1. Academic Validation
  2. Spleen plays a major role in DLL4-driven acute T-cell lymphoblastic leukemia

Spleen plays a major role in DLL4-driven acute T-cell lymphoblastic leukemia

  • Theranostics. 2021 Jan 1;11(4):1594-1608. doi: 10.7150/thno.48067.
Huizhong Xiong 1 2 3 Maicol Mancini 4 Michael Gobert 1 Shiqian Shen 1 5 Glaucia C Furtado 6 Sergio A Lira 6 Christopher N Parkhurst 1 Veronique Garambois 4 Muriel Brengues 4 Carlos E Tadokoro 1 7 Thomas Trimarchi 8 Gonzalo Gómez-López 9 Amartya Singh 10 Hossein Khiabanian 10 11 Sonia Minuzzo 12 Stefano Indraccolo 13 Camille Lobry 8 14 Iannis Aifantis 8 15 Daniel Herranz 10 16 Juan J Lafaille 1 8 Antonio Maraver 4
Affiliations

Affiliations

  • 1 Kimmel Center for Biology and Medicine at the Skirball Institute, New York University School of Medicine, New York, NY 10016, USA.
  • 2 The Sackler Institute of Graduate Biomedical Sciences, New York University School of Medicine, New York, NY 10016, USA.
  • 3 Current address: Genentech, South San Francisco, CA, 94080.
  • 4 Institut de Recherche en Cancérologie de Montpellier (IRCM), Université de Montpellier, Institut Régional du Cancer de Montpellier (ICM), Montpellier, 34298, Cedex 5, France.
  • 5 Current address: Department of Anesthesia, Critical Care and Pain Medicine Massachusetts General Hospital, Boston, MA 02114, USA.
  • 6 Immunology Institute, Mount Sinai School of Medicine, New York, NY 10029, USA.
  • 7 Current address: Universidade Vila Velha, Vila Velha, 29102-920, Brazil.
  • 8 Department of Pathology, New York University School of Medicine, New York, NY 10016, USA.
  • 9 Bioinformatics unit. Spanish National Cancer Research Center (CNIO). Madrid, Spain.
  • 10 Rutgers Cancer Institute of New Jersey, Rutgers University, New Brunswick, NJ, USA.
  • 11 Department of Pathology and Laboratory Medicine, Rutgers Robert Wood Johnson Medical School, Rutgers University, New Brunswick, NJ, USA.
  • 12 Department of Surgery, Oncology and Gastroenterology, University of Padova, Padova, Italy.
  • 13 Veneto Institute of Oncology IOV - IRCCS, Padova, Italy.
  • 14 Institut de Recherche Saint Louis, INSERM U944/CNRS UMR7212, Paris, 75010, France.
  • 15 Howard Hughes Medical Institute.
  • 16 Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, USA.
Abstract

The Notch pathway is highly active in almost all patients with T-cell acute lymphoblastic leukemia (T-ALL), but the implication of Notch ligands in T-ALL remains underexplored. Methods: We used a genetic mouse model of Notch ligand delta like 4 (DLL4)-driven T-ALL and performed thymectomies and splenectomies in those Animals. We also used several patient-derived T-ALL (PDTALL) models, including one with DLL4 expression on the membrane and we treated PDTALL cells in vitro and in vivo with demcizumab, a blocking antibody against human DLL4 currently being tested in clinical trials in patients with solid Cancer. Results: We show that surgical removal of the spleen abrogated T-ALL development in our preclinical DLL4-driven T-ALL mouse model. Mechanistically, we found that the spleen, and not the thymus, promoted the accumulation of circulating CD4+CD8+ T cells before T-ALL onset, suggesting that DLL4-driven T-ALL derives from these cells. Then, we identified a small subset of T-ALL patients showing higher levels of DLL4 expression. Moreover, in mice xenografted with a DLL4-positive PDTALL model, treatment with demcizumab had the same therapeutic effect as global Notch pathway inhibition using the potent γ-secretase Inhibitor dibenzazepine. This result demonstrates that, in this PDTALL model, Notch pathway activity depends on DLL4 signaling, thus validating our preclinical mouse model. Conclusion: DLL4 expression in human leukemic cells can be a source of Notch activity in T-ALL, and the spleen plays a major role in a genetic mouse model of DLL4-driven T-ALL.

Keywords

DLL4; Notch pathway; T-ALL; demcizumab; patient-derived xenografts.

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