Dysregulated arginine metabolism in precursor B-cell acute lymphoblastic leukemia in children: a metabolomic study

Abstract

Background: Precursor B-cell acute lymphoblastic leukemia (B-ALL) is the most common cancers in children. Failure of induction chemotherapy is a major factor leading to relapse and death in children with B-ALL. Given the importance of altered metabolites in the carcinogenesis of pediatric B-ALL, studying the metabolic profile of children with B-ALL during induction chemotherapy and in different minimal residual disease (MRD) status may contribute to the management of pediatric B-ALL.

Methods: We collected paired peripheral blood plasma samples from children with B-ALL at pre- and post-induction chemotherapy and analyzed the metabolomic profiling of these samples by ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS). Healthy children were included as controls. We selected metabolites that were depleted in pediatric B-ALL and analyzed the concentrations in pediatric B-ALL samples. In vitro, we study the effects of the selected metabolites on the viability of ALL cell lines and the sensitivity to conventional chemotherapeutic agents in ALL cell lines.

Results: Forty-four metabolites were identified with different levels between groups. KEGG pathway enrichment analyses revealed that dysregulated linoleic acid (LA) metabolism and arginine (Arg) biosynthesis were closely associated with pediatric B-ALL. We confirmed that LA and Arg were decreased in pediatric B-ALL samples. The treatment of LA and Arg inhibited the viability of NALM-6 and RS4;11 cells in a dose-dependent manner, respectively. Moreover, Arg increased the sensitivity of B-ALL cells to L-asparaginase and daunorubicin.

Conclusion: Arginine increases the sensitivity of B-ALL cells to the conventional chemotherapeutic drugs L-asparaginase and daunorubicin. This may represent a promising therapeutic approach.

Keywords: Arginine; Linoleic acid; Metabolomic profiling; Minimal residual disease; Precursor B-cell acute lymphoblastic leukemia.

Fig. 1

Metabolic changes were observed in the peripheral plasma of pediatric B-ALL. A, D OPLS-DA score plots for comparison between healthy controls and pediatric B-ALL in cohort A and cohort B at pre-induction, respectively. G OPLS-DA score plots for comparison between cohort A and cohort B in B-ALL at post-induction. B, E, H The cross-validation results, tested with a permutation method repeated 1000 times. Both R2 and Q2 are greater than 0.5. C, F The VIP score plots for showing the impacts of differential metabolites in B-ALL compared to healthy controls. I The VIP score plots for showing the impacts of altered metabolites on MRD status after B-ALL induction chemotherapy

Fig. 2

The identification of pathogenic metabolites in pediatric B-ALL. Hierarchical cluster analysis was performed for metabolite differences in (A) children with B-ALL at pre-induction compared to healthy controls and (B) children with B-ALL of different MRD status at post-induction chemotherapy. The red color represents high relative concentrations of metabolites in each group, while the blue color represents low relative concentrations of metabolites in each group

Fig. 3

KEGG pathway enrichment analysis. Significant changes of the metabolites were observed in (A) children with B-ALL at the time of diagnosis compared to healthy controls, and (B) children with B-ALL of different MRD status after induction chemotherapy

Fig. 4

The mass spectral patterns and the relative abundance of linoleic acid and arginine. A-B Fragmentation profiles of LA and Arg on MS, respectively. C Comparison of the relative abundance of linoleic acid between Cohort A and Cohort B at pre-induction and healthy controls. D Comparison of the relative abundance of Arg in cohort A and cohort B at post-induction in B-ALL

Fig. 5

LA and Arg inhibited the viability of ALL cell lines. A-C Arg and (D-F) LA inhibited the viability of NALM-6, RS4;11 cell lines rather than normal PBMC, as determined by CCK8 assay. Data are expressed as mean ± SEM of three independent experiments. *p < .05, **p < .01, ***p < .001, ****p < .0001

Fig. 6

Effects of Arg treatment alone and in combination with different chemotherapic drugs in (A-D) RS4;11 and in (E-H) NALM-6 cells. Cells were treated with indicated concentrations and fixed molar ratios and viability assessed by CCK8 assay after 24 h incubation. Data are expressed as mean ± SEM of three independent experiments. *p < .05, **p < .01, ***p < .001