Disparities in AML treatment

About This Grant

The outcomes for acute myeloid leukemia (AML) have remained abysmally poor for the past 30 years. It has been shown that AML patients with wild-type FMS-like receptor tyrosine kinase (FLT3) and mutant nucleophosmin (NPM1mut) show improved overall survival and relapse-free survival. Transcription factor FOXM1 interacts with NPM in human cancer cells, including AML cells, and mutant NPM drives FOXM1 to the cytoplasm, where FOXM1 become inactivated. Our data indicate that favorable outcome for White AML patients with NPM1mut based on FOXM1 inactivation. However, this is not true for Black AML patients and recently it has been shown that black AML patients with mutant NPM1 do not have favorable outcome of treatment. For example, Black patients with NPM1 mutations who were FLT3-wt had worse DFS (3-year rates: 13% versus 55%, P = 0.002), EFS (3-year rates: 10% versus 46%, P = 0.01) and OS (10% versus 61%, P < 0.001) than White patients. First, we will determine if NPM1 mutant status determines FOXM1 cytoplasmic localization/inactivation in primary samples from Black AML patients. We will use de-identified AML bone marrow biopsy samples at the time of diagnosis that will be provided by Dr. Khan (NU). We will study correlations between NPM1 mutations, NPM/FOXM1 localization, BCL2A1 expression and prognosis in 80 primary AML patient bone marrow biopsies as follow: White patient samples: FLT3wt/NPM1wt (20 samples) and FLT3wt/NPM1mut (20 samples); Black patient samples: FLT3wt/NPM1wt (20 samples) and FLT3wt/NPM1mut (20 samples). Bone marrow biopsy specimens at the time of diagnosis of AML will be identified, sectioned and fixed on slides. Next, we will perform multiplex immunofluorescence imaging to examine simultaneous NPM and FOXM1 nuclear/cytoplasmic localization and BCL2A1 expression by quantifying its expression in the leukemia cells of interest. These experiments will show whether FOXM1 is localized in cytoplasm of Black AML patients with mutant NPM1. Next, we will test whether FOXM1- independent expression of BCL2A1 determines unfavorable outcome in Black AML patients with mutant NPM1. Additionally, we will identify differentially expressed gene(s) in primary AML samples from Black/White patients with mutant NPM1 that are potentially responsible for unfavorable outcome for Black patients. We will perform RNA-seq in 40 AML primary samples (20-White AML patients with mutant NPM1; 20- Black AML patients with mutant NPM1). We will isolate the RNA from AML primary samples and single-read sequencing for 40 bases will be done on an Illumina HiSeq Analyzer. We will identify the differentially expressed (DE) genes (log2 expression fold change >2 or <2, false discovery rate <0.05). The expression changes will be confirmed by qRT-qPCR. These experiments will reveal whether there are differences in gene expression in White versus Black AML patient samples with mutant NPM1 that could explain difference in Black/White NPM1 mutant AML patient outcomes.