Targeting lactate dehydrogenase A (LDHA) exerts antileukemic effects on T-cell acute lymphoblastic leukemia

Abstract

Background: T-cell acute lymphoblastic leukemia (T-ALL) is an uncommon and aggressive subtype of acute lymphoblastic leukemia (ALL). In the serum of T-ALL patients, the activity of lactate dehydrogenase A (LDHA) is increased. We proposed that targeting LDHA may be a potential strategy to improve T-ALL outcomes. The current study was conducted to investigate the antileukemic effect of LDHA gene-targeting treatment on T-ALL and the underlying molecular mechanism.

Methods: Primary T-ALL cell lines Jurkat and DU528 were treated with the LDH inhibitor oxamate. MTT, colony formation, apoptosis, and cell cycle assays were performed to investigate the effects of oxamate on T-ALL cells. Quantitative real-time PCR (qPCR) and Western blotting analyses were applied to determine the related signaling pathways. A mitochondrial reactive oxygen species (ROS) assay was performed to evaluate ROS production after T-ALL cells were treated with oxamate. A T-ALL transgenic zebrafish model with LDHA gene knockdown was established using CRISPR/Cas9 gene-editing technology, and then TUNEL, Western blotting, and T-ALL tumor progression analyses were conducted to investigate the effects of LDHA gene knockdown on T-ALL transgenic zebrafish.

Results: Oxamate significantly inhibited proliferation and induced apoptosis of Jurkat and DU528 cells. It also arrested Jurkat and DU528 cells in G0/G1 phase and stimulated ROS production (all P < 0.001). Blocking LDHA significantly decreased the gene and protein expression of c-Myc, as well as the levels of phosphorylated serine/threonine kinase (AKT) and glycogen synthase kinase 3 beta (GSK-3β) in the phosphatidylinositol 3'-kinase (PI3K) signaling pathway. LDHA gene knockdown delayed disease progression and down-regulated c-Myc mRNA and protein expression in T-ALL transgenic zebrafish.

Conclusion: Targeting LDHA exerted an antileukemic effect on T-ALL, representing a potential strategy for T-ALL treatment.

Keywords: CRISPR/Cas9 gene-editing; LDHA; T-cell lymphoblastic leukemia; oxamate; transgenic zebrafish model.