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Haematologica 2019 Volume 104(10):2006-2016
Acute Myeloid Leukemia
Arrayed molecular barcoding identifies TNFSF13 as a positive regulator of acute myeloid leukemia-initiating cells
Marion Chapellier,1 Pablo Peña-Martínez,1 Ramprasad Ramakrishnan,1 Mia Eriksson,1 Mehrnaz Safaee Talkhoncheh,2 Christina Orsmark-Pietras,1 Henrik Lilljebjörn1, Carl Högberg,1 Anna Hagström-Andersson,1 Thoas Fioretos,1 Jonas Larsson,2 and Marcus Järås1
1Department of Clinical Genetics and 2Molecular Medicine and Gene Therapy, Lund Stem Cell Center, Lund University, Lund, Sweden
ABSTRACT
Dysregulation of cytokines in the bone marrow (BM) microenviron- ment promotes acute myeloid leukemia (AML) cell growth. Due to the complexity and low throughput of in vivo stem-cell based assays, studying the role of cytokines in the BM niche in a screening setting is challenging. Here, we developed an ex vivo cytokine screen using 11 arrayed molecular barcodes, allowing for a competitive in vivo readout of leukemia-initiating capacity. With this approach, we assessed the effect of 114 murine cytokines on MLL-AF9 AML mouse cells and identified the tumor necrosis factor ligand superfamily member 13 (TNFSF13) as a posi- tive regulator of leukemia-initiating cells. By using Tnfsf13-/- recipient mice, we confirmed that TNFSF13 supports leukemia initiation also under phys- iological conditions. TNFSF13 was secreted by normal myeloid cells but not by leukemia mouse cells, suggesting that mature myeloid BM cells support leukemia cells by secreting TNFSF13. TNFSF13 supported leukemia cell proliferation in an NF-kB-dependent manner by binding TNFRSF17 and suppressed apoptosis. Moreover, TNFSF13 supported the growth and sur- vival of several human myeloid leukemia cell lines, demonstrating that our findings translate to human disease. Taken together, using arrayed molecu- lar barcoding, we identified a previously unrecognized role of TNFSF13 as a positive regulator of AML-initiating cells. The arrayed barcoded screening methodology is not limited to cytokines and leukemia, but can be extended to other types of ex vivo screens, where a multiplexed in vivo read-out of stem cell functionality is needed.
Introduction
Acute myeloid leukemia (AML) is characterized by an accumulation of immature myeloid blasts in the bone marrow (BM).1 By providing cell-cell interactions and secreted factors, the BM niche supports AML and normal hematopoietic stem and progenitor cells (HSPC).1,2 A dysregulation of cytokines in the BM microenviron- ment upon AML development contributes to the selective advantage of leukemia stem cells,1 a self-renewing population of leukemia cells that constitutes a chemo- resistant reservoir responsible for disease relapse.3
To identify factors that regulate AML cells, we recently developed an in vitro cytokine screen using fluorescently labeled c-Kit+ leukemia cells mixed with corre- sponding normal BM cells, allowing us to successfully identify both negative and positive regulators of AML cells.4 However, to assess effects on leukemia stem cells, there is a strong demand to improve such screens to evaluate the impact of cytokines on the leukemia-initiating capacity of cells more directly using an in vivo readout. A major challenge for combining ex vivo screens with in vivo read-out of stem cell function is the large number of experimental animals needed to provide meaningful data. Hence, new methods that allow for a multiplexed in vivo read-out
Correspondence:
MARCUS JÄRÅS
marcus.jaras@med.lu.se
Received: February 27, 2018. Accepted: February 21, 2019. Pre-published: February 28, 2019.
doi:10.3324/haematol.2018.192062
Check the online version for the most updated information on this article, online supplements, and information on authorship & disclosures: www.haematologica.org/content/104/10/2006
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2006
haematologica | 2019; 104(10)
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