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

Osteoclastogenesis is commonly associated with various age-related diseases, including cancer. A member of the tumor necrosis factor superfamily, receptor activator of nuclear factor-kappaB (NF-kappaB) ligand (RANKL), has been shown to play a critical role in osteoclast formation and bone resorption. Thus, agents that suppress RANKL signaling have a potential to suppress bone loss. In this report, we investigated the effect of 1'-acetoxychavicol acetate (ACA), a component of Alpina galanga, on RANKL signaling and consequent osteoclastogenesis in RAW 264.7 cells, a murine monocytic cell line. Treatment of these cells with RANKL activated NF-kappaB, and coexposure of the cells to ACA completely suppressed RANKL-induced NF-kappaB activation in a time- and concentration-dependent manner. The suppression of NF-kappaB by ACA was mediated through suppression of RANKL-induced activation of IkappaBalpha kinase, IkappaBalpha phosphorylation, and IkappaBalpha degradation. Furthermore, incubation of monocytic cells with RANKL induced osteoclastogenesis, and ACA suppressed it. Inhibition of osteoclastogenesis was maximal when cells were simultaneously exposed to ACA and RANKL and minimum when ACA was added 2 days after RANKL. ACA also inhibited the osteoclastogenesis induced by human breast cancer MCF-7 cells, multiple myeloma MM1 cells, and head and neck squamous cell carcinoma LICR-LON-HN5 cells. These results indicate that ACA is an effective blocker of RANKL-induced NF-kappaB activation and of osteoclastogenesis induced by RANKL and tumor cells, suggesting its potential as a therapeutic agent for osteoporosis and cancer-associated bone loss.
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PMID:1'-Acetoxychavicol acetate inhibits RANKL-induced osteoclastic differentiation of RAW 264.7 monocytic cells by suppressing nuclear factor-kappaB activation. 1660 41

Glucocorticoids have been widely used in the treatment of multiple myeloma (MM) both as single agents and in combination with other drugs. However, primary or acquired glucocorticoid resistance occurs in most cases. It was recently reported that R-etodolac induced in vitro cytotoxicity in MM cell lines and in primary MM cells, as well as synergistically enhanced dexamethasone (Dex)-induced apoptosis in Dex-sensitive MM.1S cells. This study examined the in vitro and in vivo effects of combination treatment with R-etodolac and Dex on Dex-resistant OPM1 cells. Treatment with R-etodolac and Dex was found to enhance cytotoxicity, inhibit nuclear factor kappaB activity via upregulation of IkappaBalpha, as well as enhance Dex-induced caspase activation and poly (ADP)-ribose polymerase cleavage in OPM1 cells. R-etodolac also enhanced Dex cytotoxicity in patient MM cells that were resistant to glucocorticoids. The in vivo anti-tumour effect of this combination on MM cells was evaluated by using severe combined immunodeficient mice engrafted with OPM1. Treatment with R-etodolac or Dex alone did not induce a significant reduction of tumour volume; in contrast, combination treatment with R-etodolac and Dex induced significant synergistic inhibition of tumour growth. These data indicate that R-etodolac overcomes resistance to Dex in glucocorticoid-resistant MM cells, providing the framework for clinical trials of R-etodolac combined with Dex, to improve patient outcome in MM.
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PMID:In vivo and in vitro cytotoxicity of R-etodolac with dexamethasone in glucocorticoid-resistant multiple myeloma cells. 1680 65

Whether resveratrol, a component of red grapes, berries, and peanuts, could suppress the proliferation of multiple myeloma (MM) cells by interfering with NF-kappaB and STAT3 pathways, was investigated. Resveratrol inhibited the proliferation of human multiple myeloma cell lines regardless of whether they were sensitive or resistant to the conventional chemotherapy agents. This stilbene also potentiated the apoptotic effects of bortezomib and thalidomide. Resveratrol induced apoptosis as indicated by accumulation of sub-G(1) population, increase in Bax release, and activation of caspase-3. This correlated with down-regulation of various proliferative and antiapoptotic gene products, including cyclin D1, cIAP-2, XIAP, survivin, Bcl-2, Bcl-xL, Bfl-1/A1, and TRAF2. In addition, resveratrol down-regulated the constitutive activation of AKT. These effects of resveratrol are mediated through suppression of constitutively active NF-kappaB through inhibition of IkappaBalpha kinase and the phosphorylation of IkappaBalpha and of p65. Resveratrol inhibited both the constitutive and the interleukin 6-induced activation of STAT3. When we examined CD138(+) plasma cells from patients with MM, resveratrol inhibited constitutive activation of both NF-kappaB and STAT3, leading to down-regulation of cell proliferation and potentiation of apoptosis induced by bortezomib and thalidomide. These mechanistic findings suggest that resveratrol may have a potential in the treatment of multiple myeloma.
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PMID:Resveratrol inhibits proliferation, induces apoptosis, and overcomes chemoresistance through down-regulation of STAT3 and nuclear factor-kappaB-regulated antiapoptotic and cell survival gene products in human multiple myeloma cells. 1716 50

The MUC1 oncoprotein is aberrantly expressed in human multiple myeloma cells by mechanisms that are not understood. Moreover, the functional role of MUC1 in multiple myeloma is not known. The present studies demonstrate that the MUC1 gene locus is amplified in multiple myeloma cell lines and in primary cells from patients. The KMS28PE multiple myeloma cell line, which was found to have MUC1 gene amplification, was stably silenced for MUC1 using different siRNAs. Silencing MUC1 was associated with a decrease in nuclear beta-catenin levels, consistent with the function of MUC1 in stabilizing beta-catenin. MUC1 is also known to activate the IKKbeta-->NF-kappaB pathway and KMS28PE cells silenced for MUC1 were found to have downregulation of IKKbeta and IkappaBalpha phosphorylation, and decreased nuclear targeting of NF-kappaB p65. The results also demonstrate that MUC1: i) contributes to KMS28PE cell proliferation, and ii) protects against apoptosis and loss of self-renewal in the response to melphalan and dexamethasone. These findings indicate that MUC1 activates the beta-catenin and NF-kappaB pathways in multiple myeloma cells and contributes to their growth and survival.
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PMID:MUC1 oncoprotein promotes growth and survival of human multiple myeloma cells. 1857 61

Simvastatin, an inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase, is a cholesterol-lowering drug that may play a role in bone metabolism through a mechanism that is not fully understood. Recently, receptor activator of NF-kappaB ligand (RANKL), a member of the TNF superfamily, has emerged as a major mediator of bone loss via activation of osteoclastogenesis. The latter is also associated with certain cancers such as multiple myeloma and breast cancer. Whether simvastatin can modulate RANKL-induced or cancer induced osteoclastogenesis was investigated. The effect of simvastatin on RANKL signaling and consequent osteoclastogenesis was investigated. RANKL induced NF-kappaB activation, whereas pretreatment with simvastatin completely suppressed such activation and correlated with suppression of RANKL-induced activation of IkappaBalpha kinase, IkappaBalpha phosphorylation and IkappaBalpha degradation. Similarly, RANKL induced the differentiation of monocytic cells to osteoclasts, whereas simvastatin suppressed it. The inhibition was maximal when cells were exposed to both simvastatin and RANKL simultaneously and minimal when simvastatin was added 1 day after RANKL treatment. Simvastatin also inhibited the osteoclastogenesis induced by human breast cancer and by multiple myeloma cells. Together, our results indicate that simvastatin inhibits the RANKL-induced NF-kappaB activation pathway that leads to suppression of osteoclastogenesis induced by RANKL and by tumor cells, thereby suggesting its therapeutic potential in osteoporosis and in cancer-related bone loss.
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PMID:Simvastatin, 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, suppresses osteoclastogenesis induced by receptor activator of nuclear factor-kappaB ligand through modulation of NF-kappaB pathway. 1868 62

Anti-apoptotic pathways play a central role in the survival of multiple myeloma cells. The contribution of PI3-kinase and Akt kinase in mediating myeloma cell survival is well established although the role of glycogen synthase kinase-3 (GSK3) is less defined. In this study we determined the contribution of GSK3 in growth regulation of myeloma cells. We treated six different multiple myeloma cell lines with a Thiadiazolidinone (TDZD), a non-competitive inhibitor of GSK3 and determined its effects on proliferation and apoptosis. In addition we determined the activation of forkhead transcription factors (FOXO) in response to TDZD. TDZD inhibited proliferation and induced apoptosis of all myeloma cell lines. TDZD was also effective in inducing apoptosis of primary myeloma cells whereas CD34 positive normal hematopoietic cells were protected from apoptosis. Furthermore, TDZD-mediated inhibition of GSK3 resulted in dephosphorylation and activation of FOXO3a. In primary myeloma cells FOXO transcription factors were highly phosphorylated where as the levels of GSK3 phosphorylation was quite low. The levels of the pro-apoptotic proteins Fas ligand (FasL) and IkappaBalpha increased after treatment with TDZD in myeloma cell lines. These studies provide the basis for further testing of GSK3 inhibitors in the clinical setting.
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PMID:Growth control of multiple myeloma cells through inhibition of glycogen synthase kinase-3. 1872 64

Elevated Nuclear Factor kappaB (NFkappaB) levels have been reported in multiple myeloma cells derived from patients relapsing after chemotherapy. In the search of an in vitro a model with molecular features similar to relapsing lesions, we focused our attention on an IL-6 autocrine human myeloma cell line (U266), characterized by apoptosis resistance due to upregulation of two constitutive signaling pathways: NFkappaB and STAT-3. NFkappaB activity was inhibited with proteasome inhibitory agents, such as PS-341 and Withaferin A, with an IKK inhibitor (Wedelolactone) or with the adenoviral vector HD IkappaBalphamut-IRES-EGFP encoding a mutant IkappaBalpha protein, resistant to proteasomal degradation. We observed that the NFkappaB intracellular dislocation at the beginning of the treatment affected therapeutic effectiveness of PS-341, Withaferin A and Wedelolactone; interestingly, the adenoviral vector was highly effective in inducing apopotosis even with NFkappaB being predominantly nuclear at the time of infection. We also observed that U266 treated with the Interleukin-6 antagonist Sant7 exhibited reduced STAT3 activity and preferential cytoplasmic NFkappaB location; moreover they became capable of undergoing apoptosis mainly from the G1 phase. Adenoviral vector treated U266 have NFkappaB localized completely in the cytoplasm and also showed downregulation of nuclear phospho STAT-3. Finally, combined targeting of NFkappaB and STAT3 signalling pathways was the most effective treatment in inducing apoptosis. These findings suggest that combined NFkappaB and STAT3 targeting warrants further investigations in other apoptosis resistant MM cell lines as well as in suitable MM animal models.
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PMID:Simultaneous inhibition of the constitutively activated nuclear factor kappaB and of the interleukin-6 pathways is necessary and sufficient to completely overcome apoptosis resistance of human U266 myeloma cells. 1893 95

Xanthohumol (XN), a prenylated chalcone isolated from hop plant, exhibits anti-inflammatory, antiproliferative, and antiangiogenic properties through an undefined mechanism. Whether examined by intracellular esterase activity, phosphatidylserine externalization, DNA strand breaks, or caspase activation, we found that XN potentiated tumor necrosis factor-induced apoptosis in leukemia and myeloma cells. This enhancement of apoptosis correlated with down-regulation of nuclear factor-kappaB (NF-kappaB) survivin, bcl-xL, XIAP, cIAP1, cIAP2, cylin D1, and c-myc. XN down-regulated both constitutive and inducible NF-kappaB activation, inhibition of phosphorylation and degradation of IkappaBalpha, suppression of p65 nuclear translocation, and NF-kappaB-dependent reporter gene transcription. XN directly inhibited tumor necrosis factor-induced IkappaBalpha kinase (IKK) activation and a reducing agent abolished this inhibition, indicating the role of cysteine residue. XN had no effect on the IKK activity when cysteine residue 179 of IKK was mutated to alanine. XN also directly inhibited binding of p65 to DNA, a reducing agent reversed this effect, and mutation of cysteine residue 38 to serine of p65 abolished this effect. Thus, our results show that modification of cysteine residues of IKK and p65 by XN leads to inhibition of the NF-kappaB activation pathway, suppression of antiapoptotic gene products, and potentiation of apoptosis in leukemia cells.
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PMID:Modification of the cysteine residues in IkappaBalpha kinase and NF-kappaB (p65) by xanthohumol leads to suppression of NF-kappaB-regulated gene products and potentiation of apoptosis in leukemia cells. 2364 Sep 98

Receptor activator of nuclear factor-kappaB (NF-kappaB) ligand (RANKL) has emerged as a major mediator of bone resorption, commonly associated with cancer and other chronic inflammatory diseases. Inhibitors of RANKL signaling thus have potential in preventing bone loss. In the present report, the potential of zerumbone, a sesquiterpene derived from subtropical ginger, to modulate osteoclastogenesis induced by RANKL and breast cancer was examined. We found that zerumbone inhibited RANKL-induced NF-kappaB activation in mouse monocyte, an osteoclast precursor cell, through inhibition of activation of IkappaBalpha kinase, IkappaBalpha phosphorylation, and IkappaBalpha degradation. Zerumbone also suppressed RANKL-induced differentiation of these cells to osteoclasts. This sesquiterpene also inhibited the osteoclast formation induced by human breast tumor cells and by multiple myeloma cells. Finally, we examined whether zerumbone could prevent human breast cancer-induced bone loss in animals. We found that zerumbone decreased osteolysis in a dose-dependent manner in MDA-MB-231 breast cancer tumor-bearing athymic nude mice. These results indicate that zerumbone is an effective blocker of RANKL-induced NF-kappaB activation and of osteoclastogenesis induced by RANKL and tumor cells, suggesting its potential as a therapeutic agent for osteoporosis and cancer-associated bone loss.
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PMID:Zerumbone abolishes RANKL-induced NF-kappaB activation, inhibits osteoclastogenesis, and suppresses human breast cancer-induced bone loss in athymic nude mice. 3018 10

Proteasome inhibitors represent a promising therapy for the treatment of relapsed and/or refractory multiple myeloma, a disease that is concomitant with osteolysis and enhanced osteoclast formation. While blockade of the proteosome pathway has been recently shown to influence osteoclast formation and function, the precise molecular cascade underlying these effects is presently unclear. Here, we provide evidence that proteasome inhibitors directly impair osteoclast formation and function via the disruption of key RANK-mediated signaling cascades. Disruption of the proteosome pathway using selective inhibitors (MG-132, MG-115, and epoxomicin) resulted in the accumulation of p62 and CYLD, and altered the subcellular targeting and distribution of p62 and TRAF6 in osteoclast-like cells. Proteosome inhibition also blocked RANKL-induced NF-kappaB activation, IkappaBalpha degradation and nuclear translocation of p65. The disruption in RANK-signaling correlated dose-dependently with an impairment in osteoclastogenesis, with relative potency epoxomicin > MG-132 > MG-115 based on equimolar concentrations. In addition, these inhibitors were found to impact osteoclastic microtubule organization and attenuate bone resorption. Based on these data we propose that deregulation of key RANK-mediated signaling cascades (p62, TRAF6, CYLD, and IkappaBalpha) underscores proteasome-mediated inhibition of osteolytic bone conditions.
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PMID:Proteasome inhibitors impair RANKL-induced NF-kappaB activity in osteoclast-like cells via disruption of p62, TRAF6, CYLD, and IkappaBalpha signaling cascades. 1936 10


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