Hyperactive STAT5 hijacks T cell receptor signaling and drives immature T cell acute lymphoblastic leukemia

• Published in: The Journal of clinical investigation 2024-04, Vol.134 (8), p.1-16
• Main Authors: Suske, Tobias, Sorger, Helena, Manhart, Gabriele, Ruge, Frank, Prutsch, Nicole, Zimmerman, Mark W, Eder, Thomas, Abdallah, Diaaeldin I, Maurer, Barbara, Wagner, Christina, Schönefeldt, Susann, Spirk, Katrin, Pichler, Alexander, Pemovska, Tea, Schweicker, Carmen, Pölöske, Daniel, Hubanic, Emina, Jungherz, Dennis, Müller, Tony Andreas, Aung, Myint Myat Khine, Orlova, Anna, Pham, Ha Thi Thanh, Zimmel, Kerstin, Krausgruber, Thomas, Bock, Christoph, Müller, Mathias, Dahlhoff, Maik, Boersma, Auke, Rülicke, Thomas, Fleck, Roman, de Araujo, Elvin Dominic, Gunning, Patrick Thomas, Aittokallio, Tero, Mustjoki, Satu, Sanda, Takaomi, Hartmann, Sylvia, Grebien, Florian, Hoermann, Gregor, Haferlach, Torsten, Staber, Philipp Bernhard, Neubauer, Heidi Anne, Look, Alfred Thomas, Herling, Marco, Moriggl, Richard
• Format: Article
• Language: English
• Subjects: Acute lymphoblastic leukemia; Acute lymphocytic leukemia; Animals; Antigen receptors, T cell; Cancer therapies; Cell activation; Cell cycle; Chemotherapy; Cloning; Comparative analysis; Development and progression; Disease; Genes; Genetic aspects; Health aspects; Humans; Interleukin 7 receptors; Kinases; Leukemia; Lymphocytes; Lymphocytes T; Lymphoma; Medical prognosis; Mice; Mice, Transgenic; Mutation; Pediatrics; Phenotypes; Physiological aspects; Precursor T-Cell Lymphoblastic Leukemia-Lymphoma - genetics; Progenitor cells; Protein-Tyrosine Kinases; Receptors; Receptors, Antigen, T-Cell - genetics; Risk factors; Signal Transduction; Stat3 protein; STAT5; Stat5 protein; STAT5 Transcription Factor - genetics; T cell receptors; T cells; Thymus gland; Transcription factors; Transgenic animals; Transgenic mice; Tyrosine; ZAP-70 protein
• ISSN: 1558-8238; 0021-9738; 1558-8238
• DOI: 10.1172/JCI168536

T cell acute lymphoblastic leukemia (T-ALL) is an aggressive immature T cell cancer. Mutations in IL7R have been analyzed genetically, but downstream effector functions such as STAT5A and STAT5B hyperactivation are poorly understood. Here, we studied the most frequent and clinically challenging STAT5BN642H driver in T cell development and immature T cell cancer onset and compared it with STAT5A hyperactive variants in transgenic mice. Enhanced STAT5 activity caused disrupted T cell development and promoted an early T cell progenitor-ALL phenotype, with upregulation of genes involved in T cell receptor (TCR) signaling, even in absence of surface TCR. Importantly, TCR pathway genes were overexpressed in human T-ALL and mature T cell cancers and activation of TCR pathway kinases was STAT5 dependent. We confirmed STAT5 binding to these genes using ChIP-Seq analysis in human T-ALL cells, which were sensitive to pharmacologic inhibition by dual STAT3/5 degraders or ZAP70 tyrosine kinase blockers in vitro and in vivo. We provide genetic and biochemical proof that STAT5A and STAT5B hyperactivation can initiate T-ALL through TCR pathway hijacking and suggest similar mechanisms for other T cell cancers. Thus, STAT5 or TCR component blockade are targeted therapy options, particularly in patients with chemoresistant clones carrying STAT5BN642H.