Novel CRM-1 Inhibitors for Therapy In Mantle Cell Lymphoma

Abstract Abstract 2734 Chromosomal Region Maintenance 1 (CRM1) overexpression has been associated with cancer progression and mortality in several human cancers, suggesting that activation of nuclear export may play a role in human neoplasia and may serve as a novel target for the treatment of cancers. This overexpression of CRM1 may be related to the export of most tumor suppressor and growth regulatory proteins out of the nucleus, thereby functionally inactivating them. Mantle cell lymphoma (MCL) is an aggressive histotype of B-cell non-Hodgkin lymphoma that is not yet curable. The objective of our study was to investigate the status of CRM1 in MCL, both in MCL cell lines and primary MCL cells, in comparison to normal B cells, and to evaluate the therapeutic efficiency of CRM1 inhibition in MCL in vitro and in vivo, and to elucidate the mechanism of CRM1 inhibitor-mediated MCL cell apoptosis. We used 8 established MCL cell lines and primary cells from 4 patients with relapsed/refractory MCL. KPT185 and KPT276 are novel, highly selective, drug-like small molecular CRM1 inhibitors. Western Blot analysis showed that CRM1 was expressed in both the cytoplasm and nuclei of 8 MCL cell lines. CRM1 was mainly detected in nuclei of normal resting B cells; In contrast, CRM1 was primarily detected in the cytoplasm of freshly isolated primary MCL cells from patients with relapsed/refractory MCL. In 3H-thymidine incorporation assays, inhibition of CRM1 by KPT185 resulted in a significant dose-dependent growth inhibition of 8 MCL cells, with IC50 values range between 10 nM to 120 nM. The blastoid-variant MCL cell lines (Z-138 and Rec-1) were significantly more sensitive to KPT185 than the non-blastoid variant MCL cell lines. Flow cytometry analysis with fluorescence-labeled Annexin V and propidium iodide showed that KPT185 induced MCL cells apoptosis in both time- and dose-dependent manners, but had no effect on cell cycle arrest. MCL cells treated with KPT185 for 12 hours showed caspase 3 activation and PARP cleavage. As shown in Western blot and confocal microscopy, blocking CRM1 activity by KPT185 in MCL cells up-regulated the protein expression of p53, a known CRM1-mediated export protein, and also induced CRM1 translocation to the nucleus and decreased CRM1 expression. In severe combined immunodeficient (SCID) mice bearing palpable Z-138 tumors, treatment with KPT-276 (similar structure to KPT-185 but improved animal pharmacokinetics), 50mg/kg or 150 mg/kg PO QDx5 each week, or cyclophosphamide 100 mg/kg on days 1–3, was initiated. Tumor growth was significantly inhibited (>75%) in all of treatment groups compared with vehicle control. Neutropenia and other cytotoxic-agent specific effects have not been observed in treated animals. In conclusion, CRM1 inhibitors inhibited growth of MCL cells in vitro and in vivo, and induced apoptosis of MCL cells via inhibition of CRM1 expression and blockage of its translocation with functional nuclear proteins. Our data suggest that novel CRM1 inhibitors provide a potential therapy for patients with relapsed/refractory MCL. Disclosures: No relevant conflicts of interest to declare.

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BET bromodomain inhibitor birabresib in mantle cell lymphoma: in vivo activity and identification of novel combinations to overcome adaptive resistance

ESMO Open ◽

10.1136/esmoopen-2018-000387 ◽

2018 ◽

Vol 3 (6) ◽

pp. e000387 ◽

Cited By ~ 10

Author(s):

Chiara Tarantelli ◽

Elena Bernasconi ◽

Eugenio Gaudio ◽

Luciano Cascione ◽

Valentina Restelli ◽

...

Keyword(s):

Mantle Cell Lymphoma ◽

Cell Lines ◽

Cell Lymphoma ◽

Antitumour Activity ◽

Single Agent ◽

Treatment Strategies ◽

Bet Inhibitor ◽

Mantle Cell

BackgroundThe outcome of patients affected by mantle cell lymphoma (MCL) has improved in recent years, but there is still a need for novel treatment strategies for these patients. Human cancers, including MCL, present recurrent alterations in genes that encode transcription machinery proteins and of proteins involved in regulating chromatin structure, providing the rationale to pharmacologically target epigenetic proteins. The Bromodomain and Extra Terminal domain (BET) family proteins act as transcriptional regulators of key signalling pathways including those sustaining cell viability. Birabresib (MK-8628/OTX015) has shown antitumour activity in different preclinical models and has been the first BET inhibitor to successfully undergo early clinical trials.Materials and methodsThe activity of birabresib as a single agent and in combination, as well as its mechanism of action was studied in MCL cell lines.ResultsBirabresib showed in vitro and in vivo activities, which appeared mediated via downregulation of MYC targets, cell cycle and NFKB pathway genes and were independent of direct downregulation of CCND1. Additionally, the combination of birabresib with other targeted agents (especially pomalidomide, or inhibitors of BTK, mTOR and ATR) was beneficial in MCL cell lines.ConclusionOur data provide the rationale to evaluate birabresib in patients affected by MCL.

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GST-n and Nitric Oxide: A Novel Approach to Mantle Cell Lymphoma Therapy.

Blood ◽

10.1182/blood.v114.22.3729.3729 ◽

2009 ◽

Vol 114 (22) ◽

pp. 3729-3729

Author(s):

Heather Gilbert ◽

John Cumming ◽

Josef T. Prchal ◽

Michelle Kinsey ◽

Paul Shami

Keyword(s):

Nitric Oxide ◽

Mantle Cell Lymphoma ◽

Cell Lines ◽

Cell Lymphoma ◽

Xenograft Model ◽

Malignant Cells ◽

Mantle Cell ◽

Tumor Viability

Abstract Abstract 3729 Poster Board III-665 Mantle cell lymphoma (MCL) is a well defined B-cell non-Hodgkin lymphoma characterized by a translocation that juxtaposes the BCL1 gene on chromosome 11q13, which encodes cyclin D1 (CD1), next to the immunoglobulin heavy chain gene promoter on chromosome 14. The resulting constitutive overexpression of CD1 leads to a deregulated cell cycle and activation of cell survival mechanisms. In addition, the gene which encodes GST-n, an enzyme that has been implicated in the development of cancer resistance to chemotherapy, is also located on chromosome 11q13 and is often coamplified along with the BCL1 gene in MCL (1). These two unique biological features of MCL - the overproduction of cyclin D1 and GST-n – may be involved in the carcinogenesis, tumor growth and poor response of this disease to treatment, and they offer potential mechanisms for targeted anti-cancer therapy. Nitric oxide (NO) is a biologic effector molecule that contributes to a host's immune defense against microbial and tumor cell growth. Indeed, NO is potently cytotoxic to tumor cells in vitro (2–4). However, NO is also a potent vasodilator and induces hypotension, making the in vivo administration of NO very difficult. To use NO in vivo requires agents that selectively deliver NO to the targeted malignant cells. A new compound has recently been developed that releases NO upon interaction with glutathione in a reaction catalyzed by GST-n. JS-K seeks to exploit known GST-n upregulation in malignant cells by generating NO directly in cancer cells, and it has been shown to decrease the growth and increase apoptosis in vitro in AML cell lines, AML cells freshly isolated from patients, multiple myeloma cell lines, hepatoma cells and prostate cancer cell lines (3, 5–7). JS-K also decreases tumor burden in NOD/SCID mice xenografted with AML and multiple myeloma cells (5, 7). Importantly, JS-K has been used in cytotoxic doses in the mouse model without significant hypotension. To evaluate whether JS-K treatment has anti-tumor activity in MCL, the human MCL cell lines Jeko1, Mino, Granta and Hb-12 were grown with media only, with JS-K at varying concentrations and with DMSO as an appropriate vehicle control. For detection of apoptotic cells, cell-surface staining was performed with FITC-labeled anti–Annexin V and PI. Cell growth was evaluated using the Promega MTS cytotoxicity assay. Results show that JS-K (at concentrations up to 10 μM) inhibits the growth of MCL lines compared to untreated controls, with an average IC50 of 1 μM. At 48 hours of incubation, all cell lines showed a significantly greater rate of apoptosis than untreated controls. A human MCL xenograft model was then created by subcutaneously injecting two NOD/SCID IL2Rnnull mice with luciferase-transfected Hb12 cells. Seven days post-injection, one of the mice was treated with JS-K at a dose of 4 μmol/kg (expected to give peak blood levels of around 17 mM in a 20 g mouse). Injections of JS-K were given intravenously through the lateral tail vein 3 times a week. The control mouse was injected with an equivalent volume of micellar formulation (vehicle) without active drug. The Xenogen bioluminescence imaging clearly showed a difference in tumor viability, with a significantly decreased signal in the JS-K treated mouse. Our studies demonstrate that JS-K markedly decreases cell proliferation and increases apoptosis in a concentration- and time-dependent manner in mantle cells in vitro. In a xenograft model of mantle cell lymphoma, treatment with JS-K results in decreased tumor viability. Proposed future research includes further defining the molecular basis of these treatment effects; using this therapy in combination with other cancer treatments both in vitro and in vivo; and studying JS-K treatment in MCL patients. Disclosures: Shami: JSK Therapeutics: Founder, Chief Medical Officer, Stockholder.

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The Effects of PI3K-δ/γ Inhibitor, Duvelisib, in Mantle Cell Lymphoma in Vitro and in Patient-Derived Xenograft Studies

Blood ◽

10.1182/blood.v128.22.3016.3016 ◽

2016 ◽

Vol 128 (22) ◽

pp. 3016-3016 ◽

Cited By ~ 4

Author(s):

Jack Wang ◽

Victoria Zhang ◽

Taylor Bell ◽

Yang Liu ◽

Hui Guo ◽

...

Keyword(s):

Growth Inhibition ◽

Mantle Cell Lymphoma ◽

Cell Lines ◽

Cell Lymphoma ◽

Oral Gavage ◽

Patient Derived Xenograft ◽

Pdx Model ◽

Mantle Cell

Abstract Background: Mantle cell lymphoma (MCL) is an incurable subtype of B-cell lymphoma. Ibrutinib, a first-in-class, once-daily, oral covalent inhibitor of Bruton's tyrosine kinase (BTK) was approved by the FDA for the treatment of MCL in patients previously treated. In our prior multicenter Phase 2 clinical trial, the overall response rate in relapsed/refractory MCL was 68%, with a median progression-free survival (PFS) of 13.9 months. However, the majority of MCL patients treated with ibrutinib relapsed; in these relapsed patients, the one-year survival rate was only 22%. Therefore, there exists an urgent need for additional novel targeted therapies to improve the mortality rate in these patients. In this study, we assessed the in vitro and in vivo effects of duvelisib, a PI3K-δ,-γ inhibitor, in MCL. Methods: The PI3K/AKT/mTOR and other cell survival signaling pathways were investigated by RNASeq and reverse phase protein array (RPPA) in ibrutinib-sensitive and -resistant MCL samples. The expression of PI3K isoforms, α, β, γ, and δ was tested in 11 MCL cell lines, patient and patient-derived xenograft (PDX) MCL cells by western blot analysis. We then investigated the growth inhibition and apoptosis of duvelisib (IPI-145, Infinity Pharmaceuticals, Inc.) in MCL cells by CellTiter-Glo® Luminescent Cell Viability Assay (Promega) and Annexin V-binding assay (BD Biosciences). We established a primary MCL-bearing PDX model and passaged the primary MCL tumor to next generations. Mice were administrated with 50 mg/kg duvelisib daily by oral gavage. Tumor burden and survival time were investigated in the MCL-PDX model. Results: We found that the PI3K/AKT/mTOR signaling pathway was activated in both primary and acquired ibrutinib-resistant MCL cell lines and PDX MCL cells. We immunoblotted PI3K isoforms, α, β, γ, and δ in 11 MCL cell lines and the result demonstrated that both ibrutinib-sensitive and ibrutinib-resistant MCL cells dominantly expressed PI3K-δ and -γ. Next, we tested the effects of duvelisib on these MCL cells. Duvelisib had effects on the growth inhibition and apoptosis in both ibrutinib-sensitive and ibrutinib-resistant MCL cells as good as the PI3K-δ inhibitor, idelalisib (Cal-101, GS-1101). The PI3K-δ isoform could play a very important role in PI3K-mediated signals in MCL. We then investigated the effects of duvelisib in vivo through our established MCL-bearing PDX mouse models. These models are created by inoculating the primary tumor cells from MCL patients into a human fetal bone chip implanted into NSG mice to provide a microenvironment that reconstitutes the human environment. MCL tumor mass was then passaged to next generations for therapeutic investigation of duvelisib. Mice were treated with 50 mg/kg duvelisib daily by oral gavage. Our data demonstrated that duvelisib significantly inhibited tumor growth and prolonged survival of MCL-PDX mice. Conclusion: Duvelisib, an oral dual inhibitor of PI3K-δ,-γ, inhibits MCL growth both in vitro and in PDX mice. These preclinical results suggests duvelisib may be effective in the treatment of patients with relapsed/refractory MCL. Disclosures No relevant conflicts of interest to declare.

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In Vitro and In Vivo Anti Lymphoma Effect of GX15-070 in Mantle Cell Lymphoma.

Blood ◽

10.1182/blood.v108.11.4756.4756 ◽

2006 ◽

Vol 108 (11) ◽

pp. 4756-4756 ◽

Cited By ~ 1

Author(s):

Gwyn Bebb ◽

Huong Muzik ◽

Sophia Nguyen ◽

Don Morris ◽

Douglas A. Stewart

Keyword(s):

Mantle Cell Lymphoma ◽

Cell Line ◽

Cell Lines ◽

Cell Lymphoma ◽

B Cell Lymphoma ◽

Cytotoxic Agents ◽

In Vivo Experiments ◽

Mantle Cell

Abstract Introduction Mantle cell lymphoma (MCL), an incurable B cell lymphoma, consistently over expresses bcl-2 despite not carrying the t(14;18). The attenuation of apoptosis by bcl-2 is thought to contribute to the malignant process and increase resistance to some cytotoxic agents. We recently demonstrated that GX15-070, a small molecular inhibitor of the BH3 binding groove of bcl-2, has activity against MCL cell lines in vitro. We set out to assess the effect of GX15-070 alone and in combination with Vincristine on the viability of MCL cells in vitro and in vivo. Methods 3 previously characterized bcl-2 over expressing MCL cell lines (JVM-2, Hbl-2, granta) were used. Cells were grown in standard media and exposed to a range of concentrations of GX15-070 with and without Vincristine. Dose-response was assessed by measuring viability at 48 hours using the WST-1 assay. In vivo experiments were conducted on immune deficient mice in which 5×106 cells were injected in the flank then treated IV with GX15-070 (q 2days × 5 doses), Vincristine (q4 days × 3 doses) or both starting 5 days later. Tumours were measured three times weekly. Results All three MCL cell lines over-expressed bcl-2 by western blot. Each MCL cell line showed sensitivity to GX15-070 at a range of concentrations. The addition of GX15-070 to low dose Vincristine (10−6) caused significant growth inhibition of each MCL cell line (see table 1). Discussion Our results demonstrate that using GX15-070 to target bcl-2 is an effective anti neoplastic approach against MCL cell lines in vitro. In addition, our results suggest that combining Vincristine and GX15-070 is a promising strategy in treating MCL. In vivo experiments to confirm this additive activity are still ongoing and will be presented in full. Initial impressions suggest that there is a rationale for the addition of GX15-070 to current cytotoxic regimens used to treat MCL in the setting of clinical trials. Table 1: Effect of Vincristine and GX15-070 on in vitro growth of 3 MCL cell lines Growth as % age of Control Cell Line JVM-2 HBL-2 Granta Vincristine alone (10-6 mg/ml) 92% 48% 89% GX15-070 alone (0.08 uM) 75% 76% 60% Vincristine 10-6 mg/ml and GX15-070 0.08 uM 52% 24% 52%

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The Nucleoside Analogue Acadesine Exerts Antitumoral Activity and Cooperates with Conventional Agents In In Vitro and In Vivo Models of Mantle Cell Lymphoma

Blood ◽

10.1182/blood.v116.21.3918.3918 ◽

2010 ◽

Vol 116 (21) ◽

pp. 3918-3918

Author(s):

Arnau Montraveta ◽

Mercè de Frías ◽

Clara Campàs ◽

Elias Campo ◽

Gael Roue ◽

...

Keyword(s):

Mantle Cell Lymphoma ◽

Cell Lines ◽

Nucleoside Analogue ◽

Cell Lymphoma ◽

Primary Cultures ◽

Antitumoral Activity ◽

In Vivo Models ◽

Mantle Cell

Abstract Abstract 3918 Mantle cell lymphoma (MCL) is a mature B-cell neoplasm characterized by the t(11;14)(q13:q32) that involves cyclin D1 overexpression and consequent cell cycle deregulation at the G1 phase. This entity is generally characterized by an aggressive course and a bad prognosis. Recently, a specific subtype of MCL has been described, showing best outcomes and that might be managed more conservatively than conventional MCL. These cases are characterized by non-nodal presentation, predominantly hypermutated IgVH, lack of genomic complexity, and absence of SOX11 expression. Acadesine is a nucleoside analogue initially developed as a cardioprotective agent, and which has shown a wide range of metabolic effects, including the activation of AMP-activated protein kinase (AMPK). Acadesine was shown to induce apoptosis in primary cells from several B lymphoid neoplasms and has been entered in a phase I/II clinical trial with relapsed/refractory chronic lymphocytic leukemia (CLL) patients. This clinical study has shown that acadesine plasmatic levels in the micro molar range are achievable and safe when CLL patients are treated with the drug. To evaluate the antitumoral properties of acadesine in MCL, we exposed a set of 11 MCL primary cultures and 9 MCL cell lines for up to 48h with increasing doses of the drug. Cytotoxicity and cytostatic effects were then assessed by flow cytometry detection of annexinV/propidium iodide labeling and MTT proliferation assay, respectively. In both MCL cell lines and MCL primary cultures, we observed a heterogeneous response to the drug, with no correlation to common genetic alterations such as deletion/mutation of P53, ATM or P16 genes. JVM2, Jeko-1, Rec-1 and UPN-1 were the more sensitive cell lines, with a mean lethal dose 50 (LD50) of 1.57 mM at 24 h and 0.95 mM at 48h, while 2 cell lines (HBL-2 and Granta-519) showed a primary resistance to the compound (LD50 > 50 mM). Among MCL primary cultures, acadesine showed selective cytotoxic activity against malignant B cells while sparing accompanying T cells. Of note, those cases corresponding to the indolent MCL group showed increased sensitivity to the drug at 24h of treatment, when compared to conventional MCL cases (p=0.03). We observed that acadesine efficiently activates the intrinsic apoptotic pathway in MCL cells by modulating Bcl-2 family protein levels, leading to conformational activation of Bax and Bak, mitochondrial depolarization, generation of reactive oxygen species and caspases processing. In drug combination assays, acadesine showed a synergistic effect when combined with Rituximab, being the Rituximab-acadesine combination more potent than other Rituximab-based polychemotherapies such as R-bendamustine and R-CHOP. Finally, a daily administration of 400mg/kg acadesine in mice previously inoculated with a MCL xenotransplant significantly reduced tumor burden when compared to control animals, as soon as 7 days of treatment. In summary, these results suggest that acadesine exerts significant antitumoral activity in both in vitro and in vivo model of MCL, and may represent an attractive model for the design of a new therapeutic approach for this entity, especially in patients presenting with the indolent form. Disclosures: de Frías: Advancell therapeutics: Employment. Campàs:Advancell therapeutics: Employment.

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CD24/Siglec-10 "Don't Eat Me" Signal Blockade Is a Potential Immunotherapeutic Target in Mantle-Cell Lymphoma

Blood ◽

10.1182/blood-2021-154086 ◽

2021 ◽

Vol 138 (Supplement 1) ◽

pp. 2276-2276

Author(s):

Andrea Aroldi ◽

Mario Mauri ◽

Matteo Parma ◽

Elisabetta Terruzzi ◽

Marilena Fedele ◽

...

Keyword(s):

B Cell ◽

Mantle Cell Lymphoma ◽

Cell Lines ◽

Cell Lymphoma ◽

Target Cells ◽

Solid Cancer ◽

Dismal Prognosis ◽

Mantle Cell

Abstract Introduction Mantle-cell lymphoma (MCL) is a B-cell non-Hodgkin Lymphoma (NHL) characterized by heterogenous behavior, ranging from indolent phenotype to highly aggressive and drug resistant one with dismal prognosis. Drug resistance may be generated by Tumor Microenvironment (TME), owing that Tumor-Associated Macrophages (TAM) are pathologically functional in providing survival signals to MCL cells (Pham, Front Oncol. 2018). Recently, "Don't Eat Me" signal (DEMs) blockade with anti-CD47 monoclonal Antibody (moAb) showed promising activity in pretreated NHL, through increase of phagocytosis by TAM (Advani, NEJM. 2019). CD24 was also demonstrated to be involved in DEMs and, in a preclinical model of solid cancer, blocking the CD24/Siglec-10 interaction provided an improvement of M2-like TAM-mediated phagocytosis in vitro and an increase of survival in vivo (Barkal, Nature. 2019). CD24 can be expressed in some phases of B-cell differentiation and MCL derives from a B-cell precursor with upregulated CD24. To date, there are no functional studies showing an improvement of phagocytosis through CD24/Siglec-10 pathway inhibition in hematologic malignancies and MCL. Here, we present our in vitro results of CD24/Siglec-10 DEMs blockade in MCL subset. Methods A panel of MCL cell lines (Jeko-1, Granta-519, Mino) has been analyzed for CD24 surface expression by flow cytometry (FC) (clone SN3). Consequently, we performed co-culture experiments with MCL cell lines and macrophages from healthy donors. Briefly, Peripheral Blood Mononucleated Cells (PBMC) were collected from healthy volunteers through density gradient centrifugation technique. CD14+ monocytes were isolated through CD14 Microbeads isolation kit and cultured in plates with 50 ng/ml human GM-CSF for 7-9 days. In order to create M2-like Siglec-10+ TAM, 50 ng/ml human IL-10 and 50 ng/ml human TGF-β 1 were added on days 3-4 of differentiation until use on days 7-9. Siglec-10 expression on TAM was checked by FC (clone 5G6). M2-like macrophages were then collected and co-cultured with CFSE-labelled MCL target cells for 1-2 hours in a serum-free medium. Anti-CD24 moAb (clone SN3) or the appropriate IgG 1 isotype control were added at a concentration of 10 μg/ml. Phagocytosis was then stopped on ice and CD11b-PE staining (anti-CD11b moAb, clone REA713) was performed to identify human macrophages by FC. Phagocytosis was measured as the number of CD11b+/CFSE+ macrophages, quantified as a percentage of the total CD11b+ macrophages. Each phagocytosis reaction was performed in technical triplicate and phagocytosis was normalized to the highest technical replicate per donor in order to consider raw phagocytic level among donor-derived macrophages. Results MCL cell lines express surface CD24 by FC, with higher levels in Mino cell line (Figure 1A). Differentiated M2-like macrophages showed an upregulation of Siglec-10 expression after immunosuppressive stimuli, which is fundamental owing that Siglec-10 is the ligand of CD24 (Figure 1B). As pertains to the phagocytic assay, we documented an improvement of phagocytosis when M2-like macrophages and MCL cell lines were co-cultured together with anti-CD24 moAb (Figure 2 and Figure 3A). Furthermore, it is worth mentioning that phagocytosis seemed to be much higher in MCL cell lines with higher surface levels of CD24 (e.g., Mino), presenting increased number of CD11b+/CFSE+ M2-like TAM by FC (Figure 3B). Conclusions MCL was found to be sensitive to CD24/Siglec-10 DEMs blockade when co-cultured with M2-like macrophages in vitro. We can argue that most of the observed increase of phagocytosis after the addition of anti-CD24 moAb may be secondary to loss of CD24 signalling rather than Fc-mediated opsonization, as already documented in previous analysis about solid cancer (Barkal, Nature. 2019). We can therefore hypothesize that the blockade of this DEMs pathway can improve phagocytosis in a non-opsonization manner in NHL as well. Furthermore, CD24 surface density seemed to be positively correlated to the intensity of phagocytic activity, suggesting that MCL subtypes expressing higher CD24 levels are much more dependent on this DEMs pathway than others with low CD24 density. Overall, CD24 turned out to be a potential immunotherapeutic target in MCL, aiming at improving innate immune system through DEMs blockade. In vivo studies are needed to confirm the activity we documented in vitro in this NHL subset. Figure 1 Figure 1. Disclosures Gambacorti-Passerini: Bristol-Myers Squibb: Consultancy; Pfizer: Honoraria, Research Funding.

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Bortezomib Is Synergistic with Rituximab and Cyclophosphamide in Inducing Apoptosis of Mantle Cell Lymphoma Cells In Vitro and In Vivo.

Blood ◽

10.1182/blood.v110.11.4514.4514 ◽

2007 ◽

Vol 110 (11) ◽

pp. 4514-4514

Author(s):

Liang Zhang ◽

Yuankai Shi ◽

Xiaohong Han ◽

Jing Yang ◽

Jianfei Qian ◽

...

Keyword(s):

Mantle Cell Lymphoma ◽

Tumor Cells ◽

Cell Lines ◽

Primary Tumor ◽

Cell Lymphoma ◽

Fixed Dose ◽

Mantle Cell ◽

Induced Apoptosis

Abstract Introduction: Mantle cell lymphoma (MCL) is an aggressive B-cell lymphoma with poor clinical outcome. Although frontline therapy induces a high rate of complete remission, relapse is inevitable and new regimens are needed for relapsed MCL. The proteasome inhibitor bortezomib (BTZ) induces apoptosis and sensitizes MCL cells to chemotherapy in relapsed MCL, but as a single agent, response rate is low, duration of response is short and side effects are severe. Here we evaluated whether BTZ is additive or synergistic with cyclophosphamide (CTX) and rituximab (RTX). Material and Methods: Four human MCL cell lines SP53, MINO, Grant 519, and Jeko-1 and freshly isolated primary tumor cells from three MCL patients were treated with BTZ, CTX, RTX individually or in combination of RTX and CTX (RC), or BTZ plus RTX and CTX (BRC regimen). Cell proliferation and apoptosis were evaluated to determine if there was additive or synergistic effect of the BRC regimen. Western blot analysis was used to elucidate the molecular mechanism by which BTZ, RTX, CTX, RC and BRC induces apoptosis in MCL cells. In addition, in vivo experiments using severe combined immunodeficiency mice with human mantle cell lymphoma xenografts were performed to examine the in vivo efficacy of the regimen to control the growth of and eradicate MCL cells. Results: BTZ and CTX as single agents inhibited the growth of MCL cell lines in a dose-dependent manner (P < 0.01). The IC50 (inhibitory concentration at 50%) for BTZ and for CTX were between 10 and 20 nM and between 5 and 20 mM, respectively. Increasing doses of BTZ with a fixed dose of RTX (10 μg/mL) and CTX (10 mM) resulted in markedly synergistic growth inhibition of MCL cells (P < 0.01). The BRC regimen induced apoptosis in about 69.7% of MCL cell lines and 92.6% of primary tumor cells (P < 0.05 and P < 0.01, compared with those induced by BTZ, RTX, CTX or RC). Furthermore, western blotting analysis showed that BRC induced apoptosis earlier via activation and cleavage of caspases-8, -9, and -3, and PARP as compared with BTZ, RTX, CTX or RC. The pan-caspase inhibitor z-VAD-FMK completely blocked apoptosis induced by BRC. In vivo studies demonstrated that BRC regimen eradicated subcutaneous tumors in MCL-bearing SCID mice and significantly prolonged the long-term event-free survival up to 10 weeks in 70% of the mice, whereas all tumor-bearing mice receiving BTZ, RTX, CTX or RC or PBS (control) died of aggressive MCL within 6 weeks. Conclusion: Cytoreductive chemotherapy with both BTZ and anti-CD20 antibody effectively inhibited the growth and induced apoptosis of MCL cells in vitro and in vivo. Bortezomib-rituximab-cyclophosphamide (BRC) regimen may offer a better therapeutic modality for MCL patients. Thus, our data lay the basis for a clinical trial in relapsed MCL using the BRC combination treatment.

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FTY720 Increases CD74 Expression and Sensitizes Mantle Cell Lymphoma Cells to Milatuzumab-Mediated Cell Death

Blood ◽

10.1182/blood.v118.21.600.600 ◽

2011 ◽

Vol 118 (21) ◽

pp. 600-600

Author(s):

Lapo Alinari ◽

Emilia Mahoney ◽

John T. Patton ◽

Xiaoli Zhang ◽

Lenguyen Huynh ◽

...

Keyword(s):

Monoclonal Antibody ◽

Cell Death ◽

Mantle Cell Lymphoma ◽

Cell Lines ◽

Median Survival ◽

Combination Treatment ◽

Cell Lymphoma ◽

Mantle Cell

Abstract Abstract 600 Mantle cell lymphoma (MCL) is an aggressive B-cell malignancy with a short median survival despite multimodal therapy. FTY720, an immunosuppressive drug approved for the treatment of multiple sclerosis, promotes MCL cell death via down-modulation of phospho-Akt and Cyclin D1, and subsequent cell cycle arrest (1). However, the mechanism of FTY720-mediated MCL cell death remains to be fully clarified. Here we show features of autophagy blockage by FTY720 treatment, including accumulation of autolysosomes, increased LC3-II and p62 levels. FTY720 is phosphorylated in vivo by sphingosine kinase 2 and converted to p-FTY720, which binds to sphingosine-1-phosphate (S1P) receptors. A non-phosphorylatable FTY720 derivative (OSU-2S) was recently developed at the Ohio State University (2): OSU-2S treatment induces MCL cell death and shows features of autophagy blockage that led us to conclude that FTY720 phosphorylation and its interaction with SP1 receptors are not required for FTY720-mediated cell death and blockage of autophagy in MCL cells. We also demonstrate that FTY720-induced cell death is mediated by lysosomal membrane permeabilization with subsequent translocation of lysosomal hydrolases to the cytosol. FTY720-mediated disruption of the autophagic-lysosomal pathway led to increased levels of CD74, a potential therapeutic target in MCL that is degraded in the lysosomal compartment. We have recently reported CD74 to be expressed on MCL cells and that milatuzumab (Immunomedics, Morris Plains, NJ), a humanized anti-CD74 monoclonal antibody, has significant anti-MCL activity in vitro and in vivo (3). This finding provided the rationale for examining combination therapy with FTY720 and milatuzumab. The in vitro survival of 4 MCL cell lines treated with FTY720, immobilized milatuzumab, and the combination was determined at 24 hours by Annexin-V/PI staining and flow cytometry. Incubation of 4 MCL cell lines with FTY720 and milatuzumab (1 μg/ml) resulted in a statistically significant decrease in cell viability compared to either agent alone for each of the four cell lines (P< 0.01), despite using FTY720 at concentrations lower than the LC50 previously published [Jeko-1 FTY720: 10 μM (LC50: 12.5 μM), Z-138 and UPN-1: 6 μM (LC50: 7.5 μM); Mino 3.75 μM (LC50: 7.5μM)] (1). Notably, combination treatment resulted in synergistic killing in cell lines derived from patients with blastoid variant MCL (Jeko-1, Z-138, UPN-1), despite the fact that both FTY720 and milatuzumab as single agents showed only modest activity. Incubation of primary tumor cells from 6 MCL patients (3 blastoid variant and 3 classic MCL) with FTY720 (2.5 μM, LC50: 5 μM) and miltauzumab induced an average 78.5% cell death compared to 47% of FTY720 treated cells and 50% the milatuzumab-treated cells (P=0.0005 and P=0.0014, respectively). To examine the in vivo activity of FTY720 and milatuzumab, a preclinical model of human MCL using the SCID (CB17 scid/scid) mouse depleted of NK cells was used. In this model, i.v. injection of 40×106 JeKo cells results in disseminated MCL 3 weeks after engraftment. The primary end-point was survival, defined as the time to develop cachexia/wasting syndrome or hind limb paralysis. Mice (n=10/group) were treated starting at day 15 post engraftment. Twenty control mice received either placebo (saline) or trastuzumab (15 mg/kg) treatment. The third group was treated with FTY720 (5 mg/kg) every day for 2 weeks via i.p injection. The fourth group received milatuzumab (15 mg/kg) every three days, via i.p. injection. The fifth group received the combination of FTY720 and milatuzumab. The median survival for the combination-treated group was 36 days (95% CI:31,36), compared to 28 days for the saline-treated mice (95% CI:24,31), 27 days for the trastuzumab-treated mice (95% CI:23,29), 31 days for the FTY720-treated mice (95% CI:28,32), and 33.5 days for the milatuzumab-treated mice (95% CI:23,34). The combination treatment significantly prolonged survival of this group compared to control groups (P<0.0001), FTY720 (P=0.0001) and milatuzumab (P=0.0048). The most clinically relevant aspect of these findings is that we demonstrate that a potent anti-MCL agent (FTY720) has also the ability to modulate a druggable target (CD74) by preventing its degradation in the autophagic-lysosomal pathway. We believe these findings support clinical evaluation of this combination in patients with MCL. Disclosures: Off Label Use: fty720 immunosupressive drug milatuzumab fully humanized anti-CD74 monoclonal antibody. Goldenberg:Immunomedics: Equity Ownership, Immunomedics owns milatuzumab, Patents & Royalties.

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Newer-Generation HSP90 Inhibitors Have Potent Activity Against Human Mantle Cell Lymphoma in Vitro and in Vivo

Blood ◽

10.1182/blood.v120.21.1651.1651 ◽

2012 ◽

Vol 120 (21) ◽

pp. 1651-1651

Author(s):

Oliver Weigert ◽

Diederik van Bodegom ◽

Liat Bird ◽

Amy Saur ◽

Trevor Tivey ◽

...

Keyword(s):

Cell Death ◽

Cyclin D1 ◽

Mantle Cell Lymphoma ◽

Cell Lines ◽

Cell Lymphoma ◽

Cell Killing ◽

Hsp90 Inhibitors ◽

Mantle Cell

Abstract Abstract 1651 Mantle cell lymphoma (MCL) is associated with particularly poor outcome, with long-term survival achieved in less than 40% of patients. In addition to the characteristic t(11;14) that results in overexpression of cyclin D1, a variety of other molecular pathways are dysregulated in MCL. Cyclin D1 is a known client of heat shock protein 90 (HSP90), suggesting that inhibitors of HSP90 may destabilize cyclin D1 and have activity in this disease. Yet, first-generation HSP90 inhibitors such as 17-AAG generally lack potency in MCL cell lines. We assessed the pre-clinical activity of second- (NVP-AUY922, PU-H71) and third-generation (NVP-HSP990) HSP90 inhibitors, which have greater potency and superior in vivo pharmacokinetics, in the MCL cell lines Granta519, JeKo1, MAVER1, Rec1, and Z-138. To define the genetics of these lines, we utilized an exon-capture followed by next-generation sequencing approach to identify single nucleotide variants and insertions/deletions across the entire coding sequence of 197 genes known to be recurrently altered in lymphoid malignancies. Sequencing to a median depth of coverage∼400 recovered alterations previously described in MCL (e.g. in ATM, RB1, TP53, NOTCH1) as well as variants in genes that have not previously been associated with MCL (e.g. in MLL2, KDM6A, FLT3, IKZF3, JAK3, RFXAP). Dose response curves of these cell lines treated with structurally diverse HSP90 inhibitors showed 10–100-fold greater potency for NVP-AUY922 (IC50, 3–11 nM), NVP-HSP990 (IC50, 5–24 nM) and PU-H71 (IC50, 40–287 nM), compared with 17-AAG (IC50, 29–1503 nM). In vitro exposure of all lines to 50 nM AUY922 resulted in G0/G1 cell cycle arrest within 6–8 hrs followed by apoptosis within 24–72 hours. Immunoblotting after exposure to AUY922 demonstrated rapid reductions in HSP90 client proteins, including cyclin D1, CDK4 and AKT, in all lines as well as accumulation of HSP70 in all lines except REC1, which harbors an HSP70 locus deletion. Cell killing by AUY922 (based on Annexin V/PI flow cytometry, caspase 3/7 activation and PARP cleavage) varied between cell lines, with Granta519 being the most sensitive (>50% cell death after 24 hr exposure) and Rec1 being the least sensitive (<15% cell death under the same conditions). Co-culture of Granta519, JeKo1, and Z-138 cells with bone marrow stroma had no effect on killing by AUY922, suggesting that HSP90 inhibition may overcome cell non-autonomous pathways that support resistance to other antineoplastic agents. To build on these findings in vivo, we xenografted luciferized MAVER1 (harbors TP53 D281E and JAK3 V722I mutations) and Z-138 (TP53 and JAK3 wild-type) cells into SCID beige mice (10 million cells per mouse). Upon evidence of measurable engraftment, mice (10 per arm) were randomized to receive either AUY922 (50 mg/kg by tail vein injection thrice weekly) or vehicle. Tumors were analyzed from sentinel mice that were sacrificed after 5 days of treatment. Tumors from mice receiving AUY922 had complete loss of cyclin D1 and Ki67 staining by immunohistochemistry. 18F-FLT PET scanning performed on mice xenografted with Z-138 cells demonstrated ∼75% reduction in activity after 5 days of AUY922 treatment. Consistent with these findings, tumor growth was significantly slowed among AUY922-treated animals for both lines, which translated into a survival advantage (p<0.01 for MAVER1 and p=0.03 for Z-138). Finally, in an effort to enhance cell killing, we combined AUY922 with compounds in clinical use for MCL. In JeKo1, MAVER1, Rec1 and Z-138 cells, combinations with AUY922 were either antagonistic (with cytarabine or doxorubicin) or lacked synergistic effects (with bortezomib). AUY922 also failed to block the accumulation of MCL1 induced by exposure to bortezomib. Thus, appropriate drug combination partners for AUY922 in MCL remain to be determined. In conclusion, newer-generation HSP90 inhibitors such as AUY922 have significant single-agent activity across a genetically diverse spectrum of MCLs, can target cyclin D1, CDK4, AKT and other drivers of malignant phenotype, and warrant evaluation in clinical trials. Disclosures: Weinstock: Novartis: Consultancy, Research Funding.

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Atiprimod Inhibits Growth of Mantle Cell Lymphoma In Vitro and In Vivo and Induces Apoptosis Via Activation of the Mitochondrial Pathway.

Blood ◽

10.1182/blood.v108.11.2514.2514 ◽

2006 ◽

Vol 108 (11) ◽

pp. 2514-2514

Author(s):

Michael Wang ◽

Liang Zhang ◽

Xiaohong Han ◽

Jin Yang ◽

Jianfei Qian ◽

...

Keyword(s):

Mouse Model ◽

Cell Lines ◽

Cell Lymphoma ◽

Caspase 9 ◽

Healthy Donors ◽

Mantle Cell ◽

Induced Apoptosis ◽

Dose Dependent

Abstract Mantle cell lymphoma (MCL) has poor outcome and is a therapeutic challenge. Atiprimod, a cationic amphiphilic compound, inhibits the proliferation of most human tumor cell lines. Our study was undertaken to evaluate the therapeutic efficacy of Atiprimod on MCL cells and elucidate the mechanism by which it induces cell apoptosis. Four human MCL cell lines, SP53, MINO, Grant 519, and Jeko-1; freshly isolated primary MCL cells from three MCL patients; and normal peripheral blood mononuclear cells (PBMCs) from five healthy donors were treated with Atiprimod. A 3H-thymidine incorporation assay showed that Atiprimod not only inhibited the growth of the MCL cell lines SP53, MINO, Grant 519, and Jeko-1, but also freshly isolated patient MCL cells in a dose-dependent manner. Interestingly, Atiprimod also inhibited the proliferation of PHA-, PMA/ionomycin-, or anti-CD3 mAb/anti-CD28 mAb-activated, but not resting PBMCs from healthy donors. Flow cytometry analysis with fluorescence-labeled Annexin V and propidium iodide showed that Atiprimod induced apoptosis in both the cell lines and primary MCL cells in time-dependent and dose-dependent manners. Notably, Atiprimod did not induce apoptosis of normal T cells and B cells. Atiprimod was also effective and therapeutic in a MCL mouse model established in severe combined immunodeficient (SCID) mice. SP53 cells (5 × 106) were inoculated subcutaneously into the right leg of SCID mice. Three weeks later, after palpable tumors developed, mice were treated intraperitoneally with either vehicle alone (PBS) or Atiprimod (25 mg/kg per day) for 6 consecutive days. Tumor growth was significantly inhibited after Atiprimod treatment compared with vehicle control, and the survival time of tumor-bearing mice was significantly prolonged in the treatment group. Western blot analysis showed that apoptosis of MCL cells was induced through the activation of caspase-9, caspase-3, and PARP pathway. Furthermore, the expression of phosphorylated Bcl-2, Bax, Bad, Bax-xL, and cytochrome C was increased in Atiprimod-treated MCL cells. Pretreatment of cells with caspase-9 inhibitor (z-LEHD) or pan-caspase inhibitor (z-VAD) but not caspase-8 inhibitor (z-IETD) completely blocked Atiprimod-induced apoptosis. In conclusion, Atiprimod inhibits growth and induces apoptosis of MCL cells in vitro and in vivo. Cell apoptosis was induced via activation of the mitochondrial signaling pathway. The therapeutic efficacy of Atiprimod on MCL cells in the mouse model supports the use of Atiprimod as a potential agent in MCL chemotherapy.

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