[Clinical Significance of USP5 Expression Level in Acute Myeloid Leukemia and Its Regulatory Effects on AKT/mTOR/4EBP1 Signaling Pathway].

Objective: To investigate the clinical significance, functional role and potential downstream mechanism of USP5 in acute myeloid leukemia (AML).

Methods: The expression of USP5 in AML and normal tissues and its correlation with patients' survival were analyzed based on TCGA database. USP5 was knocked down and overexpressed in Jurkat and HL-60 cells using lentivirus. USP5 mRNA and protein expression were detected by RT-qPCR and Western blot, respectively. Cell proliferation and growth were measured by CCK-8 and methylcellulose colony-forming assay. Flow cytometry was used to analyze cell cycle and apoptosis.

Results: USP5 was highly expression in AML compared with normal tissues. Up-regulation of USP5 was negatively correlated with the survival of AML patients. USP5 knockdown and overexpression inhibited and promoted the proliferation and colony growth of AML cells, respectively. Cell cycle arrest and apoptosis were induced in USP5 knockdown Jurkat and HL-60 cells. Furthermore, USP5 knockdown inhibited the phosphrylation of AKT, mTOR and 4EBP1.

Conclusion: Overexpression of USP5 predicts poor survival of AML patients. Targeting USP5 suppresses AKT/mTOR/4EBP1 signaling and reduces the proliferation and growth of AML cells.