Ticagrelor Modulates Proliferation in Multiple Myeloma Via P1 and P2 Receptor-Mediated Mechanisms

Abstract Background:Multiple Myeloma (MM) is a hematologic malignancy involving uncontrolled proliferation of plasma cells and is particularly trophic to bone where it induces osteoclast-mediated bone destruction. Ticagrelor is a platelet inhibitor that blocks P2Y12 receptors and inhibits ENT1-mediated adenosine uptake, thereby increasing extracellular adenosine, which activates P1 receptors. Prior studies demonstrate that ticagrelor increases life span in a murine model of MM via its effect on extracellular adenosine. Prior studies also demonstrate an increase in proliferation, in vitro, and tumor growth, in vivo, of MM cells in the presence of platelet releasate. Ticagrelor blocks in vitro platelet-stimulated myeloma proliferation, suggesting a positive relationship and interaction between active platelets and multiple myeloma. We therefore determined whether the effect of ticagrelor on myeloma cells was mediated by extra-cellular adenosine or/and inhibition of platelet function. Methods:Human primary myeloma cells (KMS) were incubated with ticagrelor (10-9-10-4 M) in the presence of 5ng/ml IL-6 in the absence/presence of an A2AR antagonist (ZM241385 10-6M) and platelets (1:500 myeloma cell:platelets). In other experiments MM cells were incubated in the presence of platelet releasate, releasate from platelets treated with ticagrelor, or ticagrelor alone. Proliferation was assayed by Cell Titer MTS assay (Promega). Results: Ticagrelor inhibited MM cell proliferation by 20% (p<0.0001, IC50=0.5µM). This effect was abrogated by ZM241385 (48±6% increased vs. ticagrelor, p<0.0001). Platelet releasate increased MM proliferation by 33±6% (p<0.05) and ticagrelor inhibited the effect of platelet releasate on MM cell proliferation (IC50=0.12µM). Conclusions:These results suggest that ticagrelor inhibits proliferation of malignant plasma cells by a mechanism dependent on both adenosine A2A and platelet P2Y12 receptors. Moreover, platelet releasate intensifies proliferation, and this effect is reversed when the P2Y12 receptor is blocked by ticagrelor. Figure 1 Figure 1. Figure 2 Figure 2. Figure 3 Figure 3. Disclosures Meltzer: NIH: Research Funding; Celgene: Research Funding; AstraZeneca: Research Funding. Mediero:AstraZeneca: Research Funding; Celgene: Research Funding; NIH: Research Funding. Whatling:AstraZeneca: Employment. Berger:Merck: Membership on an entity's Board of Directors or advisory committees; AZ: Research Funding. Cronstein:AstraZeneca: Consultancy, Research Funding; CanFite: Equity Ownership; Gizmo Therapeutics: Consultancy; Eli Lilly & Co.: Consultancy; NIH: Research Funding; Celgene: Research Funding.

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CD38-Targeted Immunochemotherapy Of Multiple Myeloma: Preclinical Evidence For Its Combinatorial Use In Lenalidomide and Bortezomib Refractory/Intolerant MM Patients

Blood ◽

10.1182/blood.v122.21.277.277 ◽

2013 ◽

Vol 122 (21) ◽

pp. 277-277 ◽

Cited By ~ 3

Author(s):

Inger S. Nijhof ◽

Willy A. Noort ◽

Jeroen Lammerts van Bueren ◽

Berris van Kessel ◽

Joost M. Bakker ◽

...

Keyword(s):

Multiple Myeloma ◽

Research Funding ◽

Plasma Cells ◽

Cell Lysis ◽

In Vitro Assays ◽

Human Antibody ◽

Myeloma Cells ◽

Clinical Phase

Abstract Multiple myeloma (MM) remains an incurable malignancy of clonal plasma cells. Although the new generation of immunomodulatory agents, such as lenalidomide (LEN), and the potent proteasome inhibitor bortezomib (BORT) have significantly improved the overall survival of MM patients, all chemotherapy strategies are eventually hampered by the development of drug-resistance. The outcome of patients who are refractory to thalidomide, lenalidomide (LEN) and bortezomib (BORT) is very poor. Set out with the idea that targeted immunotherapy with human antibodies may offer new perspectives for MM patients, we have recently developed daratumumab (DARA), a CD38 human antibody with broad-spectrum killing activity, mainly via ADCC (antibody dependent cellular cytotoxicity) and CDC (complement dependent cytotoxicity). In our previous preclinical studies and in current clinical phase I/II trials, DARA induces marked anti-MM activity. Based on these encouraging results, we now explored the potential activity of DARA for patients who are refractory to LEN- and/or BORT. In a recently developed human-mouse hybrid model that allows the in vivo engraftment and outgrowth of patient-derived primary myeloma cells in immune deficient Rag2-/-gc-/- mice, single dose DARA treatment appeared to effectively inhibit the malignant expansion of primary MM cells derived from a LEN- and BORT-refractory patient, indicating the potential efficacy of DARA even in LEN/BORT refractory patients. To substantiate the conclusions of these in vivo data, we conducted in vitro assays, in which full BM-MNCs from LEN (n=11) and LEN/BORT (n=8) refractory patients were treated with DARA alone or the combination of DARA with LEN or BORT to induce MM cell lysis. As expected, LEN alone induced no or little lysis of MM cells in the LEN-refractory patients and also BORT was not able to induce any lysis in the BORT-refractory patients. On the contrary, DARA induced substantial levels of MM cell lysis in all LEN and LEN/BORT-refractory patients. This lysis was significantly enhanced by combination with LEN or BORT. The combination of DARA and BORT improved MM lysis by additive mechanisms. However, LEN improved DARA-mediated lysis of MM cells in a synergistic manner through the activation of effector cells involved in DARA-mediated ADCC. In conclusion, our results demonstrate that DARA is also effective against multiple myeloma cells derived from LEN- and BORT-refractory patients. Especially LEN seems to improve responses in a synergistic manner. Our results provide a rationale for clinical evaluation of DARA in combination with LEN to achieve more effective results in LEN- and BORT-refractory patients. Disclosures: Lammerts van Bueren: Genmab: Employment. Bakker:Genmab: Employment. Parren:Genmab: Employment. van de Donk:Celgene: Research Funding. Lokhorst:Genmab A/S: Consultancy, Research Funding; Celgene: Honoraria; Johnson-Cilag: Honoraria; Mudipharma: Honoraria.

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Osteoprotegerin is bound, internalized, and degraded by multiple myeloma cells

Blood ◽

10.1182/blood-2002-04-1190 ◽

2002 ◽

Vol 100 (8) ◽

pp. 3002-3007 ◽

Cited By ~ 165

Author(s):

Therese Standal ◽

Carina Seidel ◽

Øyvind Hjertner ◽

Torben Plesner ◽

Ralph D. Sanderson ◽

...

Keyword(s):

Multiple Myeloma ◽

Bone Disease ◽

Plasma Cells ◽

Hematologic Malignancy ◽

Bone Destruction ◽

Nuclear Factor Κb ◽

Heparin Binding ◽

Bone Homeostasis ◽

Myeloma Cells ◽

Heparan Sulfates

Multiple myeloma (MM) is a hematologic malignancy characterized by accumulation of plasma cells in the bone marrow (BM). Bone destruction is a complication of the disease and is usually associated with severe morbidity. The balance between receptor activator of nuclear factor-κB (NF-κB) ligand and osteoprotegerin (OPG) is of major importance in bone homeostasis. We have recently shown that serum OPG levels are lower in patients with myeloma than in healthy individuals. Here we show that myeloma cells can bind, internalize, and degrade OPG, thereby providing a possible explanation for the lower levels of OPG in the BM of patients with MM. This process is dependent on interaction of OPG with heparan sulfates on the myeloma cells. The results suggest a novel biologic mechanism for the bone disease associated with MM and that treatment of the bone disease with OPG lacking the heparin-binding domain should be considered.

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Bortezomib Protects Osteoblasts from Glucocorticoid-Induced Damage, and Enhances Glucocorticoid-Induced Toxicity Against Osteoclasts and Myeloma Cells.

Blood ◽

10.1182/blood.v110.11.3523.3523 ◽

2007 ◽

Vol 110 (11) ◽

pp. 3523-3523

Author(s):

Kent Soe ◽

Thomas L. Andersen ◽

Katarzyna Kupisiewicz ◽

Torben Plesner ◽

Jean-Marie Delaisse

Keyword(s):

Multiple Myeloma ◽

Bone Repair ◽

Plasma Cells ◽

Bone Cells ◽

Negative Impact ◽

Bone Destruction ◽

Myeloma Cells ◽

The Impact ◽

Human Osteoclasts

Abstract Introduction: Multiple myeloma is characterized by the accumulation of malignant plasma cells in the bone marrow, and leads most often to bone destruction by osteoclasts and prevention of bone repair by osteoblasts. Bortezomib and glucocorticoids are both powerful anti-myeloma drugs that are used for killing malignant plasma cells in the patients. Furthermore bortezomib has direct anti-osteoclastic and pro-osteoblastic properties that may contribute to bone protection in multiple myeloma, while glucocorticoids have more ambiguous effects on these bone cells and are clearly anti-osteoblastic. Recent clinical trials based on the combination of bortezomib and glucocorticoids drew the attention on the very promising anti-myeloma efficiency of this combination. However, the bone cell response of this combination has not been tested. In order to address this question, we performed an in vitro study, and importantly adapted our in vitro model to mimic the pharmacokinetics of bortezomib and glucocorticoid in the patients. Methods: Myeloma cell lines, primary human osteoclasts and osteoblast-like cells (MC3T3) were pulse-treated or not with clinically relevant doses of bortezomib (12.5, 25 or 50 nM) for 3 hours. Subsequently, the cells were exposed during a 3-day culture to 1.6 μM prednisolone which approximately corresponds to a dose of 50 mg prednisolone in a patient. The impact of the treatment on the cells was determined by survival, activity and gene expression. Results: Bortezomib as a single treatment was very efficient in killing sensitive myeloma cells (OPM2) whereas the more resistant cells (U266) were more efficiently killed in combination with prednisolone. The release of TRAP from primary human osteoclasts, a marker of osteoclastic activation, was strongly inhibited by bortezomib treatment alone, but only in combination with prednisolone did it result in killing of osteoclasts. Survival of osteoblast like cells was uninfluenced by treatment with bortezomib alone. In contrast, as shown previously, prednisolone strongly reduced osteoblast survival. Most importantly however, a 3 hr pre-treatment with bortezomib protected the osteoblasts against the detrimental effects of glucocorticoids. Ongoing investigations by Q-PCR indicate that important markers of osteoblast maturation remain high if the osteoblasts were pre-treated with bortezomib prior to prednisolone exposure. Conclusion: Our study demonstrates in conditions relevant to treatment of myeloma patients, that combining bortezomib and glucocorticoids has a direct synergistic effect against myeloma cells and osteoclasts, and that bortezomib protects directly osteoblasts from the negative impact of glucocorticoids. Thus, the combination of bortezomib and glucocorticoids is not only a powerful treatment of multiple myeloma itself, but also shows promise for treating myeloma bone disease.

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Hypoxia-induced CREB cooperates MMSET to modify chromatin and promote DKK1 expression in multiple myeloma

Oncogene ◽

10.1038/s41388-020-01590-8 ◽

2021 ◽

Author(s):

Yinyin Xu ◽

Jing Guo ◽

Jing Liu ◽

Ying Xie ◽

Xin Li ◽

...

Keyword(s):

Multiple Myeloma ◽

Combined Treatment ◽

Hypoxia Inducible Factor ◽

Bone Destruction ◽

Bone Lesions ◽

Myeloma Cells ◽

Downstream Target ◽

Dkk1 Expression

AbstractMyeloma cells produce excessive levels of dickkopf-1 (DKK1), which mediates the inhibition of Wnt signaling in osteoblasts, leading to multiple myeloma (MM) bone disease. Nevertheless, the precise mechanisms underlying DKK1 overexpression in myeloma remain incompletely understood. Herein, we provide evidence that hypoxia promotes DKK1 expression in myeloma cells. Under hypoxic conditions, p38 kinase phosphorylated cAMP-responsive element-binding protein (CREB) and drove its nuclear import to activate DKK1 transcription. In addition, high levels of DKK1 were associated with the presence of focal bone lesions in patients with t(4;14) MM, overexpressing the histone methyltransferase MMSET, which was identified as a downstream target gene of hypoxia-inducible factor (HIF)-1α. Furthermore, we found that CREB could recruit MMSET, leading to the stabilization of HIF-1α protein and the increased dimethylation of histone H3 at lysine 36 on the DKK1 promoter. Knockdown of CREB in myeloma cells alleviated the suppression of osteoblastogenesis by myeloma-secreted DKK1 in vitro. Combined treatment with a CREB inhibitor and the hypoxia-activated prodrug TH-302 (evofosfamide) significantly reduced MM-induced bone destruction in vivo. Taken together, our findings reveal that hypoxia and a cytogenetic abnormality regulate DKK1 expression in myeloma cells, and provide an additional rationale for the development of therapeutic strategies that interrupt DKK1 to cure MM.

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Identification of the Cysteine Protease Legumain as a Potential Chronic Hypoxia-Specific Multiple Myeloma Target Gene

Cells ◽

10.3390/cells11020292 ◽

2022 ◽

Vol 11 (2) ◽

pp. 292

Author(s):

Ada-Sophia Clees ◽

Verena Stolp ◽

Björn Häupl ◽

Dominik C. Fuhrmann ◽

Frank Wempe ◽

...

Keyword(s):

Multiple Myeloma ◽

Cysteine Protease ◽

Chronic Hypoxia ◽

Plasma Cells ◽

Hematologic Malignancy ◽

Low Oxygen ◽

Clonal Proliferation ◽

Temporal Adaptation ◽

Specific Regulation

Multiple myeloma (MM) is the second most common hematologic malignancy, which is characterized by clonal proliferation of neoplastic plasma cells in the bone marrow. This microenvironment is characterized by low oxygen levels (1–6% O2), known as hypoxia. For MM cells, hypoxia is a physiologic feature that has been described to promote an aggressive phenotype and to confer drug resistance. However, studies on hypoxia are scarce and show little conformity. Here, we analyzed the mRNA expression of previously determined hypoxia markers to define the temporal adaptation of MM cells to chronic hypoxia. Subsequent analyses of the global proteome in MM cells and the stromal cell line HS-5 revealed hypoxia-dependent regulation of proteins, which directly or indirectly upregulate glycolysis. In addition, chronic hypoxia led to MM-specific regulation of nine distinct proteins. One of these proteins is the cysteine protease legumain (LGMN), the depletion of which led to a significant growth disadvantage of MM cell lines that is enhanced under hypoxia. Thus, herein, we report a methodologic strategy to examine MM cells under physiologic hypoxic conditions in vitro and to decipher and study previously masked hypoxia-specific therapeutic targets such as the cysteine protease LGMN.

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Kinome-Wide RNAi Studies in Human Multiple Myeloma Identify a Lymphoid Restricted Kinase GRK6 as a Selectively Vulnerable Target That Regulates STAT3/MCL1.

Blood ◽

10.1182/blood.v114.22.601.601 ◽

2009 ◽

Vol 114 (22) ◽

pp. 601-601

Author(s):

Rodger E. Tiedemann ◽

Yuan Xiao Zhu ◽

Jessica Schmidt ◽

Hongwei Yin ◽

Quick Que ◽

...

Keyword(s):

Multiple Myeloma ◽

Epithelial Cells ◽

Tumor Cells ◽

Research Funding ◽

Kinase Inhibitors ◽

Lymphoid Tissues ◽

Myeloma Cells ◽

Stat3 Phosphorylation ◽

Human Multiple Myeloma

Abstract Abstract 601 A paucity of validated kinase targets in human multiple myeloma (MM) has delayed clinical deployment of kinase inhibitors in treatment strategies. We therefore conducted a kinome-wide small interfering RNA (siRNA) lethality study in MM tumor lines bearing common t(4;14), t(14;16) and t(11;14) translocations to identify critically vulnerable kinases in MM tumor cells without regard to preconceived mechanistic notions. Primary screening was performed in duplicate using an 1800-oligo siRNA library in a single-siRNA-per-well format. siRNA were transfected at low concentration (13nM) to minimize off-target effects using conditions that resulted in transfection of >95% cells and <5% background cytotoxicity. After 96 hours, viability was measured by ATP-dependent luminescence. Fifteen kinases were consistently vulnerable in MM cells, including AKT1, AK3L1, AURKA, AURKB, CDC2L1, CDK5R2, FES, FLT4, GAK, GRK6, HK1, PKN1, PLK1, SMG1, and TNK2. While several kinases (PLK1, HK1) were equally vulnerable in epithelial cells, others and particularly the G-protein coupled receptor kinase, GRK6, appeared selectively vulnerable in MM. GRK6 inhibition is selectively lethal to KMS11, OPM1, H929, KMS18 and OCI-MY5 myeloma cells and has minimal effect on 293, MCF7, SF767, A375 or A549 epithelial cells. Persistent expression of FLAG-GRK6 via cDNA rescued KMS11 cells from the lethal effect of a 3'UTR-targeted GRK6 siRNA, but not from control siRNA, validating identification of GRK6 as an essential myeloma survival kinase. Furthermore, concordant results were obtained using four different exon-based GRK6 siRNA, all of which induced GRK6 silencing and similar inhibition of KMS11 proliferation and viability. Significantly, GRK6 is ubiquitously expressed in lymphoid tissues and myeloma, but by comparison appears absent or only weakly expressed in most primary human somatic tissues. From co-immunoprecipitation experiments we demonstrate that GRK6 is highly expressed in myeloma cells via direct association with the HSP90 chaperone. Inhibition of HSP90 with geldanamycin blocks GRK6 protein expression. Importantly, direct GRK6 silencing causes rapid and selective suppression of STAT3 phosphorylation that is associated with sustained reductions in total MCL1 protein levels and MCL1 phosphorylation (within 24 hours), providing a potent mechanism for the cytotoxicity of GRK6 inhibition in MM tumor cells. GF109203X is an inhibitor of both protein kinase C and of GRK6 that causes near total inhibition of these kinases in vitro at distinct concentrations of 0.1μM and 1-10μM respectively. Notably, GF109203X was substantially cytotoxic to 10/14 myeloma tumor lines at concentrations most consistent with GRK6 inhibition (5-20μM), and was selectively more cytotoxic to myeloma tumor cells than to non-myeloma cell lines (P=0.01), highlighting the potential of GRK6 as a pharmaceutical target for selective therapeutic intervention in myeloma. As mice that lack GRK6 are healthy, inhibition of GRK6 represents a uniquely targeted novel therapeutic strategy in human multiple myeloma. Disclosures: Perkins: MMRC: Employment. Reeder:Celgene: Research Funding; Millennium: Research Funding. Fonseca:Otsuka: Consultancy; BMS: Consultancy; Amgen: Consultancy; Medtronic: Consultancy; Genzyme: Consultancy.

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Induction Of Proliferation and Survival Of Multiple Myeloma Cells By CD137 Ligand Reverse Signaling

Blood ◽

10.1182/blood.v122.21.2537.2537 ◽

2013 ◽

Vol 122 (21) ◽

pp. 2537-2537

Author(s):

Chengcheng Fu ◽

Hui Liu ◽

Juan Wang ◽

Ling Ma ◽

Songguang Ju ◽

...

Keyword(s):

Multiple Myeloma ◽

Flow Cytometry ◽

Cell Proliferation ◽

Cell Surface ◽

B Cell ◽

Cell Lines ◽

Plasma Cells ◽

Cell Counting ◽

Myeloma Cells ◽

Reverse Signaling

Abstract CD137 and its ligand are members of the Tumor Necrosis Factor (TNF) receptor and TNF superfamilies, respectively, regulate cell activation and proliferation of immune system. CD137L, in addition to its ability to costimulate T cells by triggering CD137 receptor, also signals back into antigen presenting cells inducing proliferation, prolonging survival and enhancing secretion of proinflammatory cytokines. The expression of CD137L and its function on multiple myeloma cells is unknown. We identified the constitutive expression of CD137L by flow cytometry on U266, RPMI 8226, LP1, MY5 and KMS-11 of Multiple myeloma (MM) cell lines as high as 96%, 97.5%, 89%, 93% and 94%.But, CD137 expressed on the cell surface was low as 4%, 5%, 1%, 2%, 5% respectively. Now that, CD137L was expressed very strongly on MM cell lines, next, we investigated CD137L expression of MM cells from 85 BM samples of patients seen in the hematological Dept of the First Affiliated Hosp. of Soochow University between January 2012 and June 2013 and diagnosed of active multiple MM, including the patients of newly-diagnosed (n=35), relapsed (n=5) and after 2- 4 prior therapies (n=45). The BM samples were examined using antibodies against CD45RO PE-Cy7, CD138 APC-H7, CD38 FITC and CD137L PE, according to standard protocols for surface staining. Indeed, CD137L protein was expressed by a select group of CD45-CD38++CD138+cells as higher than 95%, the same, CD38 and CD138 are expressed more than 90% of the cells of CD45-CD137L+.There were 22 samples from 11 cases collected before and after treatment and this was further evidence that CD137L molecule was consistently expressed on the MM cell surface. However, CD137L expression was not or hardly detectable on normal plasma cells confirmed by CD45+CD38++CD138+ CD56- CD19+, indicating that CD137L was ectopically expressed by MM cells and probably a specific marker of MM cells. The ectopic CD137L expression was not a mere epiphenomenon but was selected for, what function of it? We hypothesized that it would also act as a growth stimulus for B cell cancers. Then we selected U266-a MM cell line to explore the biological effect of CD137L reverse signaling and its underlying mechanism. As a result, in vitro study, U266 cells(2X105/ml))were cultured plate pre-coated with mAb 1F1 or irrelevant mouse IgG at l ug/ml in PBS and at 400 ul per well of 24-well plate or 80 ul per well of 96-well plate and washed twice after overnight incubation at 4°C. The proliferation and survival of U266 was enhanced by stimulating- CD137L mAb (1F1) than those induced by control mouse IgG by cell counting (4.2 X105/ml VS 3.3 X105/ml), WST-8(1.15 VS 0.81) and CFSE assay (930 VS 991) at incubation for 48h. In addition, the cell cycle analysis showed that CD137L induces proliferation and increases the number of cells in the S phase from 36.1% to 42.5% after 72h incubation. The percentage of apoptosis cells (Annexin V+ and PI+) was 19.6% VS 21.2% with no statistical significance. In order to explore the mechanism of the function of CD137L on MM cells, we surveyed the cytokine profiles during the incubation of U266 cells cultured for 2 days with different stimuli with mAb 1F1 compared with the control group. Intracellular cytokine staining showed that treatment of cells with 1F1 increased the production of IL-6 from 3.8% to 63.9% by Flow cytometry. When neutralizing anti-IL-6 mAb (5 ug/ml) was added to the culture medium, the cells(2X105/ml))were cultured for 48 h in pure medium or plus 10 ng/ml Fc or CD137–Fc protein and the cell proliferation measured by WST-8 was 0.79 VS 0.80 VS 0.72.1F1-induced cell proliferation was effectively inhibited. IL-6 can promote cell proliferation and survival of MM. An increase of these cytokines might explain why CD137L expression could stimulate the proliferation of U266. Finally, the U266 cells were treated with bortezomib and the growth of cells was analyzed by WST-8 assay. It demonstrated that bortezomib could inhibit the function of 1F1 and the inhibition ratio of bortezomib was 22%, 51% and 58% at 24h, 48h and 72h. MM is a B-cell malignancy characterized by the clonal expansion and accumulation of malignant plasma cells in the bone marrow. In our study, CD137L is not only a novel ectopic constitutive marker of MM, but also a promoting proliferation factor. This suggests the possibility that its expression on MM cells may be directly target for immunomodulatory therapy for MM. Disclosures: No relevant conflicts of interest to declare.

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Targeting EZH2 in Multiple Myeloma Could be Promising for a Subgroup of MM Patients in Combination with IMiDs

Blood ◽

10.1182/blood.v128.22.311.311 ◽

2016 ◽

Vol 128 (22) ◽

pp. 311-311 ◽

Cited By ~ 4

Author(s):

Laurie Herviou ◽

Alboukadel Kassambara ◽

Stephanie Boireau ◽

Nicolas Robert ◽

Guilhem Requirand ◽

...

Keyword(s):

Multiple Myeloma ◽

Bone Marrow ◽

Board Of Directors ◽

Research Funding ◽

Plasma Cells ◽

Newly Diagnosed ◽

Advisory Committees ◽

Myeloma Cells ◽

Ezh2 Expression ◽

Bone Marrow Plasma

Abstract Multiple Myeloma is a B cell neoplasia characterized by the accumulation of clonal plasma cells within the bone marrow.Epigenetics is characterized by a wide range of changes that are reversible and orchestrate gene expression. Recent studies have shown that epigenetic modifications play a role in multiple myeloma (MM) by silencing various cancer-related genes. We investigated the epigenetic genes differentially expressed between normal bone marrow plasma cells (BMPC ; N=5) and MM plasma cells from patients (N=206). Using SAM (Significance Analysis of Microarrays) analysis, only 12 genes significantly differentially expressed between BMPC and MM cells (ratio > 2 and FDR (false discovery rate) < 5%) were identified, including the EZH2 histone methyltransferase. EZH2, the enzymatic subunit of Polycomb Repressive Complex 2, is a histone methyltransferases able to repress gene expression by catalyzing H3K27me3 histone mark. EZH2 overexpression has been associated with numerous hematological malignancies, including MM. We thus studied EZH2 role in MM physiopathology and drug resistance. EZH2 expression was analyzed in normal bone marrow plasma cells (BMPCs; N=5), primary myeloma cells from newly diagnosed patients (MMCs; N=206) and human myeloma cell lines (HMCLs; N=40) using Affymetrix microarrays. EZH2 gene is significantly overexpressed in MMCs of patients (median 574, range 105 - 4562) compared to normal BMPCs (median = 432; range: 314 - 563) (P < 0.01). The expression is even higher in HMCLs (median 4481, range 581 - 8455) compared to primary MMCs or BMPCs (P < 0.001). High EZH2 expression is associated with a poor prognosis in 3 independent cohorts of newly diagnosed patients (Heidelberg-Montpellier cohort - N=206, UAMS-TT2 cohort - N=345 and UAMS-TT3 cohort - N =158). Furthermore, GSEA analysis of patients with high EZH2 expression highlighted a significant enrichment of genes involved in cell cycle, downregulated in mature plasma cells vs plasmablasts, and EZH2 targets. Specific EZH2 inhibition by EPZ-6438 EZH2 inhibitor induced a significant decrease of global H3K27me3 in all the HMCLs tested (P < 0.01) and inhibited MM cell growth in 5 out of the 6 HMCLs tested. The inhibitory effect of EZH2 inhibitor on MM cell growth appeared at day 6 suggesting that it is mediated by epigenetic reprogramming. To confirm that EZH2 is also required for the survival of primary MMCs from patients, primary MM cells (n = 17 patients) co-cultured with their bone marrow microenvironment and recombinant IL-6 were treated with EPZ-6438. As identified in HMCLs, EZH2 inhibition significantly reduced the median number of viable myeloma cells by 35% (P = 0.004) from a subset of patients (n=9) while the other group (n=8) was resistant. Of interest, EPZ-6438 induced a significant global H3K27me3 decrease in both groups of patient. RNA sequencing of 6 HMCLs treated with EPZ-6438 combined with H3K27me3 ChIP analyses allowed us to create an EZ GEP-based score able to predict HMCLs and primary MM cells sensitivity to EZH2 inhibitors. We also observed a synergy between EPZ-6438 and Lenalidomide, a conventional drug used for MM treatment. More interestingly, pretreatment of myeloma cells with EPZ-6438 significantly re-sensitize drug-resistant MM cells to Lenalidomide. Investigating the effect of EPZ-6438/Lenalidomide combination in MMC, we identified that IKZF1, IRF4 and MYC protein levels were significantly more inhibited by the combination treatment (65.5%, 63.9% and 14.8% respectively) compared with Lenalidomide (51.5%, 43% and 2.2%) or EPZ-6438 (45.2%, 38.7% and 6.2%) alone. Clinical trials are ongoing with EZH2 inhibitors in lymphoma and could be promising for a subgroup of MM patients in combination with IMiDs. Furthermore, the EZ score enables identification of MM patients with an adverse prognosis and who could benefit from treatment with EZH2 inhibitors. Disclosures Goldschmidt: Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Onyx: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Membership on an entity's Board of Directors or advisory committees, Research Funding; Millennium: Membership on an entity's Board of Directors or advisory committees, Research Funding; Chugai: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees. Hose:EngMab: Research Funding; Takeda: Other: Travel grant; Sanofi: Research Funding.

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SDX-308, a nonsteroidal anti-inflammatory agent, inhibits NF-κB activity, resulting in strong inhibition of osteoclast formation/activity and multiple myeloma cell growth

Blood ◽

10.1182/blood-2006-07-027458 ◽

2006 ◽

Vol 109 (5) ◽

pp. 2130-2138 ◽

Cited By ~ 34

Author(s):

Rentian Feng ◽

Gülsüm Anderson ◽

Guozhi Xiao ◽

Gary Elliott ◽

Lorenzo Leoni ◽

...

Keyword(s):

Multiple Myeloma ◽

Cell Proliferation ◽

Bone Resorption ◽

Bone Destruction ◽

Structural Analog ◽

Myeloma Cell ◽

Osteoclast Formation ◽

Myeloma Cells ◽

Osteoclast Activity ◽

Multiple Myeloma Cell

Abstract Multiple myeloma is characterized by increased osteoclast activity that results in bone destruction and lytic lesions. With the prolonged overall patient survival achieved by new treatment modalities, additional drugs are required to inhibit bone destruction. We focused on a novel and more potent structural analog of the nonsteroidal anti-inflammatory drug etodolac, known as SDX-308, and its effects on osteoclastogenesis and multiple myeloma cells. SDX-101 is another structural analog of etodolac that is already used in clinical trials for the treatment of B-cell chronic lymphocytic leukemia (B-CLL). Compared with SDX-101, a 10-fold lower concentration of SDX-308 induced potent (60%-80%) inhibition of osteoclast formation, and a 10- to 100-fold lower concentration inhibited multiple myeloma cell proliferation. Bone resorption was completely inhibited by SDX-308, as determined in dentin-based bone resorption assays. SDX-308 decreased constitutive and RANKL-stimulated NF-κB activation and osteoclast formation in an osteoclast cellular model, RAW 264.7. SDX-308 effectively suppressed TNF-α–induced IKK-γ and IκB-α phosphorylation and degradation and subsequent NF-κB activation in human multiple myeloma cells. These results indicate that SDX-308 effectively inhibits multiple myeloma cell proliferation and osteoclast activity, potentially by controlling NF-κB activation signaling. We propose that SDX-308 is a promising therapeutic candidate to inhibit multiple myeloma growth and osteoclast activity and that it should receive attention for further study.

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Circulating Multiple Myeloma Cells (CMMCs): A Novel Method for Detection and Molecular Characterization of Peripheral Blood Plasma Cells in Multiple Myeloma Precursor States

Blood ◽

10.1182/blood.v124.21.2031.2031 ◽

2014 ◽

Vol 124 (21) ◽

pp. 2031-2031

Author(s):

Brendan Weiss ◽

Kate Sasser ◽

Chandra Rao ◽

Brad Foulk ◽

Steven Gross ◽

...

Keyword(s):

Multiple Myeloma ◽

Molecular Characterization ◽

Research Funding ◽

Plasma Cells ◽

Employment Equity ◽

Myeloma Cells ◽

Novel Method ◽

Equity Ownership ◽

Precursor States

Abstract Background Circulating plasma cells (PCs) have been identified as a prognostic factor in patients with myeloma precursor states (MGUS and SMM) and active multiple myeloma (MM). Enumeration of circulating PCs by available methods is not suitable for widespread use and does not provide molecular characterization. We developed and evaluated a novel method for enumeration and molecular characterization of circulating PCs (circulating multiple myeloma cells, “CMMC”), based on the CELLSEARCH® System (Janssen Diagnostics LLC, Raritan, NJ), an automated technology for the capture, enumeration and characterization of rare cells in the peripheral blood. Methods We are performing a prospective study of patients with MGUS and SMM to evaluate CMMCs as biomarker for progression to active MM. Utilizing the CELLSEARCH® System CMMCs were captured by CD138 ferrofluid magnetic particles and identification was defined as CD38+ and CD19-, CD45-. Nonviable cells were excluded by DAPI. Isolated CMMCs were stored and FISH for t(4:14), t(14;16) and del17 was performed. Results We have enrolled 16 patients, MGUS = 3, SMM = 11, and newly diagnosed MM = 2. The Mayo Risk stratification for MGUS patients was: low risk = 2, low-intermediate = 1. All SMM patients were low risk by Mayo Model incorporating serum free light chains. The median number of bone marrow plasma cells for MGUS patients was 7 (range 7-9) and for SMM patients was 15 (range 10-40). The median CMMCs for MGUS = 6 (range 2-55), median CMMCs for SMM = 31 (5-1918). The two patients with NDMM had 5870 and 5 CMMCs, respectively. A single patient with SMM progressed with a symptomatic solitary lumbar plasmacytoma and had CMMCs of 5 and 3 at baseline and progression, respectively. Abnormalities by FISH were detected in both bone marrow and CMMCs. Accrual is ongoing and additional data will be presented at the meeting. Conclusions The CELLSEARCH® CMMC assay can detect, quantify and provide molecular characterization of circulating PCs in MGUS/SMM/MM; longer prospective follow-up is needed to test the prognostic value of CMMCs. Disclosures Weiss: Janssen: Consultancy, Research Funding. Sasser:Janssen: Employment. Rao:Janssen: Employment, Equity Ownership. Foulk:Janssen: Employment. Gross:Johnson & Johnson: Employment, Equity Ownership. Cohen:Janssen: Membership on an entity's Board of Directors or advisory committees. Vogl:Celgene Corporation: Consultancy; Amgen: Consultancy; Millennium/Takeda: Research Funding; GSK: Research Funding; Acetylon: Research Funding. Stadtmauer:Janssen: Consultancy.

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