Abstract 1996
Background
Adult T-cell leukemia/lymphoma (ATL) is a malignancy of mature T lymphocytes induced by human T-cell leukemia virus-1, and has a poor outcome. New molecular targets for the prevention and treatment of ATL are urgently needed. We previously reported that Sirtuin 1, a nicotinamide adenine dinucleotide (NAD+)-dependent histone/protein deacetylase, is highly expressed in primary acute-type ATL cells. NAD+ biosynthesis via nicotinamide phosphoribosyltransferase (NAMPT) modulates Sirtuin 1 activity. Here, we examined the expression and effects of inhibiting NAMPT, a rate-limiting.
Methods
Peripheral blood mononuclear cells from ATL patients were carried out in accordance with the guidelines of the Committees for Ethical Review of Research involving Human Subjects at Kagoshima University Hospital. Cell viability was evaluated in the S1T cell line derived from an ATL patient, MT-2 cell line derived from normal human leukocytes transformed by leukemic T-cells from an ATL patient, and primary ATL cells. Animal experiments were approved by the Animal Care and Use Committee of Rakuno Gakuen University in accordance with the Guide for the Care and Use of Laboratory Animals.
Results
Peripheral blood mononuclear cells from acute-type ATL patients expressed significantly higher NAMPT protein levels than cells from healthy controls. FK866, a NAMPT inhibitor, induced apoptosis in fresh ATL cells ex vivo and HTLV-1-infected T-cell lines in vitro, which was accompanied by NAD+ depletion, activation of caspases, DNA fragmentation, and disruption of mitochondrial transmembrane potential. A pan-caspase inhibitor failed to prevent the FK866-induced cell death, while FK866 increased endonuclease G, a caspase-independent cell death mediator. Intriguingly, FK866 activated autophagy, revealed by increased LC3-II protein levels and autophagic flux. Thus, FK866 simultaneously activated apoptosis and autophagy. Finally, FK866 treatment markedly decreased human ATL tumor xenograft growth in immunodeficient mice.
Conclusions
These results demonstrate that NAMPT inhibition induces autophagy and caspase-dependent and -independent cell death in ATL cells, suggesting a novel therapeutic strategy for patients with this fatal disease.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
5995 - Invasive fungal diseases caused by rare pathogens in patients after hematopoietic stem cell transplantation (HSCT) & chemotherapy
Presenter: Yuliya Rogacheva
Session: Poster Display session 1
Resources:
Abstract
2961 - Safety and pharmacokinetics of novel CXCR4 antagonist YF-H-2015005 in the mobilization of hematopoietic stem cells in patients with non-Hodgkin's lymphoma
Presenter: Weiping Liu
Session: Poster Display session 1
Resources:
Abstract
5771 - Chemotherapy associated Hyponatremia in Hematological Malignancies: A retrospective study of 189 patients treated in a single medical center
Presenter: Vadim Lesan
Session: Poster Display session 1
Resources:
Abstract
1165 - Risk factors for Bacteremia-Associated Mortality of Aeromona sobria in Hematologic Malignancies
Presenter: Gabriel De la Cruz-Kú
Session: Poster Display session 1
Resources:
Abstract
5287 - Use of droplet digital polymerase chain reaction for detecting minimal residual disease: a prospective, multi-institutional study
Presenter: Hyunkyung Park
Session: Poster Display session 1
Resources:
Abstract
1886 - RUBIH2 — Use of NGS in haematological malignancies: from real world data to national recommendations, an innovative program to evaluate the impact of healthcare technology on patient care
Presenter: Severine Coquerelle
Session: Poster Display session 1
Resources:
Abstract
1940 - Outcomes of chronic myeloid leukemia with T315I mutation in the absence of targeted therapy or hematopoietic stem cell transplantation
Presenter: Nageswara Palukuri
Session: Poster Display session 1
Resources:
Abstract
1946 - Is bone marrow examination indispensible in chronic myeloid Leukemia at diagnosis ?
Presenter: Nageswara Palukuri
Session: Poster Display session 1
Resources:
Abstract
1904 - Incidence of Imatinib Resistance in Chronic Myeloid Leukemia (CML) Patients: Experience from Resource Poor Centre of Eastern India
Presenter: Debmalya Bhattacharyya
Session: Poster Display session 1
Resources:
Abstract
3245 - BCR-ABL transcript variant’s significance in chronic myeloid leukemia in chronic phase: Institutional experience from a developing country
Presenter: Siva Prasad
Session: Poster Display session 1
Resources:
Abstract