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)

The proteasome has been regarded as a major target for antitumor therapy in selected tumor types (i.e., multiple myeloma). Available evidence suggests that targeting the proteasome with selective compounds can represent an excellent approach for modulating the response to antitumor agents including both conventional cytotoxic agents and target-specific agents. In fact, promising drug interaction data showing synergistic effects have been reported in cellular studies, both in multiple myeloma and in solid tumors. The mechanistic bases of improved efficacy of drug combinations including bortezomib or other proteasome inhibitors and conventional cytotoxic agents have been in part unravelled and involve the capability of proteasome inhibitors to interfere with the stability of the targets of cytotoxic agents (e.g., topoisomerase inhibitors) as well as with cellular protective pathways (e.g., DNA repair and NF-kB-regulated gene expression). Moreover, the synergistic interaction of proteasome inhibitors and target-specific agents implicates a variety of mechanisms linked to the specific target (e.g., histone deacetylase) modulated by the tailored drug used in combination with the proteasome inhibitor. Several clinical studies are ongoing in an attempt to define drug combination approaches that enhance the efficacy of antitumor treatments. Considering the fast moving field of preclinical research regarding proteasome inhibition, a major contribution to the understanding of the bases of tumor response to treatment with proteasome inhibitors is expected.
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PMID:Drug combinations with proteasome inhibitors in antitumor therapy. 2318 71

Modulation of the antitumor immune response through the engagement of NKG2D receptors with their ligands (L) on targets represents a promising therapeutic approach against cancer. In this study, we tested the effect of valproic acid (VPA), a histone deacetylase (HDAC) inhibitor, on the expression of NKG2D ligands in myeloma cells. We demonstrated that VPA was able to upregulate both protein and mRNA expression of major histocompatibility complex class I-related chain (MIC) A/B and UL16-binding protein (ULBP) 2 without any significant effect on the expression of ULBP1, ULBP3, and ULBP4 or induction of other natural killer (NK) cell ligands, such as NKp30-L, NKp44-L, and NKp46-L in myeloma cells. A (51)Cr release assay and degranulation assay indicated that the induction of MICA/B and ULBP2 augmented NK cell-mediated lysis of myeloma cells, which was abolished by the addition of a blocking NKG2D antibody. Activation of constitutively phosphorylated extracellular signal-regulated kinase (ERK) by VPA is essential for the up-regulation of MICA/B and ULBP2 expressions. Inhibition of ERK using ERK inhibitor PD98059 decreased both MICA/B and ULBP2 expressions and NK cell cytotoxicity. Furthermore, overexpression of constitutively active ERK in ARK resulted in increased MICA/B and ULBP2 expressions and enhanced NK cell lysis. These data indicate that increased sensitivity of VPA-treated myeloma cells to NK cell lysis is caused by higher NKG2D ligand expression, resulting from more active ERK signaling pathway. Our results provide evidence that targeting ERK signaling pathway may be an additional mechanism supporting the antimyeloma activity of HDAC inhibitors and suggest its possible immunotherapeutic value for myeloma treatment.
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PMID:Valproic acid upregulates NKG2D ligand expression through an ERK-dependent mechanism and potentially enhances NK cell-mediated lysis of myeloma. 2330 50

Bendamustine, a hybrid molecule of purine analog and alkylator, induces cell death by activation of apoptosis, DNA damage response, and mitotic catastrophe. Entinostat, a selective class I inhibitor of histone deacetylase (HDAC), exerts anti-tumor activity in various cancer types, including multiple myeloma (MM). We sought to determine the combinatorial effects of bendamustine and entinostat on MM cells. Cell growth assays showed that bendamustine or entinostat inhibited proliferation in a dose-dependent manner, and their combinations synergistically induced growth inhibition in all MM cells tested. An apoptotic-ELISA and western blot assays on PARP cleavage and caspase-8 and caspase-3 revealed that bendamustine in combination with entinostat exhibited a much more potent activity than either agent alone to promote the MM cells undergoing apoptosis in a dose-dependent manner. Flow cytometric analysis found that entinostat exhibited distinct effects on cell cycle progression in different lines and bendamustine mainly arrested the cells at S phase, whereas their combinations dramatically blocked the S cells entering G2/M phase. Furthermore, studies on DNA damage response indicated that phospho-histone H2A.X (P-H2A.X), a hall marker of DNA double strand break, along with phosphorylated CHK2 (P-CHK2) was significantly enhanced by the combinations of bendamustine and entinostat as compared to either agent alone. These molecular changes were correlated with the increases in mitotic catastrophe. Collectively, our data demonstrate that bendamustine in combination with entinostat exhibit potent anti-proliferative/anti-survival activity in MM cells via induction of apoptosis and DNA damage response. Regimens consisting of bendamustine and/or entinostat may represent novel therapeutic strategies against MM.
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PMID:Combination of bendamustine and entinostat synergistically inhibits proliferation of multiple myeloma cells via induction of apoptosis and DNA damage response. 2345 96

Histone lysine acetylation is regulated by both histone deacetylases (HDACs) and histone acetyl transferases. Inhibition of deacetylases induces hyperacetylate of target proteins and has a crucial role in the epigenetic regulation of gene expression mediating cell survival and proliferation. Therefore, HDAC inhibitors have emerged as novel therapeutic agents for cancers, including multiple myeloma (MM). Recent studies revealed that HDAC inhibitors trigger hyperacetylation of not only histones, but also non-histone proteins regulating cell growth and survival, revealing the complexity of mechanism of action of HDAC inhibitors. Many HDAC inhibitors have already shown significant anti-MM activities in preclinical studies and are under evaluation in clinical trials.
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PMID:Histone deacetylase inhibitors in the treatment for multiple myeloma. 2347 57

Multiple myeloma is a hematologic malignancy characterized by the proliferation of neoplastic plasma cells in the bone marrow. Although the first-to-market proteasome inhibitor bortezomib (Velcade) has been successfully used to treat patients with myeloma, drug resistance remains an emerging problem. In this study, we identify signatures of bortezomib sensitivity and resistance by gene expression profiling (GEP) using pairs of bortezomib-sensitive (BzS) and bortezomib-resistant (BzR) cell lines created from the Bcl-XL/Myc double-transgenic mouse model of multiple myeloma. Notably, these BzR cell lines show cross-resistance to the next-generation proteasome inhibitors, MLN2238 and carfilzomib (Kyprolis) but not to other antimyeloma drugs. We further characterized the response to bortezomib using the Connectivity Map database, revealing a differential response between these cell lines to histone deacetylase (HDAC) inhibitors. Furthermore, in vivo experiments using the HDAC inhibitor panobinostat confirmed that the predicted responder showed increased sensitivity to HDAC inhibitors in the BzR line. These findings show that GEP may be used to document bortezomib resistance in myeloma cells and predict individual sensitivity to other drug classes. Finally, these data reveal complex heterogeneity within multiple myeloma and suggest that resistance to one drug class reprograms resistant clones for increased sensitivity to a distinct class of drugs. This study represents an important next step in translating pharmacogenomic profiling and may be useful for understanding personalized pharmacotherapy for patients with multiple myeloma.
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PMID:Profiling bortezomib resistance identifies secondary therapies in a mouse myeloma model. 2353 25

Myeloma therapy has undergone significant advances in recent years resulting in a marked improvement in survival. Knowledge of the active pathways involved in myeloma pathogenesis has led to the discovery of novel agents and greatly expanded the potential armamentarium available for treatment. This better understanding of the disease and resistance mechanisms has resulted in new agent classes that are being evaluated in preclinical and early clinical studies. In addition, dosing for existing agents is being optimized, and they are being given in new combinations. In this article, we review experimental agents that are showing promise in multiple myeloma treatment. New biological agents in clinical trials hold the promise of efficacy through novel mechanisms of action, with a significant reduction of dose-limiting toxicities compared with classic cytotoxic chemotherapeutics. Second-generation proteasome inhibitors and immunomodulatory agents are furthest along in clinical development, and histone deacetylase inhibitors, heat shock protein 90 inhibitors, Akt inhibitors and monoclonal antibodies are some of the other agents entering later-phase clinical trials. We also review developments in targeting the myeloma stem cell as an exciting new treatment direction.
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PMID:Experimental approaches in the treatment of multiple myeloma. 2355 91

Clinical outcomes for patients with multiple myeloma (MM) have improved substantially since the introduction of novel agents including the proteasome inhibitor bortezomib and the immunomodulatory drugs thalidomide and lenalidomide. However, most patients with MM eventually relapse, and prognosis remains poor among patients with relapsed and/or refractory disease. Combination therapy using agents with different mechanisms of action is emerging as an attractive treatment approach in oncology to increase efficacy and/or overcome resistance to standard treatment regimens. This review discusses unmet needs in the treatment of MM and the development of histone deacetylase inhibitors as a treatment modality for MM.
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PMID:The role of histone deacetylase inhibitors in patients with relapsed/refractory multiple myeloma. 2361 65

Multiple myeloma (MM) refractory to both proteasome inhibitors and immunomodulatory agents (IMiDs; double-refractory myeloma) has a poor prognosis. With the more frequent use of these agents as part of initial therapy, and then in the maintenance setting until disease progression, such drug resistance is an emerging problem of great significance. New therapeutic strategies are clearly needed for this patient population, including the development of more potent agents within existing antimyeloma drug classes, exploration of rational combinations of both novel and conventional drugs, and validation of new myeloma drug targets. Several approaches have shown substantial promise, including use of the second-generation proteasome inhibitor carfilzomib and the third-generation IMiD pomalidomide, which led to the recent regulatory approval of both agents. In addition, the kinesin-spindle protein KSP inhibitor ARRY-520 has shown activity as a first-in-class drug in myeloma therapeutics, whereas the histone deacetylase (HDAC) inhibitors vorinostat and panobinostat have demonstrated efficacy when used in rational combinations. This overview provides a summary of novel agents that have shown activity in double-refractory myeloma in recent phase II and III clinical trials, and a framework for future studies that will help to improve outcomes in this patient population.
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PMID:Novel approaches to treatment of double-refractory multiple myeloma. 2371 30

Multiple myeloma (MM) arises from abnormal proliferation and survival (ie, a high proliferative index and a low apoptotic index) of mature immunoglobulin-producing plasma cells in the bone marrow. Development of novel therapeutic options, such as proteasome inhibitors and immunomodulatory agents (IMiDs), has improved treatment outcomes. However, patients often develop relapsed and refractory MM, thus requiring alternative treatment approaches. Histone acetyltransferases and histone deacetylases (HDACs) control the acetylation status of proteins and affect a broad array of physiologic processes (eg, cell cycle, apoptosis, and protein folding) involved in cell growth and survival. The discovery that HDACs might have a role in various hematologic malignancies, including MM, has led to the development of HDAC inhibitors as potential antitumor agents. Preclinical evidence from studies of HDAC inhibitors in combination with proteasome inhibitors (eg, bortezomib and carfilzomib), other antimyeloma agents, including IMiDs (eg, lenalidomide), and cytotoxic agents (eg, melphalan, pegylated liposomal doxorubicin), provides a strong scientific rationale for the evaluation of these regimens. Results from early stage clinical trials further support the use of HDAC inhibitors as a therapeutic option for MM, in combination with current and emerging antimyeloma agents. In this review, we examine the role of protein acetylation that underlies the antimyeloma effects of HDAC inhibitors, discuss the preclinical rationale for the use of HDAC inhibitors in combination with other antimyeloma agents, and provide an overview of the current clinical evidence supporting the use of HDAC inhibitors as a therapeutic option in MM.
Clin Lymphoma Myeloma Leuk 2013 Aug
PMID:Histone deacetylase inhibitors in multiple myeloma: rationale and evidence for their use in combination therapy. 2378 22

The treatment of multiple myeloma has evolved significantly over the past 2 decades due to the use of high-dose chemotherapy and autologous stem cell transplantation, and the subsequent introduction of the immunomodulatory agents (thalidomide and lenalidomide) and the proteasome inhibitor (bortezomib). The median overall survival of multiple myeloma patients has increased significantly with patients younger than age 50 years experiencing a 10-year survival rate of around 40%. However, despite the increased effectiveness of the first-line agents, the majority of patients will eventually relapse and become drug resistant. Promising novel therapies have recently emerged and are being used to treat relapsed and refractory patients. This review will cover the clinical data regarding these emergent therapies that include new generation of proteasome inhibitors (carfilzomib, ixazomib, oprozomib, and marizomib), immunomodulatory drugs (pomalidomide), monoclonal antibodies (elotuzumab and daratumumab), signal transduction modulator (perifosine), and histone deacetylase inhibitors (vorinostat and panobinostat).
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PMID:Emerging therapies in multiple myeloma. 2393 33


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