Preferential Inhibition of Malignant Cell Growth by CDDO in Waldenström Macroglobulinemia.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2528-2528
Author(s):  
Sherine F. Elsawa ◽  
Anne J. Novak ◽  
Marina Konopleva ◽  
Michael Andreeff ◽  
Thomas E. Witzig ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Cell Proliferation ◽  
Cell Death ◽  
B Cells ◽  
Cell Growth ◽  
Peripheral Blood ◽  
Malignant Cell ◽  
Dependent Manner ◽  
Malignant Cells ◽  
Dose Dependent

Waldenström macroglobulinemia (WM) is a B cell disorder with a highly variable clinical outcome, where some patients remain asymptomatic, while others have significant symptoms and require therapeutic intervention. Clinical symptoms include infiltration of lymphoplasmacytic cells into the bone marrow, production of a monoclonal IgM protein, anemia, lymphadenopathy, and serum hyperviscosity. Despite the introduction of multiple chemotherapeutic regimens over the past several decades, WM remains an incurable disease. 2-cyano-3,12-dioxoolean-1,9-dien-28-oic acid (CDDO) and its methyl ester derivative (CDDO-Me) and imidazolide derivative (CDDO-Im) are synthetic triterpenoids derived from oleanolic acid. These compounds have been shown to induce apoptosis of several tumor cell types including breast cancer, lung cancer, ovarian cancer, melanoma, osteosarcoma, leukemia, and multiple myeloma cells. The goal of this study was to evaluate the potential role of synthetic triterpenoids in WM. Preliminary studies on malignant B cells indicated that CDDO-Im induced the greatest amount of cell death and we therefore used this derivative of CDDO for our studies. CD19+ CD138+ cells from bone marrow biopsy specimens obtained from WM patients were isolated by positive selection and were treated with varying concentrations of CDDO-Im (62.5 nM to 750 nM ) and cell viability was determined after 24 hours (n=3). Compared to the nil control 47% of the malignant cells remained viable at a CDDO-Im concentration of 62.5 nM and only 11% remained viable at 125 nM CDDO-Im. To determine if CDDO-Im had specific toxic effects on non-malignant cells, we cultured CD19- CD138- cells from WM patient bone marrows with CDDO-Im and found that non-malignant cells were less sensitive to the drug, 80% being viable at 62.5 nM and 65% being viable at 125 nM. Similarly, we found that normal peripheral blood B cells and CD19+ CD138+ bone marrow B cells from healthy donors were less sensitive to CDDO-Im. Compared to the nil control 93% of the CD19+ CD138+ bone marrow B cells and 70% of the peripheral blood B cells remained viable at a CDDO-Im concentration of 62.5 nM and 95% and 68% remained viable at 125 nM CDDO-Im respectively. We next examined the effect of CDDO-Im on WM cell proliferation and found that CDDO-Im inhibited cell proliferation in a dose-dependent manner. Similar to the viability assays, there was a differential effect of CDDO-Im on malignant and non-malignant cells. Compared to the nil control, at 125 nM, there was a complete inhibition of malignant cell growth, while approximately 40% of the non-malignant cells remained proliferative. To determine the mechanism of cell death, CD19+ CD138+ cells were cultured in the presence or absence of various doses of CDDO-Im for 6 hours and cell lysates were examined for cleavage of PARP. There was evidence of PARP cleavage in a dose-dependent manner, suggesting that CDDO-Im induced malignant cell death occurs through a caspase-dependent mechanism. In summary, the synthetic triterpenoid CDDO-Im decreased the viability of WM B cells in a dose-dependent manner, and CDDO-Im had a greater effect on the viability of the malignant cells compared to non-malignant cells from the same WM patients. CDDO-Im also inhibited malignant cell growth in a dose-dependent manner and the mechanism of CDDO-Im mediated cell death appears to be a caspase-mediated event. Overall, our data indicate that CDDO-Im may have potential efficacy in WM patients.

scholarly journals Activated CD4+CD25+ T cells selectively kill B lymphocytes

Blood ◽  
2006 ◽  
Vol 107 (10) ◽  
pp. 3925-3932 ◽  
Author(s):  
Dong-Mei Zhao ◽  
Angela M. Thornton ◽  
Richard J. DiPaolo ◽  
Ethan M. Shevach
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
Cell Death ◽  
B Cells ◽  
B Cell ◽  
T Cell Activation ◽  
Fas Ligand ◽  
Cell Function ◽  
Cell Contact ◽  
Dependent Manner

The suppressive capacity of naturally occurring mouse CD4+CD25+ T cells on T-cell activation has been well documented. The present study is focused on the interaction of CD4+CD25+ T cells and B cells. By coculturing preactivated CD4+CD25+ T cells with B cells in the presence of polyclonal B-cell activators, we found that B-cell proliferation was significantly suppressed. The suppression of B-cell proliferation was due to increased cell death caused by the CD4+CD25+ T cells in a cell-contact–dependent manner. The induction of B-cell death is not mediated by Fas–Fas ligand pathway, but surprisingly, depends on the up-regulation of perforin and granzymes in the CD4+CD25+ T cells. Furthermore, activated CD4+CD25+ T cells preferentially killed antigen-presenting but not bystander B cells. Our results demonstrate that CD4+CD25+ T cells can act directly on B cells and suggest that the prevention of autoimmunity by CD4+CD25+ T cells can be explained, at least in part, by the direct regulation of B-cell function.

KRN5500, a Spicamycin Derivative, Exerts Anti-Myeloma Effects through Impairing Both Myeloma Cells and Osteoclasts.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1669-1669
Author(s):  
Hirokazu Miki ◽  
Shuji Ozaki ◽  
Osamu Tanaka ◽  
Shingen Nakamura ◽  
Ayako Nakano ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Drug Resistance ◽  
Cell Death ◽  
Cell Growth ◽  
Cell Lines ◽  
G1 Arrest ◽  
Dependent Manner ◽  
Osteolytic Bone Disease ◽  
Rpmi 8226

Abstract Multiple myeloma (MM) is a plasma cell malignancy characterized by devastating bone destruction due to enhanced bone resorption and suppressed bone formation. Although high-dose chemotherapy and new agents such as thalidomide, lenalidomide, and bortezomib have shown marked anti-MM activity in clinical settings, MM remains incurable due to drug resistance mediated by interactions with osteoclasts or stroma cells. Moreover, osteolytic bone disease continues to be a major problem for many patients. Therefore, alternative approaches are necessary to overcome drug resistance and inhibit osteoclasts activity in MM. KRN5500 is a new derivative of spicamycin produced by Streptomyces alanosinicus (Kirin Pharma, Tokyo, Japan), which potently inhibits protein synthesis and induces cell death in human tumor cell lines. Phase I studies of KRN5500 in patients with solid tumors such as colon cancer and gastric cancer showed acceptable toxicity with Cmax values of 1000––3000 nM. In this study, we investigated the effects of KRN5500 against MM cells and osteoclasts in vitro and in vivo. MM cell lines such as RPMI 8226, MM.1S, INA-6, KMS12-BM, UTMC-2, TSPC-1, and OPC were incubated with various concentrations of KRN5500 for 3 days. Cell proliferation assay showed marked inhibition of cell growth with G1 arrest in these MM cells (IC50: 4–100 nM). KRN5500 (100 nM) also induced 30–90% of cell death in primary MM cells (n=7). Annexin V/propidium iodide staining showed that KRN5500 induced apoptosis of MM cells in a dose- and time-dependent manner. Western blot analysis confirmed activation of caspase-8, -9, and −3, cleavage of poly (ADP-ribose) polymerase (PARP), and down-regulation of Mcl-1. We next examined the effect of KRN5500 against MM cell lines and primary MM cells in the presence of bone marrow stroma cells and osteoclasts. Co-culture of these cells enhanced viability of MM cells; however, KRN5500 still induced strong cytotoxicity to MM cells. Of interest, KRN5500 specifically mediated apoptosis in osteoclasts but not stroma cells as assessed by TUNEL staining. More than 90% of osteoclasts were killed even at a low concentration of KRN5500 (20 nM). Finally, we evaluated the effect of KRN5500 against MM cells and osteoclasts in vivo. Two xenograft models were established in SCID mice by either subcutaneous injection of RPMI 8226 cells or intra-bone injection of INA-6 cells into subcutaneously implanted rabbit bones (SCID-rab model). These mice were treated with intraperitoneal injection of KRN5500 (5 mg/kg/dose) or saline thrice a week for 3 weeks after tumor development. In a subcutaneous tumor model, KRN5500 inhibited the tumor growth compared with control mice (increased tumor size, 232 ± 54% vs 950 ± 422%, p<0.001, n=6 per group). In a SCID-rab model, KRN5500 also inhibited MM cell growth in the bone marrow (increase of serum human sIL6-R derived from INA-6, 134 ± 19% vs 1112 ± 101%, p<0.001, n=5 per group). Notably, the destruction of the rabbit bones was also prevented in the KRN5500-treated mice as evaluated by radiography. Therefore, these results suggest that KRN5500 exerts anti-MM effects through impairing both MM cells and osteoclasts and that this unique mechanism of action provides a valuable therapeutic option to improve the prognosis in patients with MM.

Monocytes Modulate Megakaryocyte-Mediated Fibrosis of Bone Marrow Stromal Cells in Vitro

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1759-1759
Author(s):  
Emil Tom Kuriakose ◽  
Jason Shieh ◽  
Jae Hung Shieh ◽  
Richard T. Silver ◽  
Malcolm A.S. Moore
Keyword(s):  
Bone Marrow ◽  
Tissue Culture ◽  
Positive Selection ◽  
Peripheral Blood ◽  
Normal Adult ◽  
Dependent Manner ◽  
Marrow Stroma ◽  
Dose Dependent ◽  
Selection Of

Abstract Abstract 1759 Myelofibrosis (MF) is a terminal feature of the chronic myeloproliferative neoplasms (MPNs), primary myelofibrosis (PMF), polycythemia vera (PV) and essential thrombocythemia (ET).We and others have shown, using both in vitro and in vivo models, that proliferation of megakaryocytes (MK) and their pathologic interaction with marrow stroma plays a central role in MF. However, the marrows of patients with MPNs remain free of fibrosis for a substantial part of their clinical course, despite increased MK proliferation and turnover in the marrow, suggesting that additional factors may modulate the fibrotic effects of the MK on marrow stroma. Since monocytosis is often seen in patients with MF, we examined whether monocytes may play such a role in MF. Human hematopoietic stem cells (HSC), MK progenitors, and circulating monocytes were obtained from peripheral blood of 13 patients with MF (3 post PV MF, 10 PMF), G-CSF mobilized peripheral blood from normal adults (MPB), and cord blood (CB) using MACS column separation by positive selection of cells expressing CD34, CD41, and CD14 respectively. HSCs were cultured in serum free medium (SFM) on the murine bone marrow stromal cell line OP9 transduced with an adenoviral vector expressing the human thrombopoietin gene (OP9-adenoTPO). After 10–12 days in culture, mature MKs were harvested using MACS column by positive selection of cells expressing human CD41. Purity of cell fractions was more than 90% by flow cytometry. Isolated MKs and monocytes were seeded with trypsinized OP9 in SFM at various ratios on 96 well or 384 well tissue culture treated plates and incubated at 37° C. MKs formed focal aggregates on adherent OP9 cells within 24 hours, which by 48 hours, became round dark fibrotic nodules when seen using phase contrast microscopy. Formation of these focal fibrosis (FF) areas was more pronounced with higher MK:OP9 ratios, and was equally induced by MKs from MF patients, normal adult MKs, and CB MKs. FF was not observed with CD41 negative cells, nor in control OP9 wells. Time lapse photography revealed that FF formation involved migration of both MKs and OP9 cells, and that FF was enhanced by inhibition of CXCR4 using AMD3100. Peripheral blood monocytes from normal adult controls and CB did not induce formation of FF. Circulating monocytes from most MF patients induced FF, but to a lesser degree than MKs. Addition of monocytes to MK-OP9 FF showed that normal adult monoctyes inhibited FF formation in a dose dependent manner, whereas monocytes of MF patients had variable effects, with some inhibiting FF, and others not. To determine whether differential conditioning of monocytes can induce variable stromal changes, normal adult circulating monocytes were cultured in SFM with TGF- ß1, interferon alfa (IFNα), and TNFα in tissue culture flasks. Monocytes cultured in TNFα (MoTNF) became adherent and spindle shaped within 72 hours. Conditioned medium (CM) from MoTNF suppressed OP9 differentiation into adipocytes in a dose dependent manner. CM from monocytes cultured in IFNα (MoIFN) enhanced OP9 differentiation into adipocytes in a dose dependent manner. MoTGF caused proliferation of OP9 and suppressed adipocyte differentiation, but was not significantly different from control with TGFβ alone. CM from MoIFN decreased FF formation by MKs on OP9 and increased adipocyte number, but IFNα by itself had no such effect on FF formation. Both CM from MoTNF and TNFα increased FF formation by MKs in a dose dependent manner. Together, these results demonstrate that monocytes can enhance or hinder MK induced fibrosis depending on their conditioning by specific cytokines, with IFNα hindering and TNFα enhancing the fibrotic effect. Our data suggest that the known anti-megakaryocytic and anti-fibrotic activities of IFNα may be due to its conditioning of monocytes into an anti-fibrotic phenotype. Disclosures: No relevant conflicts of interest to declare.

Inhibition Of PI3K Classia Kinases Using GDC0941 Overcomes Protection Of Multiple Myeloma Cells In The Bone Marrow Microenvironment

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3169-3169
Author(s):  
Hugh Kikuchi ◽  
Amofa Eunice ◽  
Maeve McEnery ◽  
Farzin Farzaneh ◽  
Stephen A Schey ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Bone Marrow ◽  
Cell Proliferation ◽  
Bone Resorption ◽  
Cell Lines ◽  
Stromal Cells ◽  
Conflicts Of Interest ◽  
Pi3k Pathway ◽  
Dependent Manner ◽  
Dose Dependent

Abstract Despite of newly developed and more efficacious therapies, multiple myeloma (MM) remains incurable as most patient will eventually relapse and become refractory. The bone marrow (BM) microenvironment provides niches that are advantageous for drug resistance. Effective therapies against MM should ideally target the various protective BM niches that promote MM cell survival and relapse. In addition to stromal mesenchymal/myofibroblastic cells, osteoclasts play a key supportive role in MM cell viability. Additionally, 80% of patients develop osteolytic lesions, which is a major cause of morbidity. Increased osteoclast activity is characteristic in these patients and targeting osteoclast function is desirable to improve therapies against MM. Osteoclasts need to form an F-actin containing ring along the cell margin that defines a resorbing compartment where protons and degradative enzymes are secreted for dissolution of bone mineral. Remodelling of F-actin and vesicle secretion are regulated by the class IA PI3K pathway during osteoclastic bone resorption. Additionally, it has recently been shown that inhibition of the class IA PI3K pathway in MM cells with GDC0941 induces apoptosis-mediated killing. We hypothesised that GDC0941 could be used as a therapeutic agent to overcome MM-induced osteoclast activation. GDC0941 inhibited maturation of osteoclasts derived from BM aspirates from MM patients in a dose dependent manner. This correlated with decreased bone resorption of osteoclasts cultured on dentine discs. Exposure of mature osteoclasts to GC0941 resulted in abnormal organisation of larger F-actin rings, suggesting a negative effect on the dynamics of the actin cytoskeleton required for bone resorption. We also found that GDC-0941 can prevent protection of the MM cell lines MM1.S and MM1.R by osteoclasts against killing. GDC-0941 alone blocked MM cell proliferation independently of the presence of BM stromal cells and synergised with other therapeutic agents including Lenalidomide, Pomalidomide, Bortezomid and Dexamethasone. We also found that in the presence of MM cells, Dexamethasone (a drug commonly used alone or in combination with new drugs against MM) induced the proliferation of BM stromal cells and adhesion of MM cells on this protective stroma in a dose dependent manner. Dexamethasone is highly effective at MM cell killing when cells are cultured alone. However, we found that at low doses (below 1 uM) and in the presence of BM stromal cells, Dexamethasone could induce MM cell proliferation. GDC0941 enhanced Dexamethasone killing even in the presence of BM stromal cells by blocking Dexamethasone-induced stromal cell proliferation and adhesion of MM cells on the stroma. Targeting individual the PI3K Class IA isoforms alpha, beta, delta or gamma proved to be a less efficient strategy to enhance Dexamethasone killing. Previous work has shown that efficacy of targeting individual PI3K Class I A isoforms would be low for activation of caspases in MM cells as it would be dependent on relative amounts of isoforms expressed by the MM patient. GDC-0941 also inhibited the proliferation of MM1.R and RPMI8266 MM cell lines, which are less sensitive to treatment to Dexamethasone. Co-culture of MM cells with BM stromal cells induced the secretion of IL-10, IL-6, IL-8, MCP-1 and MIP1-alpha. The dose-dependant increased proliferation of Dexamethasone-treated MM cells in the presence of the BM stroma correlated with the pattern of secretion of IL-10 (a cytokine that can induce B-cell proliferation) and this was blocked by the combination of Dexamethasone with GDC0941. GDC-0941 alone or in combination with Dexamethasone was more efficacious at inducing MM cell apoptosis in the presence of the BM stroma cells vs treatment of MM cells alone. These are very encouraging results as they suggest that GDC-0941 in combination with Dexamethasone would be potentially highly efficacious for targeting MM cells in the BM microenvironment. We are currently performing in vivo data using C57BL/KaLwRij mice injected with 5T33-eGFP MM cells that will be discussed at the meeting. We propose that MM patients with active bony disease may benefit from treatment with GDC0941 alone or in combination with currently used therapeutic drugs against MM. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Thiols decrease human interleukin (IL) 4 production and IL-4-induced immunoglobulin synthesis.

1995 ◽  
Vol 182 (6) ◽  
pp. 1785-1792 ◽  
Author(s):  
P Jeannin ◽  
Y Delneste ◽  
S Lecoanet-Henchoz ◽  
J F Gauchat ◽  
P Life ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Peripheral Blood ◽  
Messenger Rna ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Dependent Manner ◽  
Dose Dependent

N-Acetyl-L-cysteine (NAC) is an antioxidant precursor of intracellular glutathione (GSH), usually given in human as a mucolytic agent. In vitro, NAC and GSH have been shown to act on T cells by increasing interleukin (IL) 2 production, synthesis and turnover of IL-2 receptors, proliferation, cytotoxic properties, and resistance to apoptosis. We report here that NAC and GSH decrease in a dose-dependent manner human IL-4 production by stimulated peripheral blood T cells and by T helper (Th) 0- and Th2-like T cell clones. This effect was associated with a decrease in IL-4 messenger RNA transcription. In contrast, NAC and GSH had no effect on interferon gamma and increased IL-2 production and T cell proliferation. A functional consequence was the capacity of NAC and GSH to selectively decrease in a dose-dependent manner IL-4-induced immunoglobulin (Ig) E and IgG4 production by human peripheral blood mononuclear cells. Interestingly, NAC and GSH also acted directly on purified tonsillar B cells by decreasing the mature epsilon messenger RNA, hence decreasing IgE production. In contrast, IgA and IgM production were not affected. At the same time, B cell proliferation was increased in a dose-dependent manner. Not all antioxidants tested but only SH-bearing molecules mimicked these properties. Finally, when given orally to mice, NAC decreased both IgE and IgG1 antibody responses to ovalbumin. These results demonstrate that NAC, GSH, and other thiols may control the production of both the Th2-derived cytokine IL-4 and IL-4-induced Ig in vitro and in vivo.

Inhibition of Human Plasmacytoma Cell Growth by a Novel JAK Kinase Inhibitor.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 644-644
Author(s):  
Renate Burger ◽  
Steven Legouill ◽  
Yu-Tzu Tai ◽  
Reshma Shringarpure ◽  
Klaus Podar ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Cell Growth ◽  
Cell Lines ◽  
Hormone Receptors ◽  
Critical Role ◽  
Myeloma Cell ◽  
Thymidine Uptake ◽  
Dependent Manner ◽  
Jak Kinase ◽  
Dose Dependent

Abstract Novel strategies in cancer therapy aim at inhibiting distinct signal transduction pathways that are aberrantly activated in malignant cells. Protein tyrosine kinases of the JAK family are associated with a number of cytokine and cytokine-like hormone receptors and regulate important cellular functions such as proliferation, survival, and differentiation. Constitutive or enhanced JAK activation has been implicated in neoplastic transformation and abnormal cell proliferation in various hematological malignancies. In multiple myeloma (MM), JAK kinases play a critical role because of their association with cytokine receptors of the IL-6/gp130 family. A novel small-molecule inhibitor was developed that shows a 100 to 1,000-fold selectivity for JAK1, JAK2, JAK3, and TYK2 relative to other kinases including Abl, Aurora, c-Raf, FGFR3, GSK3b, IGF-1R, Lck, PDGFRa, PKBb, and Zap-70. Growth of MM cell lines and primary patient cells was inhibited by this compound in a dose-dependent manner. The IL-6 dependent cell line INA-6 and derived sublines were sensitive to the drug, with IC50’s of less than 1 mM, in [3H]-thymidine uptake and a colorimetric, tetrazolium compound (MTS) based assay (CellTiter 96® Aqueous One Solution Cell Proliferation Assay, Promega, Madison, WI). Importantly, INA-6 and patient tumor cell growth was also inhibited in the presence of bone marrow stromal cells, which by themselves remained largely unaffected. Growth suppression of INA-6 correlated with a significant and dose-dependent increase in the percentage of apoptotic cells, as evaluated by Apo2.7 staining after 48 hours of drug treatment. In addition, the compound blocked IL-6 induced phosphorylation of STAT3, a direct downstream target of JAK kinases and important transcription factor triggering anti-apoptotic pathways. In other myeloma cell lines, the drug overcame the protective effect of gp130 cytokines on dexamethasone induced apoptosis. In MM1.S cells, it completely blocked IL-6 induced phosphorylation of SHP-2 and AKT, both known to mediate the protective effects of IL-6. In contrast, AKT phosphorylation induced by IGF-1 remained unchanged, demonstrating selectivity of the compound. These studies show that disruption of JAK kinase activity and downstream signaling pathways inhibits myeloma cell growth and survival as well as circumvents drug resistance, thereby providing the conceptual basis for the use of JAK kinase inhibitors as a novel therapeutic approach in MM.

Interference Of The Tumor Supportive Effects Of BCL2 and MCL1 Sensitize Malignant Plasma Cells To The Lethal Effects Of Lenalidomide and Dexamethasone Regimen: An Important Clinical Path For BCL2 Targeting Drugs

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 1928-1928
Author(s):  
Aneel Paulus ◽  
Kasyapa S. Chitta ◽  
Sharoon Akhtar ◽  
Maja Kuranz ◽  
Shaji Kumar ◽  
...  
Keyword(s):  
Gene Expression ◽  
Bone Marrow ◽  
Cell Death ◽  
Plasma Cell ◽  
Plasma Cells ◽  
Myeloma Cell ◽  
Dependent Manner ◽  
Mrna Quantification ◽  
Bcl2 Family ◽  
Dose Dependent

Abstract Background Multiple myeloma (MM) is the second most common hematologic malignancy in the U.S. and is characterized by increased immunoglobulin production and infiltration of the bone marrow by malignant plasma cells. Myeloma cell growth is supported by both the elements present in the bone marrow microenvironment as well as deregulation of internal cellular systems associated with proliferation and apoptosis. Defective programmed cell death by BCL2 or MCL1 upregulation is observed in >80% of myeloma cases and is associated with an aggressive clinical course. Remarkably, there is no approved drug with the ability to target BCL2 or MCL1. Various strategies to mitigate the effects of increased BCL2 functionality, via small molecule inhibitors or BCL2-specific antisense oligonucleotides have been previously examined in MM. These studies revealed that 1) apart from BCL2, additional anti-apoptotic members belonging to the BCL2 family (i.e. MCL1, BCL-xL) play integral roles in maintenance of the myeloma cell phenotype, 2) drugs, which target only BCL2 offer limited therapeutic advantage and 3) given that survival factors engaged in MM are multifactorial, perhaps isolated targeting of the BCL2 pathways may not be sufficient. We therefore hypothesized that the clinical development of drugs that target various antiapoptotic BCL2 family members will require a partnership with established anti-MM regimens whose activity can potentially be further enhanced with correction of the apoptotic response system. Aim Since lenalidomide and dexamethasone (LD) is an established therapy for plasma cell cancers, we investigated if the pan-BCL2 inhibitor AT-101 (BH3 mimetic), which has high binding specificity for BCL2, MCL1 and BCL-xL, can be an effective therapeutic partner to enhance anti-MM effects of LD. Methods Human MM (KMS11, U266, OPM2) and WM (BCWM.1) cell lines along with their corresponding bortezomib resistant (BR) clones, (KMS11/BR, U266/BR, OPM2/BR and BCWM.1/BR) which were developed in our laboratory were used in this study. For gene expression profiling, the Illumina HumanHT-12 v3 whole-genome gene expression array and Nanostring nCounter mRNA quantification assays (NanoString, Seattle, WA) were utilized. Statistical analysis was conducted using R-based packages and the MeV software (TIGR). Apoptosis was measured by annexin-v/PI staining, and mitochondrial membrane permeability (MOMP) was assessed using TMRM followed by flow cytometry. Protein profiles were ascertained by western blot. Results Gene expression and immunoblot analysis of six plasma cell cancer models showed upregulation of various BCL2 family members, notably MCL1 and BCL-xL. In a dose-dependent manner, AT-101 was able to downregulate BCL2 and MCL1 and induced apoptotic cell death in MM and WM cells in a dose dependent manner. Tumor cell death was associated with caspase and PARP-1 cleavage accompanied by an increase in MOMP. This cytotoxic effect and BCL2 downregulation were further potentiated when AT-101 was combined with lenalidomide/dexamethasone (LDA). Nanostring nCounter mRNA quantification and IPA analysis revealed differential changes in the CCNA, FRZB, FYN, IRF1, PTPN11 genes in LDA treated cells. IPA canonical pathway analysis demonstrated the p53 signaling and the cyclins and cell cycle regulation pathways to be the most significantly activated by LDA therapy. Summary In summary, we describe for the first time the cellular and molecular events associated with the use of AT-101 in combination with lenalidomide/dexamethasone in preclinical models of plasma cell malignancy. This study lays the rationale for engaging and handicapping the intrinsic apoptotic system through the pan-BCL2 targeting capabilities of AT-101; thus enhancing the anti-MM effects of lenalidomide/dexamethasone. Disclosures: Foran: Celgene: Research Funding.

Novel Therapeutic Approach to Overcome Both Bortezomib- and Lenalidomide-Resistant Multiple Myeloma By Targeting TOPK/PBK

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 1763-1763
Author(s):  
Takayuki Tabayashi ◽  
Yasuyuki Takahashi ◽  
Yuta Kimura ◽  
Tatsuki Tomikawa ◽  
Tomoe Nemoto-Anan ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Cell Death ◽  
Protein Kinase ◽  
Cell Growth ◽  
Research Funding ◽  
Apoptotic Cell ◽  
Mapk Signaling ◽  
Apoptotic Cell Death ◽  
Dependent Manner ◽  
Dose Dependent

Abstract Multiple myeloma (MM) is a neoplasm of plasma cells that often remains fatal despite the use of high-dose chemotherapy with hematopoietic stem cell transplantation. In the clinical setting, the introduction of novel agents, such as proteasome inhibitors and immunomodulatory drugs, has improved the clinical outcomes of both patients with newly diagnosed MM and patients with advanced MM. However, most patients eventually relapse and develop drug resistance. T-LAK cell-originated protein kinase (TOPK), also known as PDZ-binding kinase (PBK), is a mitogen-activated protein kinase kinase (MAPKK)-like serine/threonine kinase that plays a critical role in many cellular functions, such as cell proliferation, apoptotic cell death, and inflammation, in normal tissues. Because the expression of TOPK is up-regulated during mitosis and is activated by the Cdk1/cyclin B1 complex, TOPK is thought to have a role in cytokinesis. While the expression of TOPK is very low in most normal human tissues except for testis and placenta, it is overexpressed in various malignant neoplasms, indicating its crucial role in tumorigenesis. Phosphorylation of TOPK leads to the activation of the MAPK signaling pathway including p38 and Ras extracellular signal-regulated kinase (ERK). Moreover, TOPK interacts with p53 tumor suppressor protein and inhibits its function. Ribosomal protein S6 kinase (RSK2) is a downstream target of the ERK/MAPK signaling cascade and it has a pivotal role in cell survival and proliferation. Recent studies suggest that RSK2 inhibition induces apoptotic cell death and sensitizes MM cells to lenalidomide. Suppression of p53 function is also involved in MM progression. Taken together, these data suggest that TOPK might be an attractive target for new therapeutic agents against this incurable hematological malignancy. HI-TOPK-032, which is a potent and specific inhibitor of TOPK, occupies the ATP-binding site of TOPK and thereby suppresses TOPK kinase activity. In the present study, we investigated the role of TOPK/PBK in MM as a potential therapeutic target by using HI-TOPK-032. MTSand trypan blue dye exclusion assays showed that HI-TOPK-032 inhibited the proliferation of various MM cell lines, including U266, RPMI8226, MM1.S, OPM-2, and KMS-11, in a dose- (0 to 10 mM) and time- (0 to 72 h) dependent manner. To examine the mechanisms behind the growth inhibition effect induced by HI-TOPK-032, assays for apoptotic cell death were performed; these assays demonstrated that HI-TOPK-032 induced both early and late apoptosis in MM cells. To investigate the molecular mechanisms of HI-TOPK-032-induced cell death in MM cells, the expression of various cell death-associated proteins and down-stream molecules of TOPK was examined. Western blotting analysis showed that HI-TOPK-032 arrested cell growth and induced apoptotic cell death in MM cells in a dose-dependent manner by reducing t he phosphorylation of ERK and RSK2, thereby reducing the expression of the target molecules of RSK2, i.e., MCL1 and c-Myc. Moreover, HI-TOPK-032 induced p53 expression in a dose-dependent manner. We next examined the effects of HI-TOPK-032 on bortezomib (BTZ)-resistant MM cells, which represent an urgent issue in clinics and for which a therapeutic solution is important. Interestingly, HI-TOPK-032 inhibited the proliferation of both BTZ-sensitive wild-type KMS cells and BTZ-resistant KMS cells, suggesting that BTZ resistance can be overcome by targeting TOPK. Because our results showed that HI-TOPK-032 reduced the phosphorylation of RSK2, and previous studies have suggested that RSK2 inhibition sensitized MM cells to lenalidomide, we next studied the effects of HI-TOPK-032 in combination with lenalidomide on MM cell growth. HI-TOPK-032 and lenalidomide synergisticallyinduced growth arrest in not only lenalidomide-sensitive MM cells, but also in lenalidomide-resistant cells. To determine whether HI-TOPK-032 can re-sensitize BTZ-resistant cells to the anti-MM activity of BTZ, the effects of the combination of HI-TOPK-032 and BTZ were tested using an MTS assay. Interestingly, HI-TOPK-032 was able to re-sensitize BTZ-resistant MM cells to BTZ. These results indicate that the inhibition of TOPK may serve as an attractive therapeutic option for both patients with BTZ- or lenalidomide-resistant MM. In conclusion, these data suggest that TOPK/PBK can be a promising molecular target for the treatment of MM. Disclosures Kizaki: Nippon Shinyaku Co., Ltd.: Research Funding; Ono Phranacutical Co., Ltd.: Consultancy; Kyowa Hakko Kirin Co., Ltd.: Research Funding; Chugai Phrarmaceutical Co., Ltd.: Research Funding.

JAK1/JAK2 Inhibitor, Ruxolitinib Inhibits Cell Proliferation and Induces Apoptosis in Hodgkin Lymphomas (HL) and Primary Mediastinal B-Cell Lymphomas (PMBL)

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 4886-4886 ◽  
Author(s):  
Changhong Yin ◽  
Sanghoon Lee ◽  
Janet Ayello ◽  
Carmella van de Ven ◽  
James Pao ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Cell Death ◽  
B Cell ◽  
Janus Kinase ◽  
Dependent Manner ◽  
Antiproliferative Effects ◽  
Jak2 Inhibitor ◽  
Stat Signaling ◽  
Apoptotic Genes ◽  
Dose Dependent

Abstract Abstract 4886 BACKGROUND: Hodgkin Lymphoma (HL) and Primary Mediastinal B-cell Lymphoma (PMBL) exhibit similar molecular features and pathogenesis. Both lymphoid malignancies shared similar cytogenetic abnormalities, namely 9p and 2p gains (Bentz et al., Genes Chromosomes Cancer, 2001; Joos et al., Int J Cancer 2003), and exhibit higher Janus Kinase 2 (JAK2) transcript levels with increased JAK2 activity (Green et al., Blood, 2010), suggesting aberrant activity of JAK2 and Signal Transducer and Activator of Transcription (STAT) pathways, which may play an important role in the pathogenesis of HL and PMBL. Ruxolitinib is a potent and selective JAK1/JAK2 inhibitor against myeloproliferative neoplasms (MPNs) that consistently exhibit dysregulation of the JAK1/JAK2 pathway, for reasons such as the presence of the JAK2 V617F mutation; this drug also inhibits JAK2/STAT5 signaling in vitro and in murine model of MPNs (Quintas-Cardama et al., Blood, 2010). Ruxolitinib is associated with marked and durable clinical benefits in patients with myelofibrosis (Verstovsek et al., NEJM, 2010). OBJECTIVE: Given the rationale for JAK2 inhibition in lymphoma, we designed the studies described here to evaluate the effects of Ruxolitinib on JAK2/STAT signaling pathways, cell proliferation and apoptosis in HDLM-2 (HL) and Karpas-1106P (PMBL) lymphomas. METHODS: Both HDLM-2 and Karpas-1106P cells were obtained from the DSMZ, Germany and maintained in RPMI with 20% FBS. Ruxolitinib was generously provided by Incyte Corporation, and for cytokine stimulation, Interlukin-4 (IL-4) was purchased from Invitrogen. Mono- or poly-clonal antibodies for western blotting were from Cell signaling Technology and Santa Cruz Biotech, respectively. For the effects on proliferative and apoptosis, Cell titer 96 Aqueous One solution cell proliferation assay (MTS) (Promega) and Caspase-Glo 3/7 assay (Promega) were used according to the manufacturer's instruction. Briefly, HDLM-2 and Karpas-1106P cells (0.5×106/ml) were seeded into 24-well plated and treated with vehicle (DMSO) alone or Ruxolitinib at various concentrations for 48 and 72 hours and measured by Clarity Luminescence microplate reader (BioTek) and statistical significance on this study was determined by one-tailed Student t-test. RESULTS: Ruxolitinib treatment resulted in the dose dependent inhibition of JAK2-dependent pSTAT3 (IC50: 35nM for HDLM-2; IC50: 90nM for Karpas-1106P) and pSTAT5 (IC50: 28nM for HDLM-2; IC50: 98nM for Karpas-1106P) activation. In addition, the same inhibitor potency for pSTAT6 in both HDLM-2 and Karpas-1106P cells (IC50:20nM) was observed with Ruxolitinib. The level of STAT6 phosphorylation in Karpas-1106P cells was further enhanced significantly by 10ng/ml IL-4 treatment for 10 minutes and also increased by a dose-dependent reduction of Ruxolitinib (25–400nM). The effects of Ruxolitinib on cell proliferation by MTS assay demonstrated antiproliferative effects in a dose-dependent (1–100uM) manner (p<0.05) for up to 72 hours. Consistent with the anti-proliferative effect of Ruxolitinib, Ruxolitinib induced cell death was observed with increasing doses (1–100uM) (p<0.05) in both HL and PMBL cells. The cleavage of poly adenosine diphosphate ribose polymerase (PARP), another hallmark of apoptosis, was substantially increased by Ruxolitinib in the same dose-dependent manner. We examined the effects of Ruxolitinib on the expression of anti-apoptotic genes to enhance our understanding of the effect on apoptosis, expression of two anti-apoptotic genes, Bcl-xL and Mcl-1were inhibited in a dose-dependent manner 72hours after Ruxolitinib treatment of HDLM-2 cells. These results suggested that Ruxolitinib decreases cancer cell survival by inducing programmed cell death via down-regulating the expression of anti-apoptotic genes. Taken altogether, Ruxolitinib demonstrated efficay against HDLM-2 and Karpas-1106P cells with constitutively active JAK2 signaling and effectively blocked STAT signaling in both HL and PMBL. Ruxolitinib significantly induced antiproliferative effects as well as apoptosis in HL and PMBL. CONCLUSIONS: Ruxolitinib may be a future potential targeted agent for the treatment of HL and PMBL lymphomas, and in vivo efficacy of Ruxolitinib will be evaluated in NOD/SCID mouse models of HL and PMBL lymphomas. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Detection and quantitation of malignant cells in the peripheral blood of multiple myeloma patients

Blood ◽  
1992 ◽  
Vol 80 (7) ◽  
pp. 1818-1824 ◽  
Author(s):  
D Billadeau ◽  
L Quam ◽  
W Thomas ◽  
N Kay ◽  
P Greipp ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Bone Marrow ◽  
Tumor Cells ◽  
Circulating Tumor Cells ◽  
Peripheral Blood ◽  
Alternative Assessment ◽  
Plasma Cells ◽  
Malignant Cell ◽  
Malignant Cells ◽  
Normal Peripheral Blood

Abstract One of the distinguishing features of multiple myeloma (MM) is the proliferation of plasma cells that home to the bone marrow (BM). However, there still remains some uncertainty concerning the presence of related malignant cells in the peripheral blood of myeloma patients. Using consensus oligonucleotide primers, we amplified the third complementary determining region (CDR3) of rearranged immunoglobulin heavy chain alleles from MM marrow samples by polymerase chain reaction (PCR). From the sequences of the products, we derived allele-specific oligonucleotides (ASO), and these were used in subsequent amplification reactions to detect malignant clones in the peripheral blood of myeloma patients. This method is highly specific and sensitive to 1 malignant cell in the background of 10(5) normal cells. Using this method we detected circulating malignant cells in 13 of 14 previously untreated MM patients. Furthermore, by applying ASO-PCR to artificial titrations of initial BM DNA sample into normal peripheral blood lymphocyte (PBL) DNA we were able to generate standard curves and quantitate the amount of tumor in the patient PBL. We observed a wide variation in the amount of circulating tumor between patients. In addition, we found that the incidence of circulating tumor cells was independent of BM tumor burden and stage of disease. The detection and quantitation of circulating tumor cells in the PBL of MM patients may offer an alternative assessment of the disease and may be an important consideration in the use of peripheral stem cells in bone marrow transplantation.

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