Loss of Capicua alters early T cell development and predisposes mice to T cell lymphoblastic leukemia/lymphoma

• DOI: 10.1073/pnas.1716452115
• Publication Date: 2018-01-30T17:05:13Z
• Authors: Qiumin Tan; Lorenzo Brunetti; Maxime W. C. Rous...; Hsiang-Chih Lu; Ying-Wooi Wan; Jean-Pierre Revelli; Zhandong Liu; Margaret A. Goodell; Huda Y. Zoghbi
• Keywords: Mice, Knockout; 0303 health sciences; T-Lymphocytes; Cell Differentiation; Precursor T-Cell Lymphoblastic Leukemia-Lymphoma; Capicua; MYC transcriptional program; NOTCH activation; T cell development; T-ALL; Animals; Cells, Cultured; Mice; Mice, Knockout; Mutation; Precursor T-Cell Lymphoblastic Leukemia-Lymphoma; Proto-Oncogene Proteins c-myc; Receptor, Notch1; Repressor Proteins; Signal Transduction; T-Lymphocytes; ras Proteins; Cell Differentiation; Disease Susceptibility; 3. Good health; Proto-Oncogene Proteins c-myc; Repressor Proteins; Mice; 03 medical and health sciences; Mutation; ras Proteins; Animals; Disease Susceptibility; Receptor, Notch1; Cells, Cultured; Signal Transduction

Capicua (CIC) regulates a transcriptional network downstream of the RAS/MAPK signaling cascade. In Drosophila , CIC is important for many developmental processes, including embryonic patterning and specification of wing veins. In humans, CIC has been implicated in neurological diseases, including spinocerebellar ataxia type 1 (SCA1) and a neurodevelopmental syndrome. Additionally, we and others have reported mutations in CIC in several cancers. However, whether CIC is a tumor suppressor remains to be formally tested. In this study, we found that deletion of Cic in adult mice causes T cell acute lymphoblastic leukemia/lymphoma (T-ALL). Using hematopoietic-specific deletion and bone marrow transplantation studies, we show that loss of Cic from hematopoietic cells is sufficient to drive T-ALL. Cic -null tumors show up-regulation of the KRAS pathway as well as activation of the NOTCH1 and MYC transcriptional programs. In sum, we demonstrate that loss of CIC causes T-ALL, establishing it as a tumor suppressor for lymphoid malignancies. Moreover, we show that mouse models lacking CIC in the hematopoietic system are robust models for studying the role of RAS signaling as well as NOTCH1 and MYC transcriptional programs in T-ALL.