Michel A Duchosal

University Hospital of Lausanne, Lausanne, Vaud, Switzerland

Are you Michel A Duchosal?

Claim your profile

Publications (81)475.93 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Pancreatic cancer (PC) is one of the most lethal human malignancies and a major health problem. Patients diagnosed with PC and treated with conventional approaches have an overall 5-year survival rate of less than 5%. Novel strategies are needed to treat this disease. Herein, we propose a combinatorial strategy that targets two unrelated metabolic enzymes overexpressed in PC cells: NAD(P)H:quinone oxidoreductase-1 (NQO1) and nicotinamide phosphoribosyl transferase (NAMPT) using β-lapachone (BL) and APO866, respectively. We show that BL tremendously enhances the antitumor activity of APO866 on various PC cell lines without affecting normal cells, in a PARP-1 dependent manner. The chemopotentiation of APO866 with BL was characterized by the following: (i) nicotinamide adenine dinucleotide (NAD) depletion; (ii) catalase (CAT) degradation; (iii) excessive H2O2 production; (iv) dramatic drop of mitochondrial membrane potential (MMP); and finally (v) autophagic-associated cell death. H2O2 production, loss of MMP and cell death (but not NAD depletion) were abrogated by exogenous supplementation with CAT or pharmacological or genetic inhibition of PARP-1. Our data demonstrates that the combination of a non-lethal dose of BL and low dose of APO866 optimizes significantly cell death on various PC lines over both compounds given separately and open new and promising combination in PC therapy. Copyright © 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.
    Biochimie 07/2015; DOI:10.1016/j.biochi.2015.07.012 · 3.12 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The availability of drugs such as thalidomide, bortezomib and lenalidomide changed the landscape in myeloma treatment and has extended the median survival up to 10 years with a substantial improvement in quality of life. This development prompted a Swiss expert panel to re-evaluate the current status and formulate updated clinical recommendations for the diagnosis and treatment of plasma cell myeloma. These recommendations should help clinicians in their decision making to achieve the best outcome based on currently available data.
    Swiss medical weekly: official journal of the Swiss Society of Infectious Diseases, the Swiss Society of Internal Medicine, the Swiss Society of Pneumology 02/2015; 145. DOI:10.4414/smw.2015.14100 · 1.88 Impact Factor
  • Cancer Chemotherapy and Pharmacology 10/2014; · 2.57 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: CD19 is a B cell lineage specific surface receptor whose broad expression, from pro-B cells to early plasma cells, makes it an attractive target for the immunotherapy of B cell malignancies. In this study we present the generation of a novel humanized anti-CD19 monoclonal antibody (mAb), GBR 401, and investigate its therapeutic potential on human B cell malignancies. GBR 401 was partially defucosylated in order to enhance its cytotoxic function. We analyzed the in vitro depleting effects of GBR 401 against B cell lines and primary malignant B cells from patients in the presence or in absence of purified NK cells isolated from healthy donors. In vivo, the antibody dependent cellular cytotoxicity (ADCC) efficacy of GBR 401 was assessed in a B cell depletion model consisting of SCID mice injected with healthy human donor PBMC, and a malignant B cell depletion model where SCID mice are xenografted with both primary human B-CLL tumors and heterologous human NK cells. Furthermore, the anti-tumor activity of GBR 401 was also evaluated in a xenochimeric mouse model of human Burkitt lymphoma using mice xenografted intravenously with Raji cells. Pharmacological inhibition tests were used to characterize the mechanism of the cell death induced by GBR 401. GBR 401 exerts a potent in vitro and in vivo cytotoxic activity against primary samples from patients representing various B-cell malignancies. GBR 401 elicits a markedly higher level of ADCC on primary malignant B cells when compared to fucosylated similar mAb and to Rituximab, the current anti-CD20 mAb standard immunotherapeutic treatment for B cell malignancies, showing killing at 500 times lower concentrations. Of interest, GBR 401 also exhibits a potent direct killing effect in different malignant B cell lines that involves homotypic aggregation mediated by actin relocalization. These results contribute to consolidate clinical interest in developing GBR 401 for treatment of hematopoietic B cell malignancies, particularly for patients refractory to anti-CD20 mAb therapies.
    Journal of Hematology & Oncology 04/2014; 7(1):33. DOI:10.1186/1756-8722-7-33 · 4.93 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: APO866, an inhibitor of NAD biosynthesis, exhibits potent antitumor properties in various malignancies. Recently, it has been shown that APO866 induces apoptosis and autophagy in human hematological cancer cells, but the role of autophagy in APO866-induced cell death remains unclear. Here, we report studies on the molecular mechanisms underlying APO866-induced cell death with emphasis on autophagy. Treatment of leukemia and lymphoma cells with APO866 induced both autophagy, as evidenced by an increase in autophagosome formation and in SQSTM1/p62 degradation, but also increased caspase activation as revealed by CASP3/caspase 3 cleavage. As an underlying mechanism, APO866-mediated autophagy was found to deplete CAT/catalase, a reactive oxygen species (ROS) scavenger, thus promoting ROS production and cell death. Inhibition of autophagy by ATG5 or ATG7 silencing prevented CAT degradation, ROS production, caspase activation, and APO866-induced cell death. Finally, supplementation with exogenous CAT also abolished APO866 cytotoxic activity. Altogether, our results indicated that autophagy is essential for APO866 cytotoxic activity on cells from hematological malignancies and also indicate an autophagy-dependent CAT degradation, a novel mechanism for APO866-mediated cell killing. Autophagy-modulating approaches could be a new way to enhance the antitumor activity of APO866 and related agents.
    Autophagy 01/2014; 10(4). DOI:10.4161/auto.27722 · 11.42 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Research in autophagy continues to accelerate,(1) and as a result many new scientists are entering the field. Accordingly, it is important to establish a standard set of criteria for monitoring macroautophagy in different organisms. Recent reviews have described the range of assays that have been used for this purpose.(2,3) There are many useful and convenient methods that can be used to monitor macroautophagy in yeast, but relatively few in other model systems, and there is much confusion regarding acceptable methods to measure macroautophagy in higher eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers of autophagosomes versus those that measure flux through the autophagy pathway; thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from fully functional autophagy that includes delivery to, and degradation within, lysosomes (in most higher eukaryotes) or the vacuole (in plants and fungi). Here, we present a set of guidelines for the selection and interpretation of the methods that can be used by investigators who are attempting to examine macroautophagy and related processes, as well as by reviewers who need to provide realistic and reasonable critiques of papers that investigate these processes. This set of guidelines is not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to verify an autophagic response.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Abstract APO866 is an inhibitor of NAD biosynthesis which exhibits potent anti-lymphoma activity. Rituximab (RTX), an anti-CD20 antibody, kills lymphoma cells by direct apoptosis and antibody- and complement dependent cell-mediated cytotoxicities and has clinical efficacy in non-Hodgkin cell lymphomas. In the present study, we evaluate whether RTX could potentiate APO866-induced human B-lymphoma cell death and shed light on death-mediated mechanisms associated with this drug combination. We found that RTX significantly increases APO866-induced death in lymphoma cells from patients and lines. Mechanisms include enhancement of autophagy-mediated cell death, activation of caspase 3, exacerbation of mitochondria depolarization but not increase of ROS production when compared with those induced by each drug alone. In vivo, combined administration of APO866 with RTX in laboratory model of human aggressive lymphoma significantly decreased tumor burden and prolonged survival over single agent treatment. Our study demonstrates that combination of RTX and APO866 optimizes B cell lymphoma apoptosis and therapeutic efficacy over both compounds administered separately.
    Leukemia & lymphoma 11/2013; 55(9). DOI:10.3109/10428194.2013.869325 · 2.89 Impact Factor
  • Anne Cairoli · Nicolas Ketterer · Stefano Barelli · Michel A Duchosal
    [Show abstract] [Hide abstract]
    ABSTRACT: ABSTRACT We report here long term outcome of autologous stem cell transplantation in peripheral T-cell lymphomas (PTCL). Forty-three consecutive patients with PTCL diagnosed between 2000-2011 were treated with high-dose chemotherapy (HDCT) and autologous stem cell transplantation (ASCT) in our center. Diagnoses included PTCL-not otherwise specified (n=19), anaplastic large cell lymphoma (n=11), angioimmunoblastic T-cell lymphoma (n=5), enteropathy-associated T-cell lymphoma (n=5) and other rare subtypes (n=3). Thirty-six patients, with a median age of 50 years (range 22-65), were transplanted in first response and seven after relapse. After a median follow-up of 63 months, estimated overall survival at 12-years was 40%, progression free survival at 12-years was 34% and event free survival at 12-years was 30%. On univariate analysis, age less than 50-years and no B-symptoms at diagnosis were significantly associated with prolonged overall- and progression free-survival. HDCT/ASCT for peripheral T-cell lymphoma can lead to long-term survival for patients responding to induction chemotherapy.
    Leukemia & lymphoma 10/2013; 55(8). DOI:10.3109/10428194.2013.852666 · 2.89 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Purpose This study assessed whether a cycle of “routine” therapeutic drug monitoring (TDM) for imatinib dosage individualization, targeting an imatinib trough plasma concentration (C min) of 1,000 ng/ml (tolerance: 750–1,500 ng/ml), could improve clinical outcomes in chronic myelogenous leukemia (CML) patients, compared with TDM use only in case of problems (“rescue” TDM). Methods Imatinib concentration monitoring evaluation was a multicenter randomized controlled trial including adult patients in chronic or accelerated phase CML receiving imatinib since less than 5 years. Patients were allocated 1:1 to “routine TDM” or “rescue TDM.” The primary endpoint was a combined outcome (failure- and toxicity-free survival with continuation on imatinib) over 1-year follow-up, analyzed in intention-to-treat (ISRCTN31181395). Results Among 56 patients (55 evaluable), 14/27 (52 %) receiving “routine TDM” remained event-free versus 16/28 (57 %) “rescue TDM” controls (P = 0.69). In the “routine TDM” arm, dosage recommendations were correctly adopted in 14 patients (median C min: 895 ng/ml), who had fewer unfavorable events (28 %) than the 13 not receiving the advised dosage (77 %; P = 0.03; median C min: 648 ng/ml). Conclusions This first target concentration intervention trial could not formally demonstrate a benefit of “routine TDM” because of small patient number and surprisingly limited prescriber’s adherence to dosage recommendations. Favorable outcomes were, however, found in patients actually elected for target dosing. This study thus shows first prospective indication for TDM being a useful tool to guide drug dosage and shift decisions. The study design and analysis provide an interesting paradigm for future randomized TDM trials on targeted anticancer agents.
    Clinical Therapeutics 08/2013; 35(8):e6. DOI:10.1007/s00280-014-2599-1 · 2.59 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Haematopoietic stem cell transplantation (HSCT) is a highly specialised procedure used to treat malignancies of the lymphohaematopoietic system as well as some acquired and inherited disorders of the blood. This analysis by the Swiss Blood Stem Cell Transplantation Group, based on data from 2008-2011, describes, treatment rates in Switzerland for specific indications and compares this with data from Germany, France, Italy and the Netherlands, corrected for the size of the population. Differences in transplant rates, in rates for particular indications, and in the use of specific transplant technologies such as use of unrelated donors, use of cord blood or mismatched family donors are described. These data are put in correlation with donor availability from international registries and with number of transplant teams and number of procedures per team all corrected for population size.
    Schweizerische medizinische Wochenschrift 02/2013; 143. DOI:10.4414/smw.2013.13757 · 1.88 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Enteropathy-associated T-cell lymphoma (EATL) is a rare subtype of peripheral T-cell lymphomas with a poor prognosis. Autologous stem cell transplantation (ASCT) was retrospectively evaluated as consolidation or salvage strategy for EATL. The analysis included 44 patients who received ASCT for EATL between 2000 and 2010. Thirty-one patients (70 %) were in first complete or partial remission at the time of ASCT. With a median follow-up of 46 months, relapse incidence, progression-free survival and overall survival were 39%, 54% and 59% at four years, respectively with only one relapse occurring beyond 18 months post-transplant. There was a trend for better survival in patients transplanted in first complete or partial remission at four years (66% vs. 36%, p=0.062). ASCT is feasible in selected patients with EATL and can yield durable disease control in a significant proportion of the patients.
    Blood 01/2013; 121(13). DOI:10.1182/blood-2012-11-466839 · 10.43 Impact Factor
  • Haematologica 08/2012; 97(12). DOI:10.3324/haematol.2012.065151 · 5.87 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure flux through the autophagy pathway (i.e., the complete process);5,6 thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.
    Autophagy 04/2012; 8(4). · 11.42 Impact Factor
  • Source
    Autophagy 04/2012; 4454(8):445-544. · 11.42 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.
    Autophagy 04/2012; 8(4):1-100. DOI:10.4161/auto.19496 · 11.42 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.
    Autophagy 04/2012; 8(4):445-544. · 11.42 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.
    Autophagy 04/2012; 8(4):445. · 11.42 Impact Factor
  • Source
    Autophagy 01/2012; 4454(8):445-544. · 11.42 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: There remains a clear need for effective tumor cell purging in autologous stem cell transplantation (ASCT) where residual malignant cells within the autograft contribute to disease relapse. Here we propose the use of a novel Fas agonist with potent pro-apoptotic activity, termed MegaFasL, as an effective ex-vivo purging agent. MegaFasL selectively kills hematological cancer cells from lymphomas and leukemias and prevents tumor development at concentrations that do not reduce the functional capacity of human hematopoietic stem/progenitor cells both in in vitro and in in vivo transplantation models. These findings highlight the potential use of MegaFasL as an ex-vivo purging agent in ASCT.
    Blood Cancer Journal 12/2011; 1(12):e47. DOI:10.1038/bcj.2011.47 · 2.88 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: New derivatives of 1,4-dideoxy-1,4-imino-D-ribitol have been prepared and evaluated for their cytotoxicity on solid and haematological malignancies. 1,4-Dideoxy-5-O-[(9Z)-octadec-9-en-1-yl]-1,4-imino-D-ribitol (13, IC(50) ∼2 μM) and its C(18)-analogues (IC(50) <10 μM) are cytotoxic toward SKBR3 (breast cancer) cells. 13 also inhibits (IC(50) ∼8 μM) growth of JURKAT cells.
    Bioorganic & medicinal chemistry 07/2011; 19(24):7720-7. DOI:10.1016/j.bmc.2011.07.053 · 2.95 Impact Factor

Publication Stats

3k Citations
475.93 Total Impact Points

Institutions

  • 1996–2015
    • University Hospital of Lausanne
      • • Service d'hématologie
      • • Département de médecine
      Lausanne, Vaud, Switzerland
  • 2012
    • University of Michigan
      • Life Sciences Institute
      Ann Arbor, MI, United States
  • 2008–2009
    • University of Lausanne
      Lausanne, Vaud, Switzerland
  • 1987–1993
    • The Scripps Research Institute
      La Jolla, California, United States