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
4883 - A New Population Model Validated Pharmacokinetic Similarity of HLX01 and Rituximab in B-Cell Lymphoma
Presenter: Yuankai Shi
Session: Poster Display session 1
Resources:
Abstract
4908 - Efficacy of salvage therapy in the treatment of Helicobacter pylori-positive gastric low-grade mucosa-associated lymphoid tissue lymphoma
Presenter: Sung-Nam Lim
Session: Poster Display session 1
Resources:
Abstract
2360 - Mutational analysis of extranodal marginal zone lymphoma using next generation sequencing
Presenter: Seok Jae Huh
Session: Poster Display session 1
Resources:
Abstract
2430 - Clinical features, treatment and outcomes of colon and rectum mucosa-associated lymphoid tissue (MALT) lymphoma: Literature reviews published in English between 1993 and 2017
Presenter: Jeong Yeon Kim
Session: Poster Display session 1
Resources:
Abstract
4654 - Splenic marginal zone lymphoma: clinical characteristics and prognostic factors in a series of 52 patients
Presenter: Guldane Cengiz Seval
Session: Poster Display session 1
Resources:
Abstract
1732 - Safety and efficacy of Bendamustine and Rituximab (BR) regimen in Indian Chronic Lymphocytic Leukemia patients
Presenter: Ajay Gogia
Session: Poster Display session 1
Resources:
Abstract
5784 - N-terminal B-type natriuretic peptide (NT-proBNP) as an independed prognostic marker for patients with newly diagnosed multiple myeloma complicated by dialysis-dependent renal failure
Presenter: Sergey Semochkin
Session: Poster Display session 1
Resources:
Abstract
836 - The first-line effect of Bortezomib-based Therapy on Clinical Outcomes for Taiwanese Patients with multiple myeloma
Presenter: Ching-Liang Ho
Session: Poster Display session 1
Resources:
Abstract
2085 - Impact of Donor Lymphocyte Infusion in Relapsing Myeloid Neoplasms Post Allogeneic Hematopoietic Stem Cell Transplantation
Presenter: Hanafy Hafez
Session: Poster Display session 1
Resources:
Abstract
6079 - Invasive fungal diseases in patients with Hodgkin’s lymphoma before and after allogeneic hematopoietic stem cell transplantation
Presenter: Marina Popova
Session: Poster Display session 1
Resources:
Abstract