Oncogenic deubiquitination controls tyrosine kinase signaling and therapy response in acute lymphoblastic leukemia

Area of Science:

• Molecular Biology
• Oncology
• Biochemistry

Background:

• Kinase signaling pathway dysregulation promotes cancer cell survival and therapy resistance.
• Posttranslational modifications, such as deubiquitination, play a critical role in regulating cellular processes in cancer.

Purpose of the Study:

• To investigate the role of deubiquitination in regulating kinase signaling and nuclear receptor activity in T cell acute lymphoblastic leukemia (T-ALL).
• To identify potential therapeutic targets for T-ALL based on deubiquitination mechanisms.

Main Methods:

• Assessed USP11 expression in T-ALL patient samples and correlated it with prognosis.
• Utilized genetic ablation of USP11 and USP7 in vivo models.
• Investigated the interaction between USP11, USP7, and LCK using co-immunoprecipitation and enzymatic assays.
• Analyzed the impact of LCK activity on glucocorticoid receptor (GR) expression and sensitivity.
• Examined enhancer-promoter interactions to understand transcriptional activation of GR target genes.

Main Results:

• USP11 is highly expressed in T-ALL and associated with poor prognosis.
• USP11 ablation inhibits leukemia progression and preserves normal hematopoiesis.
• USP11 forms a complex with USP7 to deubiquitinate and activate LCK.
• Impaired LCK activity increases GR expression and glucocorticoid sensitivity.
• Genetic knockout of USP7 enhances the efficacy of glucocorticoids in T-ALL treatment.
• Deubiquitinase activity regulates GR target gene transcription via enhancer-promoter interactions.

Conclusions:

• Dysregulated deubiquitination by USP11 and USP7 controls leukemia cell survival and drug resistance in T-ALL.
• Targeting the USP11-USP7-LCK axis and enhancing glucocorticoid receptor signaling presents a promising therapeutic strategy for T-ALL.
• This study uncovers novel therapeutic combinations for targeting leukemia.