Proteasome inhibition in myelodysplastic syndromes and acute myelogenous leukemia cell lines
ABSTRACT In this work, effects of bortezomib on apoptosis, clonal progenitor growth, cytokine production, and NF-κB expression in patients with MDS with cytopenias requiring transfusion support are examined. Bortezomib increased apoptosis in marrow mononuclear cells but had no effects on CFU-GM, BFU-E, or CFU-L content. No consistent effects on NF-κB activation in vivo were noted. To further define the role of bortezomib in AML and MDS, we examined it in combination with several targeted agents and chemotherapeutic agents in vitro. Combinations with arsenic trioxide, sorafenib, and cytarabine demonstrated synergistic in vitro effects in AML cell lines.
- SourceAvailable from: Sudipto Mukherjee
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- "The ORR was 56%, with 14 achieving hematologic improvement . Bortezomib is a proteasome and NF-kb inhibitor that can induce apoptosis in vitro in MDS/AML leukemia bone marrow cells  and has demonstrated benefit when used as a single agent in MDS patients . Bortezomib has been studied in combination with lenalidomide, low-dose cytarabine (LDAC) and the HDACi Belinostat in patients with AML and higher-risk MDS, though its benefit remains unclear [86e88]. "
ABSTRACT: The myelodysplastic syndromes (MDS) are a heterogenous collection of clonal hematopoietic malignancies that exist as a subgroup of the myeloid neoplasms as classified by the World Health Organization (WHO). They are characterized by ineffective hematopoiesis, subsequent cytopenias, transformation to acute myeloid leukemia (AML), and poor overall survival. There are currently three FDA-approved medications for MDS; lenalidomide, azacitidine, and decitabine. The role of these agents is to diminish the clinical impact of MDS and delay its progression to AML. However, despite known results with these monotherapies, recent clinical trials with a variety of combinations for MDS have demonstrated promising results. These trials include combinations of hypomethylating agents, histone deacetylase inhibitors, growth factors, and chemotherapy among others. In this paper we review the current literature on combination therapies in MDS, analyze on-going and concluded trials, and suggest future possibilities for combination strategies in MDS. Copyright © 2014 Elsevier Ltd. All rights reserved.Bailliè re s Best Practice and Research in Clinical Haematology 11/2014; 28(1). DOI:10.1016/j.beha.2014.11.002 · 2.55 Impact Factor
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ABSTRACT: Abstract The 5q deletion is a chromosomal abnormality that is observed in a subset of myelodysplastic syndromes (MDS). When isolated, this abnormality defines a specific clinical syndrome termed MDS associated with isolated deletion 5q, presenting with macrocytic anemia, normal platelet count or slight thrombocytosis, hypolobated megakaryocytes and fewer than 5% blasts in the bone marrow. MDS with the 5q deletion have a particular sensitivity to treatment with lenalidomide, a thalidomide analog. In this article, molecular changes in 5q- MDS derived from haploinsufficiency of genes encoded from the deleted region in 5q are reviewed, and mechanisms that link these molecular lesions with lenalidomide sensitivity are proposed.Leukemia & lymphoma 09/2011; 53(5):779-88. DOI:10.3109/10428194.2011.623255 · 2.61 Impact Factor
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ABSTRACT: PURPOSEThe purpose of this study was to determine remission induction frequency when bortezomib was combined with daunorubicin and cytarabine in previously untreated older adults with acute myeloid leukemia (AML) and safety of bortezomib in combination with consolidation chemotherapy consisting of intermediate-dose cytarabine (Int-DAC). PATIENTS AND METHODS Ninety-five adults (age 60 to 75 years; median, 67 years) with previously untreated AML (including therapy-related and previous myelodysplastic syndrome) received bortezomib 1.3 mg/m(2) intravenously (IV) on days 1, 4, 8, and 11 with daunorubicin 60 mg/m(2) on days 1 through 3 and cytarabine 100 mg/m(2) by continuous IV infusion on days 1 through 7. Patients who achieved complete remission (CR) received up to two courses of consolidation chemotherapy with cytarabine 2 gm/m(2) on days 1 through 5 with bortezomib. Three cohorts with escalating dose levels of bortezomib were tested (0.7, 1.0, and 1.3 mg/m(2)). Dose-limiting toxicities were assessed during the first cycle of consolidation. The relationship between cell surface expression of CD74 and clinical outcome was assessed.ResultsFrequency of CR was 65% (62 of 95), and 4% of patients (four of 95) achieved CR with incomplete platelet recovery (CRp). Eleven patients developed grade 3 sensory neuropathy. Bortezomib plus Int-DAC proved tolerable at the highest dose tested. Lower CD74 expression was associated with CR/CRp (P = .04) but not with disease-free or overall survival. CONCLUSION The addition of bortezomib to standard 3 + 7 daunorubicin and cytarabine induction chemotherapy for AML resulted in an encouraging remission rate. The maximum tested dose of bortezomib administered in combination with Int-DAC for remission consolidation was 1.3 mg/m(2) and proved tolerable. Further testing of this regimen is planned.Journal of Clinical Oncology 11/2012; 31(7). DOI:10.1200/JCO.2012.45.2177 · 18.43 Impact Factor