The NOTCH1/CD44 axis drives pathogenesis in a T cell acute lymphoblastic leukemia model
Marina García-Peydró, … , Francisco Sánchez-Madrid, María L. Toribio
Marina García-Peydró, … , Francisco Sánchez-Madrid, María L. Toribio
Published May 21, 2018
Citation Information: J Clin Invest. 2018;128(7):2802-2818. https://doi.org/10.1172/JCI92981.
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Research Article Hematology Oncology

The NOTCH1/CD44 axis drives pathogenesis in a T cell acute lymphoblastic leukemia model

Abstract

NOTCH1 is a prevalent signaling pathway in T cell acute lymphoblastic leukemia (T-ALL), but crucial NOTCH1 downstream signals and target genes contributing to T-ALL pathogenesis cannot be retrospectively analyzed in patients and thus remain ill defined. This information is clinically relevant, as initiating lesions that lead to cell transformation and leukemia-initiating cell (LIC) activity are promising therapeutic targets against the major hurdle of T-ALL relapse. Here, we describe the generation in vivo of a human T cell leukemia that recapitulates T-ALL in patients, which arises de novo in immunodeficient mice reconstituted with human hematopoietic progenitors ectopically expressing active NOTCH1. This T-ALL model allowed us to identify CD44 as a direct NOTCH1 transcriptional target and to recognize CD44 overexpression as an early hallmark of preleukemic cells that engraft the BM and finally develop a clonal transplantable T-ALL that infiltrates lymphoid organs and brain. Notably, CD44 is shown to support crucial BM niche interactions necessary for LIC activity of human T-ALL xenografts and disease progression, highlighting the importance of the NOTCH1/CD44 axis in T-ALL pathogenesis. The observed therapeutic benefit of anti-CD44 antibody administration in xenotransplanted mice holds great promise for therapeutic purposes against T-ALL relapse.

Authors

Marina García-Peydró, Patricia Fuentes, Marta Mosquera, María J. García-León, Juan Alcain, Antonio Rodríguez, Purificación García de Miguel, Pablo Menéndez, Kees Weijer, Hergen Spits, David T. Scadden, Carlos Cuesta-Mateos, Cecilia Muñoz-Calleja, Francisco Sánchez-Madrid, María L. Toribio

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Figure 3

CD44 upregulation is an early hallmark of aberrant NOTCH1 signaling and ectopic T cell development.

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CD44 upregulation is an early hallmark of aberrant NOTCH1 signaling and ...
(A and B) GFP reporter and CD44 expression of ICN1+CD45+ human cells engrafting the thymus or BM of RAG-2–/– × γc–/– mice transplanted with either ETPs (A) or CB HSPCs (B) transduced with ICN1 and GFP. Cells were obtained at 2 to 6 and 9 weeks after transplant, respectively. Mean fluorescence intensity (MFI) combined results from 6 independent experiments, with a total of 3 to 30 mice per group, are shown. (C) Representative FACS phenotype of T-lineage cell subsets derived from ICN1-transduced human ETPs in the BM of RAG-2–/– × γc–/– mice shown in A at 13 and 21 days after transplant (CD4ISP, CD4+CD3-; DP TCR-αβ, CD4+CD8+CD3+TCR-αβ+; DP pre-TCR, CD4+CD8+CD3loTCR-αβ–). (D) CD44 expression levels of human CD4 ISP, DP pre-TCR, and DP TCR-αβ cells generated at 2, 3, and 6 weeks after transplant, respectively, in the BM and thymus of mice shown in A or at 9 weeks after transplant in the BM and thymus of mice shown in B. CD44 expression of control cells generated from either ETPs or CB HSPCs transduced with GFP (GFP+) in the thymus and of human B cells generated in the BM from GFP+ HSPCs is also shown. MFI ± SEM combined results from 6 (ETPs) and 3 (HSPCs) independent experiments, with a total of 3 to 9 mice per group are shown. Data were corrected by the FDR method. (E and F) Relative mRNA expression of CD44, HES1, IL7R, and IL2RG genes analyzed by qPCR and normalized to GAPDH in GFP- or ICN1-transduced human ETPs after 36 hours of transduction (C) or in DP thymocytes and BM ectopic DP cells derived from GFP- or ICN1-transduced human ETPs at 4 weeks after transplant. Data are shown as mean ± SEM of triplicates (n = 5). **P < 0.01; ***P < 0.001; ****P < 0.0001.