T-ALL can evolve to oncogene independence.

The majority of cases of T-cell acute lymphoblastic leukemia (T-ALL) contain chromosomal abnormalities that drive overexpression of oncogenic transcription factors. However, whether these initiating oncogenes are required for leukemia maintenance is poorly understood. To address this, we developed a tetracycline-regulated mouse model of T-ALL driven by the oncogenic transcription factor Lmo2. This revealed that whilst thymus-resident pre-Leukemic Stem Cells (pre-LSCs) required continuous Lmo2 expression, the majority of leukemias relapsed despite Lmo2 withdrawal. Relapse was associated with a mature phenotype and frequent mutation or loss of tumor suppressor genes including Ikzf1 (Ikaros), with targeted deletion Ikzf1 being sufficient to transform Lmo2-dependent leukemias to Lmo2-independence. Moreover, we found that the related transcription factor TAL1 was dispensable in several human T-ALL cell lines that contain SIL-TAL1 chromosomal deletions driving its overexpression, indicating that evolution to oncogene independence can also occur in human T-ALL. Together these results indicate an evolution of oncogene addiction in murine and human T-ALL and show that loss of Ikaros is a mechanism that can promote self-renewal of T-ALL lymphoblasts in the absence of an initiating oncogenic transcription factor. © 2021. The Author(s), under exclusive licence to Springer Nature Limited.

Citation

Hesham Abdulla, Anh Vo, Benjamin J Shields, Tenae J Davies, Jacob T Jackson, Raed Alserihi, Elizabeth M Viney, Tin Wong, Feng Yan, Nicholas C Wong, Lisa Demoen, David J Curtis, Warren S Alexander, Pieter Van Vlierberghe, Ross A Dickins, Matthew P McCormack. T-ALL can evolve to oncogene independence. Leukemia. 2021 Aug;35(8):2205-2219

Mesh Tags

Substances

PMID: 33483615

search → result