Genetic studies in T-cell acute lymphoblastic leukemia have uncovered a remarkable complexity of oncogenic and loss-of-function mutations. Amongst this plethora of genetic changes, NOTCH1 activating mutations stand out as the most frequently occurring genetic defect, identified in more than 50% of T-cell acute lymphoblastic leukemias, supporting a role as an essential driver for this gene in T-cell acute lymphoblastic leukemia oncogenesis. In this study, we aimed to establish a comprehensive compendium of the long non-coding RNA transcriptome under control of Notch signaling. For this purpose, we measured the transcriptional response of all protein coding genes and long non-coding RNAs upon pharmacological Notch inhibition in the human T-cell acute lymphoblastic leukemia cell line CUTLL1 using RNA-sequencing. Similar Notch dependent profiles were established for normal human CD34(+) thymic T-cell progenitors exposed to Notch signaling activity in vivo. In addition, we generated long non-coding RNA expression profiles (array data) from ex vivo isolated Notch active CD34(+) and Notch inactive CD4(+)CD8(+) thymocytes and from a primary cohort of 15 T-cell acute lymphoblastic leukemia patients with known NOTCH1 mutation status. Integration of these expression datasets with publicly available Notch1 ChIP-sequencing data resulted in the identification of long non-coding RNAs directly regulated by Notch activity in normal and malignant T cells. Given the central role of Notch in T-cell acute lymphoblastic leukemia oncogenesis, these data pave the way for the development of novel therapeutic strategies that target hyperactive Notch signaling in human T-cell acute lymphoblastic leukemia.
Durinck, Kaat; Wallaert, Annelynn; Van de Walle, Inge; Van Loocke, Wouter; Volders, Pieter-Jan; Vanhauwaert, Suzanne; Geerdens, Ellen; Benoit, Yves; Van Roy, Nadine; Poppe, Bruce; Soulier, Jean; Cools, Jan; Mestdagh, Pieter; Vandesompele, Jo; Rondou, Pieter; Van Vlierberghe, Pieter; Taghon, Tom; Speleman, Frank. HAEMATOLOGICA, 99 (12):1808-1816; 10.3324/haematol.2014.115683 DEC 2014