Understanding the Role of p53 in Metabolic Regulation in Acute Myeloid Leukemia (AML)

Abstract

This study focused on investigating the role of mutations in the TP53 tumor suppressor gene in the metabolic regulation of human acute myeloid leukemia (AML) using the Tohoku Hospital Pediatrics-1 (THP-1) cell line as a model. The THP-1 cell line represents the AML-M5 subtype, which is a subtype that mainly affects young children (< 2 years). We generated stable isogenic cell lines by overexpressing TP53 in the THP-1 cell line via different constructs of plenti6-based plasmids. The generated cell lines were TP53 WT THP-1, TP53R175H THP-1, and TP53R273H THP-1. The TP53R175H and TP53R273H missense mutations are among the most common mutations of TP53 in human cancer. In AML, their overexpression on a background of TP53 loss has been linked to gain of function phenotypes in cell-based research, suggesting tumor cell growth, invasion, migration, treatment resistance, and metastasis. Specifically, the mutation R175H leads to structural changes in the binding domain of the TP53 gene, while the mutation R273H changes the protein’s ability to bind DNA in the TP53 gene. Subsequently, we identified signature genes associated with TP53 WT found in TP53 WT THP-1 cell line (n=4), TP53R175H found in TP53R175H THP-1 cell line 1 (n=34), and TP53R273H found in TP53R273H THP-1 cell line (n=111) with the most significant changes in metabolic processes, GO:0008152. Moreover, we found that TP53R175H and TP53R273H decreased oxidative phosphorylation and TP53R175H increased the Warburg effect in the mitochondria in the AML cells. Furthermore, we found by using the TARGET AML cohort that AML patients with AML-TP53R175H had a significantly poor prognosis associated with a relatively long (> 5-years) survival compared to the patients with other signature genes (n=440, p=0.006432). In contrast, we found by using the TCGA LAML cohort that AML patients with AML-TP53R273H had a significantly poor prognosis associated with a relatively short (< 5-years) survival compared to the patients with other signature genes (n=179, p=0.01629). This study supports further evaluation of understanding the role of p53 mutants in metabolic regulation in AML, which might provide a framework for predicting AML patient survival and suggest potential p53-based therapy and novel strategies to treat human AML.