-
Clinical Cancer Research. 04/2013;
-
[show abstract]
[hide abstract]
ABSTRACT: PURPOSE: The alkylating agent melphalan prolongs survival in multiple myeloma (MM) patients; however, it is associated with toxicities and development of drug-resistance. Here, we evaluated the efficacy of melphalan-flufenamide (Mel-flufen), a novel dipeptide prodrug of melphalan in MM. EXPERIMENTAL DESIGN: MM cell lines, primary patient cells, and the human MM xenograft animal model were utilized to study the antitumor activity of mel-flufen. RESULTS: Low doses of mel-flufen triggers a more rapid and higher intracellular concentrations of melphalan in MM cells than is achievable by free melphalan. Cytotoxicity analysis showed significantly lower IC50 of mel-flufen than melphalan in MM cells. Importantly, mel-flufen induces apoptosis even in melphalan-, and bortezomib-resistant MM cells. Mechanistic studies show that siRNA knockdown of aminopeptidase N, a key enzyme mediating intracellular conversion of mel-flufen to melphalan, attenuates anti-MM activity of mel-flufen. Furthermore, mel-flufen-induced apoptosis was associated with: 1) activation of caspases and PARP cleavage; 2) ROS generation; 3) mitochondrial dysfunction and release of cytochrome-c; and 4) induction of DNA damage. Moreover, mel-flufen inhibits MM cell migration and tumor-associated angiogenesis. Human MM xenograft studies showed a more potent inhibition of tumor growth in mice treated with mel-flufen than mice receiving equimolar doses of melphalan. Finally, combining mel-flufen with lenalidomide, bortezomib, or dexamethasone triggers synergistic anti-MM activity. CONCLUSIONS: Our preclinical study supports clinical evaluation of mel-flufen to enhance therapeutic potential of melphalan, overcome drug-resistance, and improve MM patient outcome.
Clinical Cancer Research 04/2013; · 7.74 Impact Factor
-
Clinical lymphoma, myeloma & leukemia 04/2013; 13(2):181-3.
-
[show abstract]
[hide abstract]
ABSTRACT: Multiple myeloma (MM) is the second most common hematologic malignancy affecting terminally differentiated plasma cells. Although high-dose chemotherapy and autologous stem cell transplantation improved survival in younger patients, the natural history of MM has been changed with the availability of five new agents approved in last 10 years (thalidomide, bortezomib, lenalidomide, liposomal doxorubicin and carfilzomib). Despite this significant improvement in overall outcome, MM remains incurable in majority of patients prompting continued search for additional therapeutic options. Extensive molecular and genomic characterization of MM cells in its bone marrow milieu, which affects myeloma cell growth and survival, has provided number of novel drugable targets and pathways. Perturbation of protein catabolism at multiple levels has become an important target in MM. Similarly with improvements in monoclonal antibody generation and vaccine development along with identification of number of cell surface and cellular targets have led to development of various strategies including antibodies and antibody-drug conjugates which are under investigation both preclinically as well as in early clinical studies. We propose that eventually, molecularly-informed multi-agent combination therapies will be required to eliminate the MM cell clone for a long-term disease control.
Clinical Cancer Research 03/2013; · 7.74 Impact Factor
-
Emanuela Leone,
Eugenio Morelli,
Maria T Di Martino,
Nicola Amodio,
Umberto Foresta,
Annamaria Gulla,
Marco Rossi,
Antonino Neri,
Antonio Giordano, Nikhil C Munshi,
Kenneth C Anderson,
Pierosandro Tagliaferri,
Pierfrancesco Tassone
[show abstract]
[hide abstract]
ABSTRACT: PURPOSE: Deregulated expression of microRNAs (miRNAs) plays a role in the pathogenesis and progression of multiple myeloma (MM). Among upregulated miRNAs, miR-21 has oncogenic potential and therefore represents an attractive target for the treatment of MM. Experimental design: Here, we investigated the in vitro and in vivo anti-MM activity of miR-21 inhibitors. RESULTS: Either transient enforced expression or lentivirus-based constitutive expression of miR-21 inhibitors triggered significant growth inhibition of patient MM or IL-6-dependent /independent MM cell lines and overcame the protective activity of human bone marrow stromal cells. Conversely, transfection of miR-21 significantly increased proliferation of MM cells, demonstrating its tumor promoting potential in MM. Importantly, upregulation of miR-21 canonical validated targets (PTEN, Rho-B and BTG2), together with functional impairment of both AKT and ERK signaling, were achieved by transfection of miR-21 inhibitors into MM cells. In vivo delivery of miR-21 inhibitors in SCID mice bearing human MM xenografts expressing miR-21 induced significant anti-tumor activity. Upregulation of PTEN and downregulation of p-AKT were observed in retrieved xenografts following treatment with miR-21 inhibitors. CONCLUSIONS: Our findings show the first evidence that in vivo antagonism of miR-21 exerts anti-MM activity, providing the rationale for clinical development of miR-21 inhibitors in this still incurable disease.
Clinical Cancer Research 02/2013; · 7.74 Impact Factor
-
Lian Xu,
Zachary R Hunter,
Guang Yang,
Yangsheng Zhou,
Yang Cao,
Xia Liu,
Enrica Morra,
Alessandra Trojani,
Antonino Greco,
Luca Arcaini,
Maria Varettoni,
Jennifer R Brown,
Yu-Tzu Tai,
Kenneth C Anderson, Nikhil C Munshi,
Christopher J Patterson,
Robert Manning,
Christina Tripsas,
Neal I Lindeman,
Steven P Treon
[show abstract]
[hide abstract]
ABSTRACT: By whole genome and/or Sanger sequencing, we recently identified a somatic mutation (MYD88 L265P) which stimulates NFκB activity, and is present >90% of Waldenstrom's Macroglobulinemia (WM) patients. MYD88 L265P was absent in 90% of IgM MGUS patients. We therefore developed conventional and real-time allele-specific (AS) PCR assays for more sensitive detection and quantification of MYD88 L265P. Using either assay, MYD88 L265P was detected in 97/104 (93%) WM and 13/24 (54%) IgM MGUS patients, and was either absent or rarely expressed in samples from splenic MZL (2/20; 10%), CLL (1/26; 4%), multiple myeloma (including IgM cases, 0/14), and IgG MGUS (0/9) patients, as well as healthy donors (0/40; p<1.5x10-5 for WM vs. other cohorts). Real-time AS-PCR identified IgM MGUS patients progressing to WM, and showed a high rate of concordance between MYD88 L265P ΔCT and bone marrow disease involvement (r=0.89, p=0.008) in WM patients undergoing treatment. These studies identify MYD88 L265P as a widely present mutation in WM and IgM MGUS patients using highly sensitive and specific AS-PCR assays with potential use in diagnostic discrimination and/or response assessment. The finding of this mutation in many IgM MGUS patients suggests that MYD88 L265P may be an early oncogenic event in WM pathogenesis.
Blood 01/2013; · 9.90 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Myeloid derived suppressor cells (MDSCs) are a heterogeneous, immature myeloid cell population with the ability to suppress immune responses. MDSCs have been characterized in infections, inflammatory diseases, and solid tumors; however, their presence and role in the tumor promoting, immune suppressive microenvironment in hematologic malignancies remains unclear. Here we assessed the presence, frequency, and functional characteristics of MDSCs in patients with newly diagnosed, relapsed and relapsed/refractory multiple myeloma (MM), compared to healthy donors. Additionally, we evaluated the immunomodulatory effects of lenalidomide and bortezomib on MDSCs in MM. CD11b(+)CD14(-)HLA-DR(-/low)CD33(+)CD15(+) MDSCs were significantly increased in both PB and BM of patients with active MM compared to healthy donors. Furthermore, MDSCs induced MM growth, while suppressing T cell mediated immune responses. Conversely, MM cells induced development of MDSCs from healthy donor PBMCs, confirming a bidirectional interaction between MDSCs and MM cells and immune effector cells. Our results further suggest that MDSCs may be associated with activity of disease in MM. Importantly, our studies suggest that inhibition of the tumor promoting and immune suppressive functions of MDSCs in MM may represent a promising novel immune-based therapeutic strategy.
Blood 01/2013; · 9.90 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The 90-kDa heat shock protein (Hsp90) has become an important therapeutic target with ongoing evaluation in a number of malignancies. Although Hsp90 inhibitors have a high therapeutic index with limited effects on normal cells, they have been described to inhibit dendritic cell function. However, its effect on human immune effector cells may have significant clinical implications, but remains unexplored. In this study, we have evaluated the effects of Hsp90 inhibition on human T lymphocyte and NK cells, including their Ag expression, activation, proliferation, and functional activities. These studies demonstrate that Hsp90 inhibition irreversibly downregulates cell surface expression of critical Ags (CD3, CD4, CD8), the costimulatory molecule (CD28, CD40L), and αβ receptors on T lymphocytes, as well as activating receptors (CD2, CD11a, CD94, NKp30, NKp44, NKp46, KARp50.3) on NK cells. Hsp90 inhibition significantly reduced CD4 protein expression on T lymphocytes at both the cell surface and intracellular level, which was shown to be associated with aberrant regulation of Src-kinase p56(Lck). Downregulation of the Ags triggered by Hsp90 inhibition on CD3(+) T lymphocytes, both in CD4(+) and CD8(+) T cell subsets, was associated with a disruption in their cellular activation, proliferation, and/or IFN-γ production, when the inhibition occurred either in activated or inactivated cells. In addition, downregulation of key activating receptors on NK cells following Hsp90 inhibition resulted in decreased cytotoxicity against tumor cells. Therefore, these observations demonstrate the need to closely monitor immune function in patients being treated with a Hsp90 inhibitor and may provide a potential therapeutic application in autoimmune diseases.
The Journal of Immunology 01/2013; · 5.79 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Genome-wide profiles of tumors obtained using functional genomics platforms are being deposited to the public repositories at an astronomical scale, as a result of focused efforts by individual laboratories and large projects such as the Cancer Genome Atlas (TCGA) and the International Cancer Genome Consortium. Consequently, there is an urgent need for reliable tools that integrate and interpret these data in light of current knowledge and disseminate results to biomedical researchers in a user-friendly manner. We have built the canEvolve web portal to meet this need.
canEvolve query functionalities are designed to fulfill most frequent analysis needs of cancer researchers with a view to generate novel hypotheses. canEvolve stores gene, microRNA (miRNA) and protein expression profiles, copy number alterations for multiple cancer types, and protein-protein interaction information. canEvolve allows querying of results of primary analysis, integrative analysis and network analysis of oncogenomics data. The querying for primary analysis includes differential gene and miRNA expression as well as changes in gene copy number measured with SNP microarrays. canEvolve provides results of integrative analysis of gene expression profiles with copy number alterations and with miRNA profiles as well as generalized integrative analysis using gene set enrichment analysis. The network analysis capability includes storage and visualization of gene co-expression, inferred gene regulatory networks and protein-protein interaction information. Finally, canEvolve provides correlations between gene expression and clinical outcomes in terms of univariate survival analysis.
At present canEvolve provides different types of information extracted from 90 cancer genomics studies comprising of more than 10,000 patients. The presence of multiple data types, novel integrative analysis for identifying regulators of oncogenesis, network analysis and ability to query gene lists/pathways are distinctive features of canEvolve. canEvolve will facilitate integrative and meta-analysis of oncogenomics datasets.
The canEvolve web portal is available at http://www.canevolve.org/.
PLoS ONE 01/2013; 8(2):e56228. · 4.09 Impact Factor
-
Yingxiang Li,
Xujun Wang,
Haiyang Zheng,
Chengyang Wang,
Stéphane Minvielle,
Florence Magrangeas,
Hervé Avet-Loiseau,
Parantu K Shah,
Yong Zhang, Nikhil C Munshi,
Cheng Li
[show abstract]
[hide abstract]
ABSTRACT: Multiple myeloma (MM) is a cancer of antibody-making plasma cells. It frequently harbors alterations in DNA and chromosome copy numbers, and can be divided into two major subtypes, hyperdiploid (HMM) and non-hyperdiploid multiple myeloma (NHMM). The two subtypes have different survival prognosis, possibly due to different but converging paths to oncogenesis. Existing methods for identifying the two subtypes are fluorescence in situ hybridization (FISH) and copy number microarrays, with increased cost and sample requirements. We hypothesize that chromosome alterations have their imprint in gene expression through dosage effect. Using five MM expression datasets that have HMM status measured by FISH and copy number microarrays, we have developed and validated a K-nearest-neighbor method to classify MM into HMM and NHMM based on gene expression profiles. Classification accuracy for test datasets ranges from 0.83 to 0.88. This classification will enable researchers to study differences and commonalities of the two MM subtypes in disease biology and prognosis using expression datasets without need for additional subtype measurements. Our study also supports the advantages of using cancer specific characteristics in feature design and pooling multiple rounds of classification results to improve accuracy. We provide R source code and processed datasets at www.ChengLiLab.org/software.
PLoS ONE 01/2013; 8(3):e58809. · 4.09 Impact Factor
-
Paul G Richardson,
David Siegel,
Rachid Baz,
Susan L Kelley, Nikhil C Munshi,
Jacob Laubach,
Daniel Sullivan,
Melissa Alsina,
Robert Schlossman,
Irene M Ghobrial, [......],
Laura McBride,
Elizabeth Bilotti,
Palka Anand,
Lisa Nardelli,
Sandra Wear,
Gail Larkins,
Min Chen,
Mohamad Zaki,
Christian Jacques,
Kenneth C Anderson
[show abstract]
[hide abstract]
ABSTRACT: This phase 1 dose-escalation study determined the maximum tolerated dose (MTD) of oral pomalidomide (4 dose levels) administered on days 1 to 21 of each 28-day cycle in patients with relapsed and refractory multiple myeloma (RRMM). After 4 cycles, patients who progressed or had not achieved minimal response (serum and urine M-protein reduction of ≥ 25% and ≥ 50%) could receive dexamethasone, 40 mg/week. Safety and efficacy were evaluated. Thirty-eight patients who had received both bortezomib and lenalidomide (median 6 prior therapies) were enrolled; 63% were refractory to both lenalidomide and bortezomib. There were 4 dose-limiting toxicities (grade 4 neutropenia) at 5 mg/day so the MTD was 4 mg/day. Peripheral neuropathy and venous thromboembolism rates were low (≤ 5%). Among the 38 patients enrolled (including 22 with added dexamethasone), 42% achieved minimal response or better, 21% partial response or better, and 3% complete response. Median duration of response, progression-free survival, and overall survival were 4.6, 4.6, and 18.3 months, respectively. Pomalidomide 4 mg/day on days 1 to 21 of each 28-day cycle, with or without dexamethasone (40 mg/week), has encouraging activity with manageable toxicity in RRMM, including those refractory to both lenalidomide and bortezomib. Study registered at http://www.clinicaltrials.gov as NCT00833833.
Blood 12/2012; · 9.90 Impact Factor
-
Roger G Owen,
Robert A Kyle,
Marvin J Stone,
Andy C Rawstron,
Veronique Leblond,
Giampaolo Merlini,
Ramon Garcia-Sanz,
Enrique M Ocio,
Enrica Morra,
Pierre Morel, [......],
Douglas E Joshua,
Efstathios Kastritis,
Evangelos Terpos,
Irene M Ghobrial,
Xavier Leleu,
Morie A Gertz,
Stephen M Ansell,
William G Morice,
Eva Kimby,
Steven P Treon
[show abstract]
[hide abstract]
ABSTRACT: This report represents a further update of the consensus panel criteria for the assessment of clinical response in patients with Waldenström macroglobulinaemia (WM). These criteria have been updated in light of further data demonstrating an improvement in categorical responses with new drug regimens as well as acknowledgement of the fact that such responses are predictive of overall outcome. A number of key changes are proposed but challenges do however remain and these include the variability in kinetics of immunoglobulin M (IgM) reduction with different treatment modalities and the apparent discrepancy between IgM and bone marrow/tissue response noted with some regimens. Planned sequential bone marrow assessments are encouraged in clinical trials.
British Journal of Haematology 11/2012; · 4.94 Impact Factor
-
Maria T Di Martino,
Emanuela Leone,
Nicola Amodio,
Umberto Foresta,
Marta Lionetti,
Maria Rita Pitari,
Maria E Gallo Cantafio,
Annamaria Gullà,
Francesco Conforti,
Eugenio Morelli, [......],
Marco Rossi,
Massimo Negrini,
Manlio Ferrarini,
Michele Caraglia,
Masood A Shammas, Nikhil C Munshi,
Kenneth C Anderson,
Antonino Neri,
Pierosandro Tagliaferri,
Pierfrancesco Tassone
[show abstract]
[hide abstract]
ABSTRACT: PURPOSE: Deregulated expression of microRNAs (miRNAs) has been demonstrated in multiple myeloma (MM). A promising strategy to achieve a therapeutic effect by targeting the miRNA regulatory network is to enforce the expression of miRNAs that act as tumor suppressor genes, such as miR-34a EXPERIMENTAL DESIGN: Here, we investigated the therapeutic potential of synthetic miR-34a against human MM cells in vitro and in vivo RESULTS: Either transient expression of miR-34a synthetic mimics or lentivirus-based stable enforced expression of miR-34a gene triggered growth inhibition and apoptosis in MM cells in vitro. Synthetic miR-34a downregulated canonic targets BCL2, CDK6 and NOTCH1 at both the mRNA and protein level. Lentiviral vector-transduced MM xenografts with constitutive miR-34a expression showed high growth inhibition in SCID mice. The anti-MM activity of lipidic-formulated miR-34a was further demonstrated in vivo in two different experimental settings: i) SCID mice bearing non transduced MM xenografts; and ii) SCID-synth-hu mice implanted with synthetic 3D scaffolds reconstituted with human bone marrow stromal cells and then engrafted with human MM cells. Relevant tumor growth inhibition and survival improvement were observed in mice bearing TP53-mutated MM xenografts treated with miR-34a mimics in the absence of systemic toxicity CONCLUSIONS: Our findings provide a proof-of-principle that formulated synthetic miR-34a has therapeutic activity in preclinical models and support a framework for development of miR-34a-based treatment strategies in MM patients.
Clinical Cancer Research 10/2012; · 7.74 Impact Factor
-
Kohichi Takada,
Di Zhu,
Gregory H Bird,
Kumar Sukhdeo,
Jian-Jun Zhao,
Mala Mani,
Madeleine Lemieux,
Daniel E Carrasco,
Jeremy Ryan,
David Horst,
Mariateresa Fulciniti, Nikhil C Munshi,
Wenqing Xu,
Andrew L Kung,
Ramesh A Shivdasani,
Loren D Walensky,
Daniel Ruben Carrasco
[show abstract]
[hide abstract]
ABSTRACT: Deregulated Wnt/β-catenin signaling underlies the pathogenesis of a broad range of human cancers, yet the development of targeted therapies to disrupt the resulting aberrant transcription has proved difficult because the pathway comprises large protein interaction surfaces and regulates many homeostatic functions. Therefore, we have directed our efforts toward blocking the interaction of β-catenin with B cell lymphoma 9 (BCL9), a co-activator for β-catenin-mediated transcription that is highly expressed in tumors but not in the cells of origin. BCL9 drives β-catenin signaling through direct binding mediated by its α-helical homology domain 2. We developed a stabilized α helix of BCL9 (SAH-BCL9), which we show targets β-catenin, dissociates native β-catenin/BCL9 complexes, selectively suppresses Wnt transcription, and exhibits mechanism-based antitumor effects. SAH-BCL9 also suppresses tumor growth, angiogenesis, invasion, and metastasis in mouse xenograft models of Colo320 colorectal carcinoma and INA-6 multiple myeloma. By inhibiting the BCL9-β-catenin interaction and selectively suppressing oncogenic Wnt transcription, SAH-BCL9 may serve as a prototype therapeutic agent for cancers driven by deregulated Wnt signaling.
Science translational medicine 08/2012; 4(148):148ra117. · 7.80 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Condensation of Igs has been observed in pharmaceutical formulations and in vivo in cases of cryoglobulinemia. We report a study of monoclonal IgG cryoglobulins overexpressed by two patients with multiple myeloma. These cryoglobulins form crystals, and we measured their solubility lines. Depending on the supersaturation, we observed a variety of condensate morphologies consistent with those reported in clinical investigations. Remarkably, the crystallization can occur at quite low concentrations. This suggests that, even within the regular immune response to infections, cryoprecipitation of Ig can be possible.
Proceedings of the National Academy of Sciences 07/2012; 109(33):13359-61. · 9.68 Impact Factor
-
Simona Blotta,
Jana Jakubikova,
Teresa Calimeri,
Aldo M Roccaro,
Nicola Amodio,
Abdel Kareem Azab,
Umberto Foresta,
Constantine S Mitsiades,
Marco Rossi,
Katia Todoerti,
Stefano Molica,
Fortunato Morabito,
Antonino Neri,
Piersandro Tagliaferri,
Pierfrancesco Tassone,
Kenneth C Anderson, Nikhil C Munshi
[show abstract]
[hide abstract]
ABSTRACT: The Hedgehog (Hh)-pathway is required for cell-fate determination during the embryonic life, as well as cell growth and differentiation in the adult organism, where the inappropriate activation has been implicated in several cancers. Here, we demonstrate that Hh-signaling plays a significant role in growth and survival of multiple myeloma (MM) cells. We observed that CD138(+) MM cells express Hh-genes and confirmed Smoothened (Smo)-dependent Hh-signaling in MM using a novel synthetic Smo-inhibitor, NVP-LDE225 (Novartis), which decreased MM cell viability by inducing specific down-regulation of Gli1 and Ptch1, hallmarks of Hh-activity. Additionally, we detected a nuclear localization of Gli1 in MM cells, which is completely abrogated by Forskolin, a Gli1 modulating compound, confirming Smo-independent mechanisms leading to Hh-activation in MM. Finally, we identified that bone-marrow stromal cells (BMSCs) are a source of Shh-ligand, although they are resistant to Hh-inhibitor due to defective Smo expression and Ptch1 up-regulation. Further in vitro as well as in vivo studies showed anti-tumor efficacy of NVP-LDE225 in combination with Bortezomib. All together, our data demonstrate activation of both canonical and non canonical Hh-pathway in MM, thus providing the rationale for testing Hh-inhibitors in clinical trials, in order to improve MM patient outcome.
Blood 07/2012; · 9.90 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The efficacy of peptide vaccines may be enhanced by stimulating immune cells with multiple peptides derived from distinct tumor-associated antigens. We have evaluated the heteroclitic XBP1-US(184-192) (YISPWILAV), heteroclitic XBP1-SP(367-375) (YLFPQLISV), native CD138(260-268) (GLVGLIFAV), and native CS1(239-247) (SLFVLGLFL) peptides, which have strong HLA-A2 affinity and immunogenicity in combination, for their ability to elicit multiple myeloma antigen-specific responses.
Multipeptide-specific cytotoxic T lymphocytes (MP-CTL) were generated by the stimulation of CD3(+) T lymphocytes from HLA-A2(+) individuals with either autologous mature dendritic cells or T2 cells pulsed with a cocktail of these four peptides.
The peptide cocktail did not compromise tumor antigen-specific activity of CTLs. MP-CTLs displayed increased total, effector memory (CCR7(-)CD45RO(+)), and activated (CD69(+)) CD3(+)CD8(+) T lymphocytes. In addition, MP-CTL showed IFN-γ production, cell proliferation, and cytotoxicity against HLA-A2(+) multiple myeloma cells, including cells of HLA-A2(+) patients with multiple myeloma. Importantly, MP-CTLs showed specific responses in functional assays to each relevant peptide but not to an irrelevant HLA-A2-specific CMV pp65 (NLVPMVATV) peptide.
These results highlight the potential therapeutic application of vaccination with a cocktail of HLA-A2-specific peptides to induce CTLs with a broad spectrum of immune responses against multiple myeloma antigens.
Clinical Cancer Research 07/2012; 18(17):4850-60. · 7.74 Impact Factor
-
Yu-Tzu Tai,
Betty Y Chang,
Sun-Young Kong,
Mariateresa Fulciniti,
Guang Yang,
Yolanda Calle,
Yiguo Hu,
Jianhong Lin,
Jian-Jun Zhao,
Antonia Cagnetta, [......],
Qiuju Wang,
Chirag Acharya,
Daniel R Carrasco,
Joseph J Buggy,
Laurence Elias,
Steven P Treon,
William Matsui,
Paul Richardson, Nikhil C Munshi,
Kenneth C Anderson
[show abstract]
[hide abstract]
ABSTRACT: Bruton tyrosine kinase (Btk) has a well-defined role in B-cell development, whereas its expression in osteoclasts (OCs) further suggests a role in osteoclastogenesis. Here we investigated effects of PCI-32765, an oral and selective Btk inhibitor, on osteoclastogenesis as well as on multiple myeloma (MM) growth within the BM microenvironment. PCI-32765 blocked RANKL/M-CSF-induced phosphorylation of Btk and downstream PLC-γ2 in OCs, resulting in diminished TRAP5b (ED50 = 17 nM) and bone resorption activity. PCI-32765 also inhibited secretion of multiple cytokines and chemokines from OC and BM stromal cell cultures from both normal donors (ED50 = 0.5 nM) and MM patients. It decreased SDF-1-induced migration of MM cells, and down-regulated MIP1-α/CCL3 in MM cells. It also blocked MM cell growth and survival triggered by IL-6 or coculture with BM stromal cells or OCs in vitro. Importantly, PCI-32765 treatment significantly inhibits in vivo MM cell growth (P < .03) and MM cell-induced osteolysis of implanted human bone chips in SCID mice. Moreover, PCI-32765 prevents in vitro colony formation by stem-like cells from MM patients. Together, these results delineate functional sequelae of Btk activation mediating osteolysis and growth of MM cells, supporting evaluation of PCI-32765 as a novel therapeutic in MM.
Blood 06/2012; 120(9):1877-87. · 9.90 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The CS1 antigen provides a unique target for the development of an immunotherapeutic strategy to treat patients with multiple myeloma (MM). This study aimed to identify HLA-A2(+) immunogenic peptides from the CS1 antigen, which induce peptide-specific cytotoxic T lymphocytes (CTL) against HLA-A2(+) MM cells. We identified a novel immunogenic HLA-A2-specific CS1(239-247) (SLFVLGLFL) peptide, which induced CS1-specific CTL (CS1-CTL) to MM cells. The CS1-CTL showed a distinct phenotype, with an increased percentage of effector memory and activated CTL and a decreased percentage of naïve CTL. CS1(239-247) peptide-specific CD8(+) T cells were detected by DimerX analyses and demonstrated functional activities specific to the peptide. The CTL displayed HLA-A2-restricted and antigen-specific cytotoxicity, proliferation, degranulation and γ-interferon (IFN-γ) production against both primary MM cells and MM cell lines. In addition, the effector memory cells subset (CD45RO(+) CCR7(-) /CD3(+) CD8(+) ) within CS1-CTL showed a higher level of CD107a degranulation and IFN-γ production as compared to effector cells (CD45RO(-) CCR7(-) /CD3(+) CD8(+) ) against HLA-A2(+) primary MM cells or MM cell lines. In conclusion, this study introduced a novel immunogenic HLA-A2-specific CS1(239-247) peptide capable of inducing antigen-specific CTL against MM cells that will provide a framework for its application as a novel MM immunotherapy.
British Journal of Haematology 04/2012; 157(6):687-701. · 4.94 Impact Factor
-
Naoya Mimura,
Mariateresa Fulciniti,
Gullu Gorgun,
Yu-Tzu Tai,
Diana Cirstea,
Loredana Santo,
Yiguo Hu,
Claire Fabre,
Jiro Minami,
Hiroto Ohguchi, [......],
Victor Tam,
Nathalie L Kertesz,
Uriel M Malyankar,
Mark Hokenson,
Tuan Pham,
Qingping Zeng,
John B Patterson,
Paul G Richardson, Nikhil C Munshi,
Kenneth C Anderson
[show abstract]
[hide abstract]
ABSTRACT: Multiple myeloma (MM) cells are characterized by high protein synthesis resulting in chronic endoplasmic reticulum (ER) stress, which is adaptively managed by the unfolded protein response. Inositol-requiring enzyme 1α (IRE1α) is activated to splice X-box binding protein 1 (XBP1) mRNA, thereby increasing XBP1s protein, which in turn regulates genes responsible for protein folding and degradation during the unfolded protein response. In this study, we examined whether IRE1α-XBP1 pathway is a potential therapeutic target in MM using a small-molecule IRE1α endoribonuclease domain inhibitor MKC-3946. MKC-3946 triggered modest growth inhibition in MM cell lines, without toxicity in normal mononuclear cells. Importantly, it significantly enhanced cytotoxicity induced by bortezomib or 17-AAG, even in the presence of bone marrow stromal cells or exogenous IL-6. Both bortezomib and 17-AAG induced ER stress, evidenced by induction of XBP1s, which was blocked by MKC-3946. Apoptosis induced by these agents was enhanced by MKC-3946, associated with increased CHOP. Finally, MKC-3946 inhibited XBP1 splicing in a model of ER stress in vivo, associated with significant growth inhibition of MM cells. Taken together, our results demonstrate that blockade of XBP1 splicing by inhibition of IRE1α endoribonuclease domain is a potential therapeutic option in MM.
Blood 04/2012; 119(24):5772-81. · 9.90 Impact Factor
