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Abstract
In recent years considerable progress has been made in the treatment of patients with B-cell non-Hodgkin lymphoma (NHL). Although responses can be achieved with combination chemotherapy regimens, a substantial proportion of patients are still not cured. In recent years, the knowledge of the cellular and molecular biology of distinct types of B-cell NHL have led to the development of a new class of drugs that specifically targets unique disease-specific pathways. This review will focus on novel therapies that are being developed for the treatment of B-cell NHL including those targeting the B-cell receptor signaling pathway, the proteasome, epigenetic lesions, novel anti-apoptotic drugs, new monoclonal antibodies and immunomodulatory drugs.
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Affiliation(s)
- Javier Briones
- Hematology Service, Hospital Santa Creu i Sant Pau, Mas Casanovas 90, 4th floor, Room 2, 08040 Barcelona, Spain.
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152
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Recruitment of PKC-betaII to lipid rafts mediates apoptosis-resistance in chronic lymphocytic leukemia expressing ZAP-70. Leukemia 2009; 24:141-52. [PMID: 19907441 DOI: 10.1038/leu.2009.216] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
ZAP-70 is a key signaling molecule in T cells. It couples the antigen-activated T-cell receptor to downstream signaling pathways. Its expression in leukemic B-cells derived from a subgroup of patients with chronic lymphocytic leukemia (CLL) is associated with an aggressive course of the disease. However, its implication for the pathogenesis of aggressive CLL is still unclear. In this study, we show that the expression of ZAP-70 enhances the signals associated with the B-cell receptor, recruiting protein kinase C-betaII (PKC-betaII) into lipid raft domains. Subsequently, PKC-betaII is activated and shuttles from the plasma membrane to the mitochondria. We unravel that the antiapoptotic protein Bcl-2 and its antagonistic BH3-protein Bim(EL) are putative substrates for PKC-betaII. PKC-betaII-mediated phosphorylation of Bcl-2 augments its antiapoptotic function by increasing its ability to sequester more pro-apoptotic Bim(EL.) In addition, the phosphorylation of Bim(EL) by PKC-betaII leads to its proteasomal degradation. These changes confer leukemic cells to a more antiapoptotic state with aggressiveness of the disease. Most importantly, these molecular changes can be therapeutically targeted with the small molecule inhibitor Enzastaurin. We provide evidence that this compound is highly active in leukemic cells and augments the cytotoxic effects of standard chemotherapeutic drugs.
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153
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Willey CD, Xiao D, Tu T, Kim KW, Moretti L, Niermann KJ, Tawtawy MN, Quarles CC, Lu B. Enzastaurin (LY317615), a protein kinase C beta selective inhibitor, enhances antiangiogenic effect of radiation. Int J Radiat Oncol Biol Phys 2009; 77:1518-26. [PMID: 19906497 DOI: 10.1016/j.ijrobp.2009.06.044] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2008] [Revised: 06/23/2009] [Accepted: 06/24/2009] [Indexed: 02/03/2023]
Abstract
PURPOSE Angiogenesis has generated interest in oncology because of its important role in cancer growth and progression, particularly when combined with cytotoxic therapies, such as radiotherapy. Among the numerous pathways influencing vascular growth and stability, inhibition of protein kinase B(Akt) or protein kinase C(PKC) can influence tumor blood vessels within tumor microvasculature. Therefore, we wanted to determine whether PKC inhibition could sensitize lung tumors to radiation. METHODS AND MATERIALS The combination of the selective PKCbeta inhibitor Enzastaurin (ENZ, LY317615) and ionizing radiation were used in cell culture and a mouse model of lung cancer. Lung cancer cell lines and human umbilical vascular endothelial cells (HUVEC) were examined using immunoblotting, cytotoxic assays including cell proliferation and clonogenic assays, and Matrigel endothelial tubule formation. In vivo, H460 lung cancer xenografts were examined for tumor vasculature and proliferation using immunohistochemistry. RESULTS ENZ effectively radiosensitizes HUVEC within in vitro models. Furthermore, concurrent ENZ treatment of lung cancer xenografts enhanced radiation-induced destruction of tumor vasculature and proliferation by IHC. However, tumor growth delay was not enhanced with combination treatment compared with either treatment alone. Analysis of downstream effectors revealed that HUVEC and the lung cancer cell lines differed in their response to ENZ and radiation such that only HUVEC demonstrate phosphorylated S6 suppression, which is downstream of mTOR. When ENZ was combined with the mTOR inhibitor, rapamycin, in H460 lung cancer cells, radiosensitization was observed. CONCLUSION PKC appears to be crucial for angiogenesis, and its inhibition by ENZ has potential to enhance radiotherapy in vivo.
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Affiliation(s)
- Christopher D Willey
- Vanderbilt Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
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154
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Meng XW, Heldebrant MP, Flatten KS, Loegering DA, Dai H, Schneider PA, Gomez TS, Peterson KL, Trushin SA, Hess AD, Smith BD, Karp JE, Billadeau DD, Kaufmann SH. Protein kinase Cbeta modulates ligand-induced cell surface death receptor accumulation: a mechanistic basis for enzastaurin-death ligand synergy. J Biol Chem 2009; 285:888-902. [PMID: 19887445 DOI: 10.1074/jbc.m109.057638] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Although treatment with the protein kinase C (PKC) activator phorbol 12-myristate 13-acetate (PMA) is known to protect a subset of cells from induction of apoptosis by death ligands such as Fas ligand and tumor necrosis factor-alpha-related apoptosis-inducing ligand, the mechanism of this protection is unknown. This study demonstrated that protection in short term apoptosis assays and long term proliferation assays was maximal when Jurkat or HL-60 human leukemia cells were treated with 2-5 nm PMA. Immunoblotting demonstrated that multiple PKC isoforms, including PKCalpha, PKCbeta, PKCepsilon, and PKC, translocated from the cytosol to a membrane-bound fraction at these PMA concentrations. When the ability of short hairpin RNA (shRNA) constructs that specifically down-regulated each of these isoforms was examined, PKCbeta shRNA uniquely reversed PMA-induced protection against cell death. The PKCbeta-selective small molecule inhibitor enzastaurin had a similar effect. Although mass spectrometry suggested that Fas is phosphorylated on a number of serines and threonines, mutation of these sites individually or collectively had no effect on Fas-mediated death signaling or PMA protection. Further experiments demonstrated that PMA diminished ligand-induced cell surface accumulation of Fas and DR5, and PKCbeta shRNA or enzastaurin reversed this effect. Moreover, enzastaurin sensitized a variety of human tumor cell lines and clinical acute myelogenous leukemia isolates, which express abundant PKCbeta, to tumor necrosis factor-alpha related apoptosis-inducing ligand-induced death in the absence of PMA. Collectively, these results identify a specific PKC isoform that modulates death receptor-mediated cytotoxicity as well as a small molecule inhibitor that mitigates the inhibitory effects of PKC activation on ligand-induced death receptor trafficking and cell death.
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Affiliation(s)
- Xue Wei Meng
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, Minnesota 55905, USA
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155
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Mounier N, Katlama C, Costagliola D, Chichmanian RM, Spano JP. Drug interactions between antineoplastic and antiretroviral therapies: Implications and management for clinical practice. Crit Rev Oncol Hematol 2009; 72:10-20. [DOI: 10.1016/j.critrevonc.2008.10.013] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2008] [Revised: 10/07/2008] [Accepted: 10/17/2008] [Indexed: 11/25/2022] Open
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156
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Hanauske AR, Lahn M, Musib L, Weigang-Köhler K, Yilmaz E, Graefe T, Kuenen B, Thornton D, McNealy P, Giaccone G. Phase Ib safety and pharmacokinetic evaluation of daily and twice daily oral enzastaurin in combination with pemetrexed in advanced/metastatic cancer. Ann Oncol 2009; 20:1565-1575. [DOI: 10.1093/annonc/mdp049] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
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157
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Jian W, Yamashita H, Levitt JM, Lerner SP, Sonpavde G. Enzastaurin shows preclinical antitumor activity against human transitional cell carcinoma and enhances the activity of gemcitabine. Mol Cancer Ther 2009; 8:1772-8. [PMID: 19509273 DOI: 10.1158/1535-7163.mct-09-0141] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Enzastaurin, an oral serine/threonine kinase inhibitor, suppresses signaling through protein kinase C (PKC)-beta and the phosphatidylinositol 3-kinase/AKT pathways. We preclinically evaluated enzastaurin alone and in combination with gemcitabine for transitional cell cancer (TCC). Immunohistochemistry (IHC) was done on 105 human samples from a microarray to show the expression of PKC-beta. The preclinical antitumor activity of enzastaurin and gemcitabine as single agents and in combination against aggressive human -lines (-SUP and 5637) and murine subcutaneous xenografts bearing 5637 cells was determined. Western Blot was done on tumor cells in vitro to detect signaling through PKC-beta, GSK-3beta, and AKT. The effect on cell migration was determined in vitro. Modulation of proliferation (Ki-67), apoptosis (cleaved caspase-3), and angiogenesis (CD31) in vivo was determined by IHC. IHC done on human TCC samples from a microarray showed the expression of PKC-beta in 33% of tumors. Enzastaurin induced significant apoptosis and inhibited proliferation in vitro at low micromolar concentrations. The in vitro inhibitory activity of combination enzastaurin and gemcitabine by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay seemed synergistic. Western Blotting revealed down-regulation of Akt, PKC-beta, and GSK-3 beta phosphorylation. Enzastaurin inhibited migration at an earlier time point independent of antiproliferative activity. Combination therapy had significantly superior antitumor activity in murine xenografts compared with untreated controls, whereas single agents did not. IHC showed reduced Ki-67 and CD31 and increased cleaved caspase-3 with combination therapy compared with controls. Enzastaurin showed preclinical antitumor activity against human TCC and enhanced the activity of gemcitabine.
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Affiliation(s)
- Weiguo Jian
- Scott Department of Urology, Baylor College of Medicine, Houston, TX, USA
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158
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Delmonte A, Ghielmini M, Sessa C. Beyond monoclonal antibodies: new therapeutic agents in non-Hodgkin's lymphomas. Oncologist 2009; 14:511-25. [PMID: 19411316 DOI: 10.1634/theoncologist.2008-0214] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The availability of active monoclonal antibodies, either as single agents or in combination with cytotoxic agents, has improved treatment results in non-Hodgkin's lymphoma (NHL). Despite this and the increasing number of available active monoclonal antibodies, alone or conjugated with radioisotopes, not all types of lymphoma are sensitive to these biological agents and often they become resistant because of different molecular mechanisms. New molecular targets in neoplastic cells are emerging and provide the rationale for novel discovery initiatives. In fact, a greater knowledge of the biology of lymphoma and the identification of compounds selectively active against a potential therapeutic pathway have already improved the time to progression and survival time of patients with some subtypes of NHL. The growing list of new drugs provides the exciting prospect of developing disease-specific and even patient-specific therapies. The aim of this review is to identify and discuss non-monoclonal antibody new therapeutic agents in terms of mechanism of action and clinical results. The preclinical and clinical features of proteasome inhibitors, histone deacetylase inhibitors, thalidomide and lenalidomide, mammalian target of rapamycin inhibitors, antisense oligonucleotides, heat shock protein inhibitors, protein kinase C inhibitors, antiangiogenic agents, and new cytotoxics are reviewed.
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Affiliation(s)
- Angelo Delmonte
- Oncology Institute of Southern Switzerland, Ospedale S. Giovanni, 6500 Bellinzona, Switzerland.
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159
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Fields AP, Calcagno SR, Krishna M, Rak S, Leitges M, Murray NR. Protein kinase Cbeta is an effective target for chemoprevention of colon cancer. Cancer Res 2009; 69:1643-50. [PMID: 19221092 DOI: 10.1158/0008-5472.can-08-3187] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Colon cancer develops over a period of 10 to 15 years, providing a window of opportunity for chemoprevention and early intervention. However, few molecular targets for effective colon cancer chemoprevention have been characterized and validated. Protein kinase CbetaII (PKCbetaII) plays a requisite role in the initiation of colon carcinogenesis in a preclinical mouse model by promoting proliferation and increased beta-catenin accumulation. In this study, we test the hypothesis that PKCbetaII is an effective target for colon cancer chemoprevention using enzastaurin (LY317615), a PKCbeta-selective inhibitor, in a mouse model of colon carcinogenesis. We find that enzastaurin potently reduces azoxymethane-induced colon tumor initiation and progression by inhibiting PKCbetaII-mediated tumor cell proliferation and beta-catenin accumulation. Biochemically, enzastaurin reduces expression of the PKCbetaII- and beta-catenin/T-cell factor-regulated genes PKCbetaII, cyclooxygenase II, and vascular endothelial growth factor, three genes implicated in colon carcinogenesis. Our results show that enzastaurin is an effective chemopreventive agent in a mouse model of sporadic colon cancer that significantly reduces both tumor initiation and progression by inhibiting expression of proproliferative genes. Thus, PKCbetaII is an important target for colon cancer chemoprevention and the PKCbeta-selective inhibitor enzastaurin may represent an effective chemopreventive agent in patients at high risk for colon cancer.
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Affiliation(s)
- Alan P Fields
- Departments of Cancer Biology and Pathology, Mayo Clinic College of Medicine, Jacksonville, Florida 32224, USA
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160
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Murray NR, Weems J, Braun U, Leitges M, Fields AP. Protein kinase C betaII and PKCiota/lambda: collaborating partners in colon cancer promotion and progression. Cancer Res 2009; 69:656-62. [PMID: 19147581 DOI: 10.1158/0008-5472.can-08-3001] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We previously showed that elevated expression of either protein kinase CbetaII (PKCbetaII) or PKCiota/lambda enhances colon carcinogenesis in mice. Here, we use novel bitransgenic mice to determine the relative importance of PKCbetaII and PKCiota/lambda in colon carcinogenesis in two complimentary models of colon cancer in vivo. Bitransgenic mice overexpressing PKCbetaII and constitutively active PKCiota (PKCbetaII/caPKCiota) or kinase-deficient, dominant-negative PKCiota (PKCbetaII/kdPKCiota) in the colon exhibit a similar increase in colon tumor incidence, tumor size, and tumor burden in response to azoxymethane (AOM) when compared with nontransgenic littermates. However, PKCbetaII/kdPKCiota mice develop predominantly benign colonic adenomas, whereas PKCbetaII/caPKCiota mice develop malignant carcinomas. In contrast, PKCbeta-deficient (PKCbeta(-/-)) mice fail to develop tumors even in the presence of caPKCiota. Our previous data indicated that PKCbetaII drives tumorigenesis and proliferation by activating beta-catenin/Apc signaling. Consistent with this conclusion, genetic deletion of PKCbeta has no effect on spontaneous tumorigenesis in Apc(min/+) mice. In contrast, tissue-specific knockout of PKClambda significantly suppresses intestinal tumor formation in Apc(min/+) mice. Our data show that PKCbetaII and PKCiota/lambda serve distinct, nonoverlapping functions in colon carcinogenesis. PKCbetaII is required for AOM-induced tumorigenesis but is dispensable for tumor formation in Apc(Min/+) mice. PKCiota/lambda promotes tumor progression in both AOM- and Apc(min/+)-induced tumorigenesis. Thus, PKCbetaII and PKCiota, whose expression is elevated in both rodent and human colon tumors, collaborate to drive colon tumor formation and progression, respectively.
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Affiliation(s)
- Nicole R Murray
- Department of Cancer Biology, Mayo Clinic College of Medicine, Jacksonville, Florida 32224, USA
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161
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A phase II study of oral enzastaurin in patients with metastatic breast cancer previously treated with an anthracycline and a taxane containing regimen. Invest New Drugs 2009; 27:565-70. [PMID: 19214387 DOI: 10.1007/s10637-009-9220-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2008] [Accepted: 01/13/2009] [Indexed: 10/21/2022]
Abstract
PURPOSE Enzastaurin is a potent, serine-threonine kinase inhibitor which selectively targets PKCβ and PI3K/AKT signaling pathways to reduce cell proliferation, induce apoptosis, and inhibit angiogenesis. As PKCbeta and PI3K/AKT signaling are both involved in breast cancer pathogenesis, this phase II study evaluated the efficacy and toxicity of enzastaurin in previously treated patients with metastatic breast cancer (MBC). PATIENTS AND METHODS Eligible patients had histologically confirmed MBC with measurable disease, and must have received prior anthracycline and taxane chemotherapy, but not more than two prior regimens for MBC. Human epidermal growth factor 2 (HER2)-positive patients must have progressed on prior trastuzumab therapy. Enzastaurin, 1,125-mg loading dose on day 1 followed by 500 mg daily, was administered orally in 28-day cycles. Response was assessed every 2 cycles according to the Response Evaluation Criteria in Solid Tumors (RECIST) criteria. RESULTS Twenty-one patients enrolled between November 2006 and September 2007. Fourteen (66.7%) patients completed at least two cycles of therapy. No patients developed Grade 3/4 hematologic toxicity. Grade 3 nonhematologic toxicity was rare (<5%) and most commonly attributed to MBC progression. There were no objective responses and no patients with stable disease for >/=6 months. Median progression-free survival was 1.68 months (95%CI: 1.02, 1.74). CONCLUSIONS Enzastaurin monotherapy was well tolerated, but demonstrated no activity in patients with heavily pretreated MBC.
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162
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Basso K. Toward a systems biology approach to investigate cellular networks in normal and malignant B cells. Leukemia 2009; 23:1219-25. [PMID: 19194469 DOI: 10.1038/leu.2009.4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
In recent years, we experienced an increasing development of new technologies that aim to comprehensively dissect the molecular genetics of cellular phenotypes. Pioneering studies have been performed on leukemia and lymphoma and then extended to many other types of malignancies. Genome-wide technologies allow taking snapshots of defined cellular context from an unbiased angle highlighting a complexity that we still struggle to fully interpret. The increasing availability of technologies to detect genetic, transcriptional and post-transcriptional characteristics of cellular systems needs to be associated with the development of computational tools to fully investigate these data in an integrated way. The evolution of different genome-wide technologies as well as data mining and integration tools will be discussed following studies performed on normal and malignant human mature B cells.
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Affiliation(s)
- K Basso
- Institute for Cancer Genetics, Columbia University, New York, NY 10032, USA.
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163
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Vogl UM, Berger W, Micksche M, Pirker C, Lamm W, Pichelmeyer O, Zielinski CC, Schmidinger M. Synergistic effect of Sorafenib and Sunitinib with Enzastaurin, a selective protein kinase C inhibitor in renal cell carcinoma cell lines. Cancer Lett 2009; 277:218-26. [PMID: 19171421 DOI: 10.1016/j.canlet.2008.12.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2008] [Revised: 12/06/2008] [Accepted: 12/08/2008] [Indexed: 01/13/2023]
Abstract
Enzastaurin (LY317615.HCl) is an oral selective PKC-beta inhibitor with antiproliferative efficacy in various tumor models. This study was designed to investigate whether combination therapy with Enzastaurin and other targeted agents including Sorafenib and Sunitinib enhanced anti-tumor efficacy in renal cell carcinoma cell lines. Enzastaurin alone presented not active in renal cell carcinoma cell lines. Both Sorafenib and Sunitinib with Enzastaurin at concentrations feasible in vivo showed a synergistic reduction of viable RCC cells by inhibiting cell growth through inhibition of phospho-S6-kinase and GSK3-beta. The combination of Enzastaurin with Sorafenib and Sunitinib seems highly encouraging and warrants further investigation in vivo.
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Affiliation(s)
- Ursula Maria Vogl
- Clinical Division of Oncology, Department of Medicine I, Medical University Vienna, Waehringer Guertel 18-20, Vienna, Austria.
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164
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Abstract
Diffuse large B-cell lymphoma (DLBCL) remains a curable lymphoma, with improved outcome resulting in large part from the incorporation of rituximab in standard regimens. The disease is heterogeneous clinically, morphologically, and molecularly. Recent insights into the molecular heterogeneity of DLBCL are beginning to yield novel therapeutics with significant promise for key subsets of patients. Although cyclophosphamide, hydroxydaunorubicin, vincristine, and prednisone chemotherapy with rituximab remains a standard therapeutic approach for most patients who have DLBCL, it is anticipated that novel agents will be included in treatment regimens for many patients in the near future.
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Affiliation(s)
- Jonathan W Friedberg
- James P. Wilmot Cancer Center, University of Rochester, 601 Elmwood Avenue, Box 704, Room 1-4118C, Rochester, NY 14642, USA.
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165
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Teicher BA. In vivo/ex vivo and in situ assays used in cancer research: a brief review. Toxicol Pathol 2008; 37:114-22. [PMID: 19098118 DOI: 10.1177/0192623308329473] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Predicting whether a potential new anticancer agent will have a positive therapeutic index in patients remains a challenge. This brief review provides examples of preclinical in vivo/ex vivo and in situ assays used to assess the therapeutic potential of experimental anticancer therapeutics. Excision assays involving removal of tumor, bone marrow, and other tissues from the host after treatment to determine the effects of therapy in ex vivo assays are important preclinical tools. The survival of malignant cells from tumors treated in vivo and then excised is often determined by colony formation (CFU) in culture. When mice bearing in vivo alkylating agent-resistant tumors were treated with anticancer drugs such as cyclophosphamide, the survival pattern of bone marrow granulocyte-macrophage-colony forming units (CFU-GM) paralleled tumor cell survival. When TNP-470 and minocycline, an antiangiogenic combination, were added to treatment with cytotoxic anticancer therapies, tumor response markedly increased. TNP-470/minocycline-treated mice had higher tissue drug levels than did mice treated with the drug alone. Enzastaurin, an antiangiogenic protein kinase Cbeta inhibitor, treatment decreased intratumoral vessels to one half to one quarter of controls. Simultaneous and sequential treatment regimens with enzastaurin and BCNU delayed tumor growth and increased lifespan in mice bearing subcutaneous or intracranial human T98G glioblastoma multiforme. Both TNP-470 and enzastaurin have undergone clinical trials. Enzastaurin is currently in Phase III clinical trials.
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Affiliation(s)
- Beverly A Teicher
- Genzyme Corporation, 49 New York Avenue, Framingham, MA 01701-9322, USA.
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166
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Sud R, Friedberg JW. Salvage therapy for relapsed or refractory diffuse large B-cell lymphoma: impact of prior rituximab. Haematologica 2008; 93:1776-80. [PMID: 19050068 PMCID: PMC2898124 DOI: 10.3324/haematol.2008.000984] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
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167
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Abramson JS, Chen W, Juszczynski P, Takahashi H, Neuberg D, Kutok JL, Takeyama K, Shipp MA. The heat shock protein 90 inhibitor IPI-504 induces apoptosis of AKT-dependent diffuse large B-cell lymphomas. Br J Haematol 2008; 144:358-66. [PMID: 19036086 DOI: 10.1111/j.1365-2141.2008.07484.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Heat shock protein 90 (HSP90) is a molecular chaperone that stabilizes critical client proteins in multiple cancers. Gene expression profiling was utilized to characterize HSP90 isoform expression in primary human diffuse large B-cell lymphomas (DLBCLs). HSP90 alpha and beta isoforms were differentially expressed in subsets of tumours defined by their transcriptional profiles. Thereafter, we assessed the activity of the HSP90 inhibitor, IPI-504, in an extensive panel of DLBCL cell lines. IPI-504, which interacts with the conserved ATP-binding site in both HSP90 isoforms, inhibited proliferation and induced apoptosis in the majority of DLBCL cell lines at low micromolar concentrations. IPI-504-sensitive cell lines expressed high levels of the HSP90 client protein, pAKT, and exhibited dose-dependent decreases in pAKT levels following IPI-504 treatment and significantly reduced proliferation following AKT RNAi. Furthermore, the combination of low-dose (<1 micromol/l) IPI-504 and the AKT/Pi3K pathway inhibitor, LY24009, was synergistic in IPI-504-sensitive DLBCL cell lines. Low-dose IPI-504 was also synergistic with the chemotherapeutic agent, doxorubicin. The HSP90 inhibitor IPI-504 warrants further investigation in DLBCL alone and in combination with identified client protein inhibitors and active chemotherapeutic agents.
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Affiliation(s)
- Jeremy S Abramson
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02115, USA
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168
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Abstract
BACKGROUND Constituting approximately 30% of lymphoid malignancies, diffuse large B-cell lymphoma (DLBCL) is the most common aggressive lymphoma in adults worldwide. The clinical and biologic heterogeneity that exists in DLBCL suggests that this entity might actually be comprised of several distinct neoplasms that could require different therapeutic approaches. DLBCL was considered incurable until combination chemotherapy became available. OBJECTIVE Current treatment strategies for the treatment of untreated and relapsed advanced-stage DLBCL are reviewed; novel treatments for DLBCL are discussed. METHODS Relevant literature was identified using the PubMed search engine and by reviewing abstracts from major conference proceedings. RESULTS/CONCLUSION Recently, novel therapeutic strategies, including the incorporation of immunotherapy to combination chemotherapy, have improved outcome for patients with DLBCL with cure rates exceeding 50%, especially in younger patients.
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Affiliation(s)
- Maricer P Escalón
- University of Miami Sylvester Cancer Center, 1475 NW 12 Ave Suite 3400 (D8-4), Miami, FL 33136, USA.
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169
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Abstract
BACKGROUND Enzastaurin is a novel antineoplastic and antiangiogenic agent that acts through inhibition of protein kinase C (PKC). OBJECTIVE This review summarizes the scientific rationale and current clinical evidence for the use of enzastaurin in oncology. METHODS We performed a systematic review of the literature using the keywords protein kinase C-beta and enzastaurin in order to characterize the therapeutic target PKC-beta. We then reviewed the in-vitro, Phase I, and Phase II data for enzastaurin with a focus on hematologic malignancies. RESULTS/CONCLUSIONS After preliminary Phase I trials established a favorable toxicity profile, enzastaurin has been studied in completed and ongoing Phase II and III studies in solid and hematologic malignancies, including B-cell lymphomas where the rationale for its use is most promising.
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Affiliation(s)
- Yi-Bin Chen
- Dana Farber Cancer Institute, Massachusetts General Hospital, GRB 740, 44 Binney Street, Boston, MA 02115, USA
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170
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Decker T, Sandherr M, Goetze K, Oelsner M, Ringshausen I, Peschel C. A pilot trial of the mTOR (mammalian target of rapamycin) inhibitor RAD001 in patients with advanced B-CLL. Ann Hematol 2008; 88:221-7. [PMID: 18704419 DOI: 10.1007/s00277-008-0582-9] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2008] [Accepted: 07/24/2008] [Indexed: 11/29/2022]
Abstract
Although B-cell chronic lymphocytic leukemia (CLL) is treatable, it remains an incurable disease and most patients inevitably suffer relapse. Many therapeutic options exist for those requiring therapy, including monoclonal antibodies and stem cell transplantation, but remissions tend to last shorter in the course of the disease. Targeting the cell cycle has recently been realized to be an attractive therapeutic approach in solid and hematological malignancies, and the proliferative nature of B-CLL is increasingly accepted. Here, we report data on a phase II pilot trial with the oral mammalian target of rapamycin (mTOR) inhibitor RAD001 5 mg/daily in patients with advanced B-CLL who had progressive disease after at least two lines of treatment. After treatment of seven patients, this trial was stopped because of toxicity concerns, although some degree of activity was observed (one partial remission, three patients with stable disease). Interestingly, cyclin E expression decreased in responding patients. Further strategies of mTOR inhibition by RAD001 in B-CLL should focus on different treatment schedules, adequate anti-infectious prophylaxis, or combinations with cytotoxic drugs.
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Affiliation(s)
- Thomas Decker
- III. Department of Medicine, Technical University of Munich, Ismaningerstr. 15, 81675 Munich, Germany.
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Blumberg PM, Kedei N, Lewin NE, Yang D, Czifra G, Pu Y, Peach ML, Marquez VE. Wealth of opportunity - the C1 domain as a target for drug development. Curr Drug Targets 2008; 9:641-52. [PMID: 18691011 PMCID: PMC3420355 DOI: 10.2174/138945008785132376] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The diacylglycerol-responsive C1 domains of protein kinase C and of the related classes of signaling proteins represent highly attractive targets for drug development. The signaling functions that are regulated by C1 domains are central to cellular control, thereby impacting many pathological conditions. Our understanding of the diacylglycerol signaling pathways provides great confidence in the utility of intervention in these pathways for treatment of cancer and other conditions. Multiple compounds directed at these signaling proteins, including compounds directed at the C1 domains, are currently in clinical trials, providing strong validation for these targets. Extensive understanding of the structure and function of C1 domains, coupled with detailed insights into the molecular details of ligand - C1 domain interactions, provides a solid basis for rational and semi-rational drug design. Finally, the complexity of the factors contributing to ligand - C1 domain interactions affords abundant opportunities for manipulation of selectivity; indeed, substantially selective compounds have already been identified.
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Affiliation(s)
- P M Blumberg
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Center, Bethesda, MD 20892, USA.
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Rieger J, Lemke D, Maurer G, Weiler M, Frank B, Tabatabai G, Weller M, Wick W. Enzastaurin-induced apoptosis in glioma cells is caspase-dependent and inhibited by BCL-XL. J Neurochem 2008; 106:2436-48. [PMID: 18662322 DOI: 10.1111/j.1471-4159.2008.05586.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The novel protein kinase C-beta inhibitor enzastaurin (ENZA) induced apoptosis in LNT-229 and T98G cells whereas A172 cells were resistant. Further, ENZA reduced proliferation in glioblastoma-initiating cells T 269 and T 323 but did not induce apoptosis. ENZA-induced apoptosis involved cleavage of caspases 3, 8, and 9 and led to mitochondrial cytochrome c release and was strongly suppressed by the broad spectrum caspase inhibitor zVAD-fmk but only slightly by the expression of the viral caspase 1/8 inhibitor cytokine response modifier-A. ENZA did not reduce the phosphorylation of protein kinase B (Akt), but of p70 S6 kinase and of its substrate S6 protein in T98G cells. Inhibition of the phosphatidylinositol 3 kinase signaling pathway did not restore sensitivity of A172 cells towards ENZA, and constitutively active Akt did not protect LNT-229 and T98G cells from ENZA-induced apoptosis. Dephosphorylation of glycogen synthase kinase 3beta, a biomarker of ENZA action, and cell death induction by ENZA were separately regulated. Inhibition or activation of Akt only weakly modulated ENZA-induced dephosphorylation of glycogen synthase kinase 3beta. In ENZA-resistant A172 cells, apoptosis ligand 2 (Apo2L.0)-induced cleavage of caspases 3, 8, and 9 was increased by ENZA, resulting in synergistic activity of ENZA and Apo2L.0.
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Affiliation(s)
- Johannes Rieger
- Laboratory of Molecular Neuro-Oncology, Department of General Neurology, University of Tübingen, Tübingen, Germany
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173
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Leonard JP, Martin P, Barrientos J, Elstrom R. Targeted Treatment and New Agents in Diffuse Large B-Cell Lymphoma. Semin Hematol 2008; 45:S11-6. [DOI: 10.1053/j.seminhematol.2008.07.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Abstract
Neurotoxic side effects of cancer therapy are second in frequency to hematological toxicity. Unlike hematological side effects that can be treated with hematopoietic growth factors, neuropathies cannot be treated and protective treatment strategies have not been effective. For the neurologist, the diagnosis of a toxic neuropathy is primarily based on the case history, the clinical and electrophysiological findings, and knowledge of the pattern of neuropathy associated with specific agents. In most cases, toxic neuropathies are length-dependent, sensory, or sensorimotor neuropathies often associated with pain. The platinum compounds are unique in producing a sensory ganglionopathy. Neurotoxicity is usually dependent on cumulative dose. Severity of neuropathy increases with duration of treatment and progression stops once drug treatment is completed. The platinum compounds are an exception where sensory loss may progress for several months after cessation of treatment ("coasting"). As more effective multiple drug combinations are used, patients will be treated with several neurotoxic drugs. Synergistic neurotoxicity has not been extensively investigated. Pre-existent neuropathy may influence the development of a toxic neuropathy. Underlying inherited or inflammatory neuropathies may predispose patients to developing very severe toxic neuropathies. Other factors such as focal radiotherapy or intrathecal administration may enhance neurotoxicity. The neurologist managing the cancer patient who develops neuropathy must answer a series of important questions as follows: (1) Are the symptoms due to peripheral neuropathy? (2) Is the neuropathy due to the underlying disease or the treatment? (3) Should treatment be modified or stopped because of the neuropathy? (4) What is the best supportive care in terms of pain management or physical therapy for each patient? Prevention of toxic neuropathies is most important. In patients with neuropathy, restorative approaches have not been well established. Symptomatic and other management are necessary to maintain and improve quality of life.
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Affiliation(s)
- Anthony J Windebank
- Division of Neuroscience, Department of Neurology, Mayo Clinic College of Medicine, Rochester, MN 55905, USA.
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175
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Kassam S, Montoto S. Oncologic, Endocrine & Metabolic Emerging drugs in B-cell non-Hodgkin's lymphoma. Expert Opin Emerg Drugs 2008; 13:323-43. [DOI: 10.1517/14728214.13.2.323] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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176
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Jasinski P, Terai K, Zwolak P, Dudek AZ. Enzastaurin renders MCF-7 breast cancer cells sensitive to radiation through reversal of radiation-induced activation of protein kinase C. Eur J Cancer 2008; 44:1315-22. [PMID: 18448327 DOI: 10.1016/j.ejca.2008.03.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2007] [Revised: 01/10/2008] [Accepted: 03/26/2008] [Indexed: 01/27/2023]
Abstract
Enzastaurin (LY317615.HCI), a protein kinase C (PKC)-beta inhibitor, has a radiosensitising effect on 4T1 murine breast cancer and human glioma cells; however, the exact mechanism of this action has not been evaluated. The present study investigated the effects of enzastaurin and gamma irradiation on PKC activity in MCF-7 human breast cancer cells in vitro and in vivo. Enzastaurin (5 microM) in combination with irradiation (2-8 Gy) produced a synergistic decline in MCF-7 clonogenic cell survival. Analysis of MCF-7 cells stained with Annexin V and 7-aminoactinomycin D showed a dose-dependent increase in apoptosis in response to enzastaurin (3, 5 and 7 microM) and irradiation (10 Gy) compared to irradiation alone. This pro-apoptotic effect was confirmed by increases in caspase-3 and -9 activity. In a MCF-7 xenograft model, irradiation with 25 Gy increased PKC-alpha activity by 2.5-fold compared to untreated controls, whereas PKC-epsilon and -betaII activity was increased by 1.8-fold. Radiation-induced activation of all three anti-apoptotic isoforms of PKC was reversed by pre-treatment with enzastaurin (75 mg/kg, twice daily for 3 days). We conclude that enzastaurin has a radiosensitising effect on MCF-7 human xenograft tumours through the reversal of anti-apoptotic activation of PKC isoforms.
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Affiliation(s)
- Piotr Jasinski
- Division of Hematology, Oncology and Transplantation, Department of Medicine, University of Minnesota, 420 Delaware Street SE, Minneapolis, MN 55455, USA
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178
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Abstract
Mantle cell lymphoma (MCL) represents 6% of non-Hodgkin lymphomas, but is one of the most active fields of clinical investigation. Unfortunately, there is still no standard or curative therapy in MCL. Front-line therapy appears to benefit from intensification either through high-dose therapy with stem cell transplant consolidation or dose-intense chemotherapy with hyperfractionated cyclophosphamide, vincristine, adriamycin/doxorubicin and dexamethasone/rituximab. Most patients still relapse and a multitude of novel agents are currently being tested in this setting, including proteasome inhibitors with bortezomib (the first of its class and the first US FDA-approved drug for MCL), mTOR inhibitors, Bcl-2 inhibitors, antiangiogenesis agents and histone deacetylase inhibitors among others. An obvious effort is needed to enroll patients on clinical trials, the design of which might benefit from pharmacogenomics and a better understanding of MCL biology and its diversity.
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Affiliation(s)
- K Stephen Suh
- Jurist Research Center, 30 Prospect Avenue, Hackensack NJ 07601, USA
| | - Andre Goy
- HUMC Cancer Center, 20 Prospect Avenue, Hackensack NJ 07601, USA
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Seshadri T, Kuruvilla J, Crump M, Keating A. Salvage therapy for relapsed/refractory diffuse large B cell lymphoma. Biol Blood Marrow Transplant 2008; 14:259-67. [PMID: 18275892 DOI: 10.1016/j.bbmt.2007.11.013] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2007] [Accepted: 11/30/2007] [Indexed: 11/26/2022]
Abstract
Diffuse large B cell lymphoma (DLBCL), the most common subtype of aggressive lymphoma, has considerable biologic and clinical heterogeneity. Despite recent therapeutic advances, up to 50% of patients relapse after standard chemoimmunotherapy. The International Prognostic Index (IPI) at relapse is of value in providing prognostic information on response to salvage chemotherapy and outcome after autologous hematopoietic cell transplantation (aHCT). Predictive biologic and gene expression markers, however, remain undefined, and require further clarification from additional molecular studies. To date, the standard of care in the management of relapsed/refractory DLBCL is salvage chemotherapy followed by an aHCT for those with chemotherapy-sensitive disease. Currently, there is no standard salvage chemotherapy regimen, and the use of immunotherapy for relapsed disease requires further evaluation. This review focuses on prognostic markers, current salvage therapies, and discusses the role of novel treatment in the management of relapsed/refractory DLBCL.
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Affiliation(s)
- Tara Seshadri
- Autologous Blood and Marrow Transplant Program, Princess Margaret Hospital, Toronto, Ontario, Canada.
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A phase I safety, tolerability, and pharmacokinetic study of enzastaurin combined with capecitabine in patients with advanced solid tumors. Anticancer Drugs 2008; 19:77-84. [PMID: 18043132 DOI: 10.1097/cad.0b013e3282f077b3] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Enzastaurin, an oral inhibitor of protein kinase Cbeta, affects signal transduction associated with angiogenesis, proliferation, and survival. Capecitabine is converted to 5-fluoruracil by thymidine phosphorylase, a putative angiogenic factor. The all-oral combination of the two drugs offers the potential for targeting angiogenesis in capecitabine-sensitive tumors with nonoverlapping toxicities. Patients with advanced cancer initially received single-agent enzastaurin to achieve steady-state concentrations (cycle 1). In subsequent 21-day cycles, enzastaurin was given orally, once daily, on days 1-21 and capecitabine orally, twice daily (b.i.d.), on days 1-14 in three dose-level cohorts. Three dose-escalation cohorts were studied: cohort 1 (n=8), 350 mg of enzastaurin +capecitabine (750 mg/m2 b.i.d.); cohort 2 (n=7), enzastaurin (350 mg)+capecitabine (1000 mg/m2 b.i.d.); cohort 3 (n=12), 525-mg capsules or 500-mg enzastaurin+capecitabine (1000 mg/m2 b.i.d.). Further dose escalation was not pursued because of emerging data that enzastaurin systemic exposure did not increase at doses above 525 mg. Although a traditional toxicity-based maximum tolerated dose was not achieved, the highest dosing cohort represented a biologically relevant dose of enzastaurin, on the basis of preclinical data and correlative pharmacodynamic biomarker assays of protein kinase Cbeta inhibition in peripheral blood mononucleocytes, in combination with a standard dose of capecitabine. For the 500/525-mg dose, ratios of total enzastaurin analyte geometric means (i.e. enzastaurin alone versus enzastaurin with capecitabine) reflected a trend toward decreased enzastaurin exposure, but did not reach statistical significance. The pharmacokinetic parameters of capecitabine with enzastaurin were similar to those previously reported for single-agent capecitabine. The regimen was well tolerated, without any consistent pattern of drug-related grade 3 or grade 4 toxicities being observed. Although no objective tumor responses were documented, five patients maintained stable disease for >or=6 months (range: 6-9.7 months). The recommended phase II dose of this combination, based on the results of this study, is enzastaurin at a daily dose of 500 mg (tablet formulation) and capecitabine (1000 mg/m2, b.i.d.) on days 1-14 every 21 days. Further disease-directed studies are warranted, such as in malignancies in the treatment of which both capecitabine and inhibitors of angiogenesis have previously been benchmarked as being effective.
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182
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Current Awareness in Hematological Oncology. Hematol Oncol 2008. [DOI: 10.1002/hon.830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Abstract
PURPOSE OF REVIEW Enzastaurin - a novel oral antitumor agent that selectively inhibits protein kinase Cbeta activity - has demonstrated promise in phase I and II trials in various advanced cancers, and is being investigated in multiple hematologic malignancies and solid tumors. RECENT FINDINGS Enzastaurin (LY317615) was initially developed as an antiangiogenic cancer therapy. Subsequent preclinical studies showed its antitumor effect by inhibiting tumor proliferation and inducing apoptosis on multiple cancer cell lines as well as xenograft models. Enzastaurin not only inhibits protein kinase Cbeta activity but also suppresses signaling through the phosphoinositide-3 kinase/AKT pathway. Based on the phase I study, 525 mg/day is the recommended dose for oral enzastaurin. It is well tolerated at this dose, with no clinically significant grade 3 or 4 toxicities. A recent phase II study of enzastaurin in patients with relapsed or refractory diffuse large B-cell lymphoma showed enzastaurin to be associated with prolonged freedom from progression. Several preliminary studies showed promising results in patients with various advanced cancers and suggested that enzastaurin can be safely used long term in combination with traditional chemotherapies. SUMMARY Enzastaurin is emerging as a promising new antitumor treatment. This review addresses the mechanism of action, development, preclinical studies, and clinical study results with enzastaurin.
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Affiliation(s)
- Shuo Ma
- Division of Hematology/Oncology, Department of Medicine, Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, Illinois 60611, USA
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184
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Podar K, Raab MS, Chauhan D, Anderson KC. The therapeutic role of targeting protein kinase C in solid and hematologic malignancies. Expert Opin Investig Drugs 2007; 16:1693-707. [PMID: 17922632 DOI: 10.1517/13543784.16.10.1693] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The protein kinase C (PKC) family, the most prominent target of tumor-promoting phorbol esters, is functionally linked to cell differentiation, growth, survival, migration and tumorigenesis and so mediates tumor cell proliferation, survival, multidrug resistance, invasion, metastasis and tumor angiogenesis. Therefore, targeting PKC isozymes may represent an attractive target for novel anticancer therapies. Recent preclinical and clinical studies using the macrocyclic bisindolylmaleimide enzastaurin or the N-benzylstaurosporine midostaurin demonstrate promising activity of PKC inhibitors in a variety of tumors, including diffuse large B-cell lymphoma, multiple myeloma and Waldenstroem's macroglobulinemia. However, our knowledge of PKCs in tumorigenesis is still only partial and each PKC isoform may contribute to tumorigenesis in a distinct way. Specifically, PKC isoforms have vastly different roles, which vary depending on expression levels of organ and tissue distribution, cell type, intracellular localization, protein-protein and lipid-protein interactions and the biologic environment. Although PKC activation generally positively affects tumor cell growth, motility, invasion and metastasis, recent reports show that many PKCs can also have negative effects. Therefore, it is necessary to further dissect the relative contribution of PKC isozymes in the development and progression of specific tumors in order to identify therapeutic opportunities, using either PKC inhibitors or PKC activators.
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Affiliation(s)
- Klaus Podar
- Dana-Farber Cancer Institute, Department of Medical Oncology, Jerome Lipper Multiple Myeloma Center, 44 Binney Street, Boston, MA 02115, USA.
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185
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Morschhauser F, Seymour JF, Kluin-Nelemans HC, Grigg A, Wolf M, Pfreundschuh M, Tilly H, Raemaekers J, van 't Veer MB, Milpied N, Cartron G, Pezzutto A, Spencer A, Reyes F, Dreyling M. A phase II study of enzastaurin, a protein kinase C beta inhibitor, in patients with relapsed or refractory mantle cell lymphoma. Ann Oncol 2007; 19:247-53. [PMID: 17906297 DOI: 10.1093/annonc/mdm463] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Protein kinase C beta (PKCbeta), a pivotal enzyme in B-cell signaling and survival, is overexpressed in most cases of mantle cell lymphoma (MCL). Activation of PI3K/AKT pathway is involved in pathogenesis of MCL. Enzastaurin, an oral serine/threonine kinase inhibitor, suppresses signaling through PKCbeta/PI3K/AKT pathways, induces apoptosis, reduces proliferation, and suppresses tumor-induced angiogenesis. PATIENTS AND METHODS Patients with relapsed/refractory MCL, and no more than four regimens of prior therapy, received 500 mg enzastaurin, orally, once daily. RESULTS Sixty patients, median age 66 years (range 45-85), Eastern Cooperative Oncology Group performance status of zero to two (48% had baseline International Prognostic Index of 3-5), were enrolled. Most patients had prior CHOP-like chemotherapy and/or rituximab (median = 2 regimens). No drug-related deaths occurred. There was one case each of grade 3 anemia, diarrhea, dyspnea, vomiting, hypotension, and syncope. Fatigue was the most common toxicity. Although no objective tumor responses occurred, 22 patients (37%, 95% CI 25% to 49%) were free from progression (FFP) for > or =3 cycles (one cycle = 28 days); 6 of 22 were FFP for >6 months. Two patients remain on treatment and FFP at >23 months. CONCLUSION Freedom from progression for >6 months in six patients and a favorable toxicity profile with minimal hematological toxicity indicate that enzastaurin warrants evaluation as maintenance therapy and combination chemotherapy in MCL.
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Affiliation(s)
- F Morschhauser
- Hematology, Hopital C. Huriez Centre Hospitalier Universitaire, Lille, France.
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186
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Mihelic R, Kaufman J, Lonial S, Flowers C. Maintenance Therapy in Lymphoma. ACTA ACUST UNITED AC 2007; 7:507-13. [DOI: 10.3816/clm.2007.n.034] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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187
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Abstract
Mantle cell lymphoma (MCL) represents only 6% of non-Hodgkin's lymphoma but is one of the most active fields of clinical investigation. Front-line therapy appears to benefit from intensification either through high-dose therapy with stem cell transplant consolidation or dose-intense chemotherapy with hyper-CVAD (fractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone) and rituximab. Unfortunately, no standard therapy has been defined, and most patients eventually relapse. An impressive number of novel agents are currently being tested, the bulk of which are biologic agents or targeted therapies. Bortezomib is the first in class of proteasome inhibitors and the first new agent to be approved in relapsed/refractory MCL. Other small molecules have shown encouraging activity, including mTOR and Bcl-2 inhibitors, novel antibodies, and new cytotoxic agents. Future trials will also benefit from new molecular approaches through pharmacogenomics.
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Affiliation(s)
- Andre Goy
- Lymphoma Division, Hackensack Medical University Cancer Center, 20 Prospect Avenue, Hackensack, NJ 07601, USA.
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188
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Abstract
Abstract
Diffuse large B-cell lymphomas (DLBCLs), the most common lymphoid malignancies, are clinically and genetically heterogeneous disorders. Although DLBCL is a chemo-responsive tumor, many patients will not be cured with conventional empiric treatment regimens. Gene expression profiles, analyses of specific genetic abnormalities and functional assays have been used to develop comprehensive molecular signatures of tumors that share similar features and rely upon common survival pathways. These studies are leading to the identification of subtype-specific rational therapeutic targets and associated inhibitors for clinical investigation.
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