A distinct glucose metabolism signature of acute myeloid leukemia with prognostic value

Abstract

Acute myeloid leukemia (AML) is a group of hematological malignancies with high heterogeneity. There is an increasing need to improve the risk stratification of AML patients, including those with normal cytogenetics, using molecular biomarkers. Here, we report a metabolomics study that identified a distinct glucose metabolism signature with 400 AML patients and 446 healthy controls. The glucose metabolism signature comprises a panel of 6 serum metabolite markers, which demonstrated prognostic value in cytogenetically normal AML patients. We generated a prognosis risk score (PRS) with 6 metabolite markers for each patient using principal component analysis. A low PRS was able to predict patients with poor survival independently of well-established markers. We further compared the gene expression patterns of AML blast cells between low and high PRS groups, which correlated well to the metabolic pathways involving the 6 metabolite markers, with enhanced glycolysis and tricarboxylic [corrected] acid cycle at gene expression level in low PRS group. In vitro results demonstrated enhanced glycolysis contributed to decreased sensitivity to antileukemic agent arabinofuranosyl cytidine (Ara-C), whereas inhibition of glycolysis suppressed AML cell proliferation and potentiated cytotoxicity of Ara-C. Our study provides strong evidence for the use of serum metabolites and metabolic pathways as novel prognostic markers and potential therapeutic targets for AML.

Figure 1

Metabolic alteration of AML. OPLS-DA score plots showed a global metabolic difference between AML and HC in the training set (A) and validation set (B). (C) Metabolomic profiles of 9 AML subtypes based on WHO classification. (D) Metabolomic profiles of different cytogenetic risk groups of AML patients. (E) Heat map showed 6 differentially expressed serum metabolites involved in glucose metabolism in AML compared with HC. gr1, AML with t(15;17); gr2, AML with t(8;21); gr3, AML with t(16;16); gr4, AML with minimal differentiation; gr5, AML without maturation; gr6, AML with maturation; gr7, acute myelomonocytic leukemia; gr8, acute monoblastic/monocytic leukemia; g9, acute erythroid leukemia.

Figure 2

Prognostic analysis of CN-AML with low and high PRSs. Survival curves showed OS and EFS of CN-AML with low and high PRSs in the training set (A-B) and the validation set (C-D). P values were calculated by means of log-rank test.

Figure 3

Glucose metabolism and mRNA expression of related metabolic genes in CN-AML patients with low and high PRSs. (A) Heat map showed 6 serum metabolite biomarkers between low and high PRS groups. (B) Heat map showed changes in the expression of genes involved in glucose metabolism of low and high PRS groups. Shades of red and green represented high or low expression (see color scale). Each column represented a patient with low PRS (denoted by deep pink bar) or a patient with high PRS (denoted by deep sky blue bar).

Figure 4

The mRNA expression of genes involved in glucose metabolism and the biological role of aberrant glycolysis in AML cells. (A) Assay of the expression of genes involved in glucose metabolism in 5 AML cell lines, HL-60, U937, OCI-AML3, THP-1, and KG-1. Target gene expression in U937, OCI-AML3, THP-1, and KG-1 was normalized to those in HL-60 (which were set at 1) and presented as fold changes relative to HL-60. **P < .01 vs HL-60. (B-C) Cell viability curves of AML cell lines treated with glycolytic inhibitors 2-DG and DCA, respectively. (D) Western blot showed downregulation of HK1 in U937 and OCI-AML3 by shRNA. (E) Increased sensitivity to Ara-C in U937 and OCI-AML3 with reduced HK1 expression. *P < .05 vs shNT. (F-I) Synergistic effect of 2-DG and Ara-C on U937, OCI-AML3, HL-60, and KG-1, respectively. (J-K) Cell viability curves of AML primary blast cells treated with glycolytic inhibitors 2-DG and DCA, respectively. (L-N) Synergistic effect of 2-DG and Ara-C on AML primary blast cells of patient 1, patient 2, and patient 3, respectively. Each measure was performed with at least 3 duplicates and was expressed as mean ± SE.