS-341-induced cell death, whereas inhibitors of the BH3 domain of Bcl-2 family members or the heat-shock protein 90 enhance tumor cell sensitivity to proteasome inhibition. These data provide both insight into the molecular mechanisms of antitumor activity of PS-341 and the rationale for future clinical trials of PS-341, in combination with conventional and novel therapies, to improve patient outcome in MM.
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PMID:Molecular sequelae of proteasome inhibition in human multiple myeloma cells. 1239 22

Anemia of variable severity occurs in more than two-thirds of patients with multiple myeloma (MM). Besides the altered cytokine network, chronic erythropoietin deficiency, blood loss and hemolysis, we have shown that deregulated myeloma cell apoptosis may contribute to progressive destruction of the erythroid matrix by inducing erythroblast cytotoxicity. To exert this effect, highly malignant plasma cells overexpress both Fas-ligand (Fas-L) and TRAIL, which efficiently trigger the death of immature erythroblasts. In view of severe progression of MM in patients with Fas-L/TRAIL-based anemia, overexpression of these apoptogen receptors may characterize a peculiar cytotoxic-apoptogenic phenotype in malignant plasma cells. Early immunophenotyping of myeloma cells could thus help to identify patients with a higher risk of erythropoiesis exhaustion.
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PMID:Anemia in multiple myeloma: role of deregulated plasma cell apoptosis. 1240 May 94

Anemia of variable severity occurs in more than two-thirds of patients with multiple myeloma (MM). Besides the altered cytokine network, chronic erythropoietn deficiency, blood loss and hemolysis, we have shown that deregulated myeloma cell apoptosis contributes to progressive destruction of the erythroid matrix by inducing erythroblast cytotoxicity. To exert this effect, highly malignant plasma cells overexpress both Fas-L and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), which efficiently trigger the death of immature erythroblasts. However, this Fas-L/TRAIL-based anemia occurs in particular in patients with severely progressive MM, thus suggesting that these apoptogen receptors may characterize a peculiar cytotoxic-apoptogenic phenotype of malignancy. Immunophenotyping of myeloma cells could help to identify patients with a higher risk of erythropoiesis exhaustion.
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PMID:Upregulation of erythroblast apoptosis by malignant plasma cells: a new pathogenetic mechanism of anemia in multiple myeloma. 1273 14

Typical features of multiple myeloma (MM) are osteolytic lesions and severely affected bone regeneration. This study of 53 MM patients demonstrates an enhancement of osteoblast cytotoxicity by malignant myeloma cells via the upregulation of apoptogenic receptors, including Fas ligand (Fas-L) and tumour-necrosis-factor-related apoptosis inducing ligand (TRAIL). Both were significantly increased in the marrow myeloma cells of patients with extensive osteolytic lesions in a fashion similar to the highly malignant human myeloma cell line MCC-2. Osteoblasts from these subjects over-expressed Fas and death receptor (DR) 4/5 and underwent dramatic apoptosis when co-cultured with either MCC-2 or autologous myeloma cells. In osteoblast and myeloma cell co-cultures, monocyte chemoattractant protein 1 (MCP-1) mRNA was upregulated in osteoblasts from patients with severe bone disease in parallel with increased CC-chemokine receptor R2 (CCR2) expression, the ligand of MCP-1, in the myeloma cells. This chemokine was shown to activate malignant cell migration in vitro. An upregulation of ICAM-1 expression occurred in osteoblasts from patients with active skeleton disease. This upregulation appeared to be an effect of malignant plasma cell contact, as MCC-2 co-culture greatly enhanced ICAM-1 production by resting osteoblasts from patients without skeleton involvement. Our results suggest that osteoblasts in active myeloma are functionally exhausted and promptly undergo apoptosis in the presence of myeloma cells from patients with severe bone disease. It is suggested that this cytotoxic effect plays a pivotal role in the pathogenesis of defective bone repair.
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PMID:Upregulation of osteoblast apoptosis by malignant plasma cells: a role in myeloma bone disease. 1282 44

CD28, which is expressed on most T cells, can provide a costimulatory signal during T cell activation. Although principally considered to be a T cell-associated molecule, CD28 has been seen to be expressed on mast cells and natural killer cells, as well as on plasma and myeloma cells, but not on cells representing earlier stages of B cell development. Here were report that CD28 was expressed on Epstein-Barr virus (EBV)-positive B lymphoblastoid and AIDS-associated non-Hodgkin's lymphoma cell lines. These cells also expressed the ligands for CD28, B7-1 and B7-2, but not CTLA-4. Furthermore, peripheral blood B cells infected with EBV ex vivo expressed CD28 after infection. Cross-linking with a stimulatory anti-CD28 antibody resulted in an increased expression of CD71 (transferrin receptor) or CD25 (interleukin-2 alpha receptor subunit). The addition of a blocking CTLA-4-Ig fusion protein, or antisense oligonucleotides for CD28, resulted in a decreased expression of these molecules. In 1 cell line, the addition of an anti-CD28 stimulatory antibody reduced Fas-induced apoptosis, and antisense oligonucleotide-induced inhibition of CD28 expression enhanced Fas-mediated apoptosis. Overall, these results suggest a role for CD28 and its ligands, B7-1 and B7-2, in homotypic interactions in EBV+ B cell lines, which may mediate cellular activation and/or viability.
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PMID:Expression and function of CD28 on Epstein-Barr virus-positive B cell lines and AIDS-associated non-Hodgkin's lymphoma cell lines. 1285 3

Anemia is a prominent feature of multiple myeloma (MM) and is commonly associated with clinical progression of MM. In addition to being affected by a number of pathogenetic events, including imbalance of the cytokine network, inappropriate erythropoietin (EPO) levels, blood loss, and hemolysis, the erythroid matrix is chronically deteriorated by the malignant plasma cell clone that activates a cytotoxic mechanism directed at the erythroid progenitors. In particular, malignant plasma cells express very high levels of apoptogenic receptors, including both Fas ligand and tumor necrosis factor-related apoptosis-inducing ligand, which trigger apoptosis of immature erythroblasts by stimulating specific death receptors, namely Fas and the complex DR4/DR5. Erythroid cells also weakly express the transcription factor GATA-1, which drives erythroblast maturation by inhibiting apoptosis through antiapoptotic molecules such as EPO and Bcl-xL. This newly discovered pathogenetic mechanism of anemia in MM is based on persistent erythroblast cytotoxicity within the bone marrow that leads to progressive destruction of the erythroid matrix.
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PMID:Recent advances in understanding the pathogenesis of anemia in multiple myeloma. 1295 5

Previous studies have demonstrated that cotreatment with mitogen activated-protein kinase kinase (MEK) 1/2 inhibitors (e.g., PD184352) and the checkpoint abrogator 7-hydroxystaurosporine (UCN-01) dramatically induces apoptosis in a variety of human leukemia and multiple myeloma cell types. The purpose of this study was to evaluate the roles of Bcl-2 family members and the relative contribution of the intrinsic mitochondrial versus the extrinsic receptor-related apoptotic pathways to MEK inhibitors/UCN-01-induced leukemic cell death. Cotreatment of U937 cells with PD184352 and UCN-01 resulted in the activation of procaspase-3, -9, and -8 as well as Bid cleavage. PD184352/UCN-01-induced mitochondrial dysfunction and apoptosis were both substantially attenuated in cells ectopically expressing Bcl-2, an N-terminal phosphorylation loop-deleted mutant Bcl-2, or Bcl-xL, but not in cells expressing dominant-negative (DN) caspase-8, cytokine response modifier A (cowpox virus-encoded antiapoptotic protein), or DN Fas-associated death domain. Coadministration of tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) or TNF-alpha substantially increased MEK inhibitors (e.g., PD184352 or U0126)/UCN-01-induced mitochondrial dysfunction, activation of procaspase-8 and Bid, and apoptosis in Bcl-2- and Bcl-xL-overexpressing cells but not in those in which the extrinsic pathway was interrupted. Together, these findings suggest that the MEK inhibitors/UCN-01 regimen primarily induces leukemic cell apoptosis by engaging the intrinsic, mitochondrial apoptotic pathway and that resistance to these events conferred by increased expression of certain antiapoptotic Bcl-2 family members can be overcome, at least in part, by coadministration of TRAIL and other agents that activate the extrinsic apoptotic cascade.
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PMID:Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) promotes mitochondrial dysfunction and apoptosis induced by 7-hydroxystaurosporine and mitogen-activated protein kinase kinase inhibitors in human leukemia cells that ectopically express Bcl-2 and Bcl-xL. 1464 70

The synthetic oleanane triterpenoid 2-cyano-3,12-dioxoolean-1,9-dien-28-oic acid (CDDO) and its chemical derivatives induce differentiation and apoptosis of human leukemia cells. The precise mechanisms responsible for the effects of CDDO, however, remain unclear. In the present study, we examined the effects of CDDO and its C-28 imidazolide ester (CDDO-Im) on apoptosis of multiple myeloma (MM) cells. The results show that both CDDO and CDDO-Im are potent inducers of MM cell apoptosis and that CDDO-Im is more active than CDDO. CDDO-Im treatment was associated with (a) depletion of glutathione, (b) increases in reactive oxygen species, (c) a reduction of the Fas-associated death domain (FADD)-like interleukin-1-converting enzyme (FLICE) inhibitory protein, (d) activation of caspase-8, and (e) a decrease of the mitochondrial transmembrane potential. The reducing agents, N-acetyl-L-cysteine, DTT, and catalase inhibited each of these CDDO-Im-induced proapoptotic signals. Inhibition of caspase-8 with z-IETD-fmk also abrogated CDDO-Im-induced decreases of the mitochondrial transmembrane potential and inhibited apoptosis. These results demonstrate that CDDO-Im disrupts intracellular redox balance and thereby activates the extrinsic caspase-8-dependent apoptotic pathway. We further show that CDDO-Im induces apoptosis of primary MM cells at submicromolar concentrations and that MM cells are more sensitive to this agent than normal bone marrow mononuclear cells. These results suggest that CDDO compounds have potential as new agents for the treatment of MM.
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PMID:Induction of redox imbalance and apoptosis in multiple myeloma cells by the novel triterpenoid 2-cyano-3,12-dioxoolean-1,9-dien-28-oic acid. 1474 74


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