Translatome changes in acute myeloid leukemia cells post exposure to pegcrisantaspase and venetoclax

The clinical outcomes of patients with acute myeloid leukemia (AML) treated with available therapy remain unsatisfactory. We recently reported that the BCL-2 inhibitor venetoclax synergizes with pegcrisantaspase (Ven-PegC) and exhibits remarkable in vivo efficacy in a preclinical model of AML with complex karyotype. The Ven-PegC combination blocks synthesis of proteins in AML cells by inhibiting cap-dependent translation of mRNA. To further explore the impact of Ven-PegC on protein translation, we used polysome profiling and high-throughput RNA sequencing to characterize Ven-PegC-dependent changes to the translatome. Here we report that the translation of five mRNAs, including two microRNAs, one rRNA, and two mitochondrial genes, was altered after exposure to all three treatments (Ven, PegC, and Ven-PegC). We focused our translatome validation studies on six additional genes related to translational efficiency that were modified by Ven-PegC. Notably, Ven-PegC treatment increased the RNA translation and protein levels of Tribbles homologue 3 (TRIB3), eukaryotic translation initiation factor 3 subunit C (eIF3C), doublesex and mab-3-related transcription factor 1 (DMRT1), and salt-inducible kinase 1 (SIK1). We validated the observed changes in gene/protein expression in vitro and confirmed our cell line-based studies in the bone marrow of an AML patient-derived xenograft model after Ven-PegC treatment. These results support examining alterations in the translatome post chemotherapy to offer insight into the drug's mechanism of action and to inform future therapeutic decisions.