scholarly journals A metabolic switch in proteasome inhibitor-resistant multiple myeloma ensures higher mitochondrial metabolism, protein folding and sphingomyelin synthesis

Haematologica ◽  
2019 ◽  
Vol 104 (9) ◽  
pp. e415-e419 ◽  
Author(s):  
Lenka Besse ◽  
Andrej Besse ◽  
Max Mendez-Lopez ◽  
Katerina Vasickova ◽  
Miroslava Sedlackova ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Protein Folding ◽  
Proteasome Inhibitor ◽  
Mitochondrial Metabolism ◽  
Metabolic Switch

Differential Effects of Hsp70 Inhibition within the Tumor and Microenvironment in Multiple Myeloma.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 5070-5070
Author(s):  
Marc J. Braunstein ◽  
Na Liu ◽  
Uwe Klueppelberg ◽  
Craig Scott ◽  
Shannon Behrman ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Protein Folding ◽  
Cell Lines ◽  
Proteasome Inhibitor ◽  
Time Course ◽  
Proteasome Inhibitors ◽  
Apoptotic Response ◽  
Inhibition Of Proliferation ◽  
Drug Concentrations ◽  
Ig Synthesis

Abstract Multiple myeloma (MM) remains fatal despite prolonged survival by recent advances in treatment, including the use of proteasome inhibitors. It has been proposed that proteasome inhibitors target MM by modulating the NF-κB pathway. Alternatively, proteasome inhibitors may target MM cells because the proteasome helps alleviate the unfolded protein response (UPR) that results from the accumulation of aberrant proteins in the endoplasmic reticulum (ER), which in turn may trigger apoptosis. Indeed, the UPR is induced in neoplastic plasma cells, possibly because of increased immunoglobulin (IG) synthesis that exceeds the protein folding capacity of the ER. Consequently, the degree to which inhibition of the proteasome induces apoptosis may be related to the concentration of unfolded light chains within the ER in MM. We therefore examined whether inhibition of a protein-folding mediator, the Hsp70 molecular chaperone, results in synergistic induction of MM cell apoptosis when combined with a proteasome inhibitor. To this end, the effects of MAL3-101, a novel inhibitor of Hsp70 function, both alone and in combination with a proteasome inhibitor (MG132) on three MM cell lines as well as primary patient MM cells were examined. Dose-response and time course studies in MM cell lines U266, RPMI-8226, and NCI-H929 showed increasing apoptosis and inhibition of proliferation after 16 hours of exposure to MAL3-101 (IC50: 0.9 μM) or to MG132 (IC50: 7 μM). Strikingly, when sub-effective concentrations of MG132 and MAL3-101 were combined, a strong, synergistic apoptotic response was observed in the NCI cell line after 16 hours, and synergistic effects were observed in all cell lines after 36 hours of exposure to the two drugs. Next, we studied MM cells and endothelial progenitor cells (EPCs) derived from the bone marrow of five untreated patients. These two cell populations, which were shown to bear clonotypic similarities, also showed sensitivity to dual targeting. However, these effects occurred at drug concentrations different than those found to be most potent in the cell lines. Moreover, semi-quantitative RT-PCR studies indicated that RPMI cells but not U266 cells exhibited a strong UPR induction after 16 hours of exposure to 7 μM MG132. These data correlated with the greater degree of IG secretion observed in RPMI cells compared to U266 cells as assessed by pulse-chase analysis. Taken together, these results suggest that the apoptotic response of MM cells via targeting the UPR and ER stress pathways may be dependent on basal protein production, including IG synthesis. Studies relating the secretion “index” to UPR induction and sensitivity to Hsp70 and proteasome inhibition in primary tumor cells as well as in microvascular cells from MM patients are ongoing.

scholarly journals Anti-tumor activity of a novel proteasome inhibitor D395 against multiple myeloma and its lower cardiotoxicity compared with carfilzomib

2021 ◽  
Vol 12 (5) ◽  
Author(s):  
Xuxing Shen ◽  
Chao Wu ◽  
Meng Lei ◽  
Qing Yan ◽  
Haoyang Zhang ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Proteasome Inhibitor ◽  
Osteoclast Differentiation ◽  
Dependent Manner ◽  
Serum Enzyme ◽  
Herg Channels ◽  
Anti Tumor Activity ◽  
Dose Dependent

AbstractCarfilzomib, a second-generation proteasome inhibitor, has significantly improved the survival rate of multiple myeloma (MM) patients, but its clinical application is still restricted by drug resistance and cardiotoxicity. Here, we identified a novel proteasome inhibitor, D395, and assessed its efficacy in treating MM as well as its cardiotoxicity at the preclinical level. The activities of purified and intracellular proteasomes were measured to determine the effect of D395 on the proteasome. CCK-8 and flow cytometry experiments were designed to evaluate the effects of D395 on cell growth and apoptosis. The effects of D395 and carfilzomib on serum enzyme activity, echocardiography features, cardiomyocyte morphology, and hERG channels were also compared. In our study, D395 was highly cytotoxic to MM cell lines and primary MM cells but not normal cells, and it was well tolerated in vivo. Similar to carfilzomib, D395 inhibited osteoclast differentiation in a dose-dependent manner. In particular, D395 exhibited lower cardiotoxicity than carfilzomib in all experiments. In conclusion, D395 is a novel irreversible proteasome inhibitor that has remarkable anti-MM activity and mild cardiotoxicity in vitro and in vivo.

Ixazomib: an oral proteasome inhibitor for the treatment of multiple myeloma

2015 ◽  
Vol 4 (1) ◽  
pp. 105-113 ◽  
Author(s):  
Neil Shah ◽  
Noa Biran ◽  
David H Vesole
Keyword(s):  
Multiple Myeloma ◽  
Proteasome Inhibitor

scholarly journals Nelfinavir Overcomes Proteasome Inhibitor Resistance in Multiple Myeloma By Modulating Membrane Lipid Bilayer Composition and Fluidity

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 11-11
Author(s):  
Andrej Besse ◽  
Lenka Besse ◽  
Sara C. Stolze ◽  
Amin Sobh ◽  
Esther A. Zaal ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Membrane Fluidity ◽  
Active Site ◽  
Proteasome Inhibitor ◽  
Membrane Lipid ◽  
Clinical Activity ◽  
Anti Cancer ◽  
Reporter Systems ◽  
Target Activity ◽  
Cancer Activity

INTRODUCTION Nelfinavir is a highly lipophilic, first generation HIV-protease inhibitor (HIV-PI) approved for HIV treatment. It has largely been replaced by next-generation HIV-PI with increased specificity and efficacy for HIV therapy, partly reflecting the significant rate of the off-target activity of nelfinavir. Increasing preclinical and clinical evidence shows that nelfinavir has broad anti-cancer activity as a single agent and in combination, potentially related to its off-target activity in mammalian cells. Nelfinavir is particularly effective in the treatment of proteasome inhibitor-refractory multiple myeloma (MM), where the combination of nelfinavir+bortezomib+dexamethasone yielded an overall response rate (ORR, PR or better) > 65% in a Phase II clinical trial. The targets and molecular mechanism of action of nelfinavir in MM are unknown. This hampers both, a rational clinical repositioning and development of nelfinavir as antineoplastic drug, as well as the design, synthesis and testing of next generation nelfinavir-like compounds with optimized antineoplastic activity and improved specificity or pharmacologic properties. We therefore aimed to take an unbiased target-identification approach to identify molecular targets of nelfinavir in human malignant cells and link them to cell biological processes and mechanisms that mediate sensitivity or resistance to nelfinavir treatment. METHODS Proteome-wide affinity-purification of targets binding the nelfinavir active site was combined with genome-wide CRISPR/Cas9-based screening to identify protein partners interacting with nelfinavir and candidate genetic contributors affecting nelfinavir cytotoxicity. Multiple intracellular reporter systems including RUSH system, ATP/ADP constructs; FRAP microscopy, Seahorse measurements, flow cytometry, qPCR, metabolic labelling, lipidomics and viability assays were used to dissect functional alterations in pathways related to nelfinavir targets. RESULTS We identified a common set of proteins interacting specifically with the active site of nelfinavir. These proteins are embedded in intracellular, lipid-rich membranes of mitochondria (VDAC1,2,3, ANT2), endoplasmic reticulum (BCAP31, CANX, SRPRB) and nuclear envelope (PGRMC2) and are consistent across multiple cancer cell types. ADIPOR2, a key regulator gene of membrane lipid fluidity, was identified as a key nelfinavir resistance gene, while genes involved in fatty acids (FAs) and cholesterol metabolism, vesicular trafficking and mitochondria biogenesis are candidate sensitivity genes. We further show that via binding to proteins in lipid-rich membranes nelfinavir affects membrane composition and reduces membrane fluidity, leading to induction of FAs synthesis and the unfolded protein response (UPR). Via its structural interference with membrane fluidity, nelfinavir impairs the function and mobility of a diverse set of membrane-associated proteins and processes, such as glucose flux and processing, mitochondria respiration, energy supply, transmembrane vesicular transport and ABCB1-mediated drug efflux, as we show in different reporter systems in live MM cells. These functional effects are prevented by addition of metabolically inert lipids to be incorporated in membranes, supporting a direct structural activity of nelfinavir. The adaptive biology of proteasome inhibitor (PI)-resistant myeloma relies on metabolic reprogramming and changes in lipid composition, drug export and down-modulation of the UPR. Modulation of membrane fluidity and depletion of FAs/cholesterol is synergistic with proteasome inhibitors in PI-resistant MM. Thus, the mechanism of action of nelfinavir perfectly matches with the biology of PI-resistant MM, serving as a molecular rational for its significant clinical activity. CONCLUSION We here demonstrate in vitro that the activity of nelfinavir against MM cells is triggered through changes in lipid metabolism and the fluidity of lipid-rich membranes. Pharmacologic targeting of membrane fluidity is a novel, potent mechanism to achieve anti-cancer activity, in particular against PI-refractory MM. This mechanism explains the clinical activity of nelfinavir in MM treatment as well as the key side effects of nelfinavir during antiretroviral therapy. Disclosures No relevant conflicts of interest to declare.

scholarly journals Daratumumab, Pomalidomide, and Dexamethasone (DPd) for the Treatment of Relapsed/Refractory Multiple Myeloma: A Single Institution Experience

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 5642-5642 ◽  
Author(s):  
Al-Ola Abdallah ◽  
Neil Dunavin ◽  
Brian McClune ◽  
Leyla Shune ◽  
Ajoy L. Dias ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Proteasome Inhibitor ◽  
Research Funding ◽  
Median Number ◽  
Autologous Stem Cell Transplant ◽  
Cell Transplant ◽  
Duration Of Treatment ◽  
Effective Treatment Option ◽  
Refractory Multiple Myeloma ◽  
Overall Response

Abstract Background: Daratumumab triplet regimens containing dexamethasone and lenalidomide or bortezomib are an effective treatment option for patients with relapsed/refractory multiple myeloma (RRMM). Daratumumab was recently FDA-approved in combination with the second-generation immunomodulatory drug, pomalidomide, and dexamethasone based (DPd) on results of the EQUULEUS study where overall response rates (ORR) of 60% were seen. The goal of this retrospective study was to analyze clinical outcomes of the DPd triplet regimen in either a daratumumab and pomalidomide naïve or refractory population of heavily pretreated RRMM patients at our institution. Methods: Thirty-two patients with RRMM treated with DPd at the University of Kansas Health System between November 2015 and July 2018 were included in our analysis. DPd consisted of 28-day cycles of daratumumab 16 mg/kg intravenously (weekly for cycles 1 and 2, every 2 weeks for cycles 3-6, and every 4 weeks thereafter until disease progression); pomalidomide 4 mg orally (PO)on Days 1-21 and adjusted for cytopenia or toxicities; and dexamethasone 40 mg PO weekly adjusted based on tolerance. based on age. Responses were evaluated using IMWG criteria. Patient characteristics, disease course, and outcomes were summarized with descriptive statistics. Kaplan-Meier analyses were used to estimate progression-free (PFS) and overall survival (OS). Results:The median age was 64 years (range 44-83). Twenty-three patients (72%) had IgG isotype, 11 patients (34 %) had ISS stage III disease at diagnosis, 13 patients (41%) had high risk cytogenetics, and 13 patients (41%) had extramedullary disease. Median number of previous lines of therapy was 4 (1-9). Twenty-two patients (69%) received ≥3 prior therapies. Twenty-three patients (72%) were proteasome inhibitor refractory, 28 patients (88%) were immunomodulator refractory, 9 patients (28%) were daratumumab refractory, and 3 patients (15%) were double refractory to daratumumab and pomalidomide. Twenty-eight patients (88%) had received autologous stem cell transplant (ASCT) prior to DPd; 12 patients (38%) had ≥2 prior transplants. Median number of DPd cycles received was 6 (2-30) and the median duration of treatment was 5 months (2-30). At a median follow-up of 8.4 months (range: 2-29), the overall response rate (ORR) for all patients was 72% which compares favorably to the ORR of 60% in the EQUULEUS study. However, about half of the responses were partial responses (PR) (47%). The ORR rate for those who were refractory to either pomalidomide or daratumumab was 65%. The PFS was 8.3 months, while the median OS was not reached. Conclusion: DPd was recently approved for the treatment of RRMM. Our ORR compares favorably to the EQUULEUS study, however about half of responses were partial responses or better. Surprisingly, our analysis shows an impressive ORR in patients with previous exposure to proteasome inhibitor and immunomodulatory therapies in RRMM population, suggesting a benefit of DPd even in patients who received prior pomalidomide or daratumumab. Disclosures McGuirk: Astellas Pharma: Research Funding; Gamida Cell: Research Funding; Novartis Pharmaceuticals Corporation: Honoraria, Other: speaker, Research Funding; Pluristem Ltd: Research Funding; Kite Pharma: Honoraria, Other: travel accommodations, expenses, speaker ; Fresenius Biotech: Research Funding; Bellicum Pharmaceuticals: Research Funding. Ganguly:Daiichi Sankyo: Research Funding; Janssen: Consultancy; Amgen: Consultancy; Seattle Genetics: Speakers Bureau.

scholarly journals Synergistic activity of the proteasome inhibitor PS-341 with non-myeloablative 153-Sm-EDTMP skeletally targeted radiotherapy in an orthotopic model of multiple myeloma

Blood ◽  
2006 ◽  
Vol 107 (10) ◽  
pp. 4063-4070 ◽  
Author(s):  
Apollina Goel ◽  
Angela Dispenzieri ◽  
Susan M. Geyer ◽  
Suzanne Greiner ◽  
Kah-Whye Peng ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Proteasome Inhibitor ◽  
In Vivo Model ◽  
Synergistic Activity ◽  
Mineral Density ◽  
Orthotopic Model ◽  
Targeted Radiotherapy ◽  
Myeloma Cells ◽  
Cell Counts

Multiple myeloma is a highly radiosensitive skeletal malignancy, but bone-seeking radionuclides have not yet found their place in disease management. We previously reported that the proteasome inhibitor PS-341 selectively sensitizes myeloma cells to the lethal effects of ionizing radiation. To extend these observations to an in vivo model, we combined PS-341 with the bone-seeking radionuclide 153-Sm-EDTMP. In vitro clonogenic assays demonstrated synergistic killing of myeloma cells exposed to both PS-341 and 153-Sm-EDTMP. Using the orthotopic, syngeneic 5TGM1 myeloma model, the median survivals of mice treated with saline, 2 doses of PS-341 (0.5 mg/kg), or a single nonmyeloablative dose of 153-Sm-EDTMP (22.5 MBq) were 21, 22, and 28 days, respectively. In contrast, mice treated with combination therapy comprising 2 doses of PS-341 (0.5 mg/kg), 1 day prior to and 1 day following 153-Sm-EDTMP (22.5 MBq) showed a significantly prolonged median survival of 49 days (P < .001). In addition to prolonged survival, this treatment combination yielded reduced clonogenicity of bone marrow–resident 5TGM1 cells, reduced serum myeloma–associated paraprotein levels, and better preservation of bone mineral density. Myelosuppression, determined by peripheral blood cell counts and clonogenicity assays of hematopoietic progenitors, did not differ between animals treated with 153-Sm-EDTMP alone versus those treated with the combination of PS-341 plus 153-Sm-EDTMP. PS-341 is a potent, selective in vivo radiosensitizer that may substantially affect the efficacy of skeletal-targeted radiotherapy in multiple myeloma.

scholarly journals Prospective Study of Cardiac Events During Proteasome Inhibitor Therapy for Relapsed Multiple Myeloma

2019 ◽  
Vol 37 (22) ◽  
pp. 1946-1955 ◽  
Author(s):  
Robert F. Cornell ◽  
Bonnie Ky ◽  
Brendan M. Weiss ◽  
Cherie N. Dahm ◽  
Deepak K. Gupta ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Natriuretic Peptides ◽  
Odds Ratio ◽  
Proteasome Inhibitor ◽  
Troponin I ◽  
Progression Free Survival ◽  
Cardiac Biomarkers ◽  
Cardiac Events ◽  
Increased Risk ◽  
Grade 3

PURPOSE Cardiovascular adverse events (CVAEs) can occur during proteasome inhibitor (PI) therapy. We conducted a prospective, observational, multi-institutional study to define risk factors and outcomes in patients with multiple myeloma (MM) receiving PIs. PATIENTS AND METHODS Patients with relapsed MM initiating carfilzomib- or bortezomib-based therapy underwent baseline assessments and repeated assessments at regular intervals over 6 months, including cardiac biomarkers (troponin I or T, brain natriuretic peptide [BNP], and N-terminal proBNP), ECG, and echocardiography. Monitoring occurred over 18 months for development of CVAEs. RESULTS Of 95 patients enrolled, 65 received carfilzomib and 30 received bortezomib, with median 25 months of follow-up. Sixty-four CVAEs occurred, with 55% grade 3 or greater in severity. CVAEs occurred in 51% of patients treated with carfilzomib and 17% of those treated with bortezomib ( P = .002). Median time to first CVAE from treatment start was 31 days, and 86% occurred within the first 3 months. Patients receiving carfilzomib-based therapy with a baseline elevated BNP level higher than 100 pg/mL or N-terminal proBNP level higher than 125 pg/mL had increased risk for CVAE (odds ratio, 10.8; P < .001). Elevated natriuretic peptides occurring mid–first cycle of treatment with carfilzomib were associated with a substantially higher risk of CVAEs (odds ratio, 36.0; P < .001). Patients who experienced a CVAE had inferior progression-free survival (log-rank P = .01) and overall survival (log-rank P < .001). PI therapy was safely resumed in 89% of patients, although 41% required chemotherapy modifications. CONCLUSION CVAEs are common during PI therapy for relapsed MM, especially with carfilzomib, particularly within the first 3 months of therapy. CVAEs were associated with worse overall outcomes, but usually, discontinuation of therapy was not required. Natriuretic peptides were highly predictive of CVAEs; however, validation of this finding is necessary before uniform incorporation into the routine management of patients receiving carfilzomib.

Sign in / Sign up

Export Citation Format

Share Document