Comparative Analysis of Systemic and Tumor Microenvironment Proteomes From Children With B-Cell Acute Lymphocytic Leukemia at Diagnosis and After Induction Treatment

Proteomics in Childhood Acute Lymphoblastic Leukemia: Challenges and Opportunities

Acute lymphoblastic leukemia (ALL) is the most common cancer in children and one of the success stories in cancer therapeutics. Risk-directed therapy based on clinical, biologic and genetic features has played a significant role in this accomplishment. Despite the observed improvement in survival rates, leukemia remains one of the leading causes of cancer-related deaths. Implementation of next-generation genomic and transcriptomic sequencing tools has illustrated the genomic landscape of ALL. However, the underlying dynamic changes at protein level still remain a challenge. Proteomics is a cutting-edge technology aimed at deciphering the mechanisms, pathways, and the degree to which the proteome impacts leukemia subtypes. Advances in mass spectrometry enable high-throughput collection of global proteomic profiles, representing an opportunity to unveil new biological markers and druggable targets. The purpose of this narrative review article is to provide a comprehensive overview of studies that have utilized applications of proteomics in an attempt to gain insight into the pathogenesis and identification of biomarkers in childhood ALL.

Quantitative Plasma Proteomics to Identify Candidate Biomarkers of Relapse in Pediatric/Adolescent Hodgkin Lymphoma

Classical pediatric Hodgkin Lymphoma (HL) is a rare malignancy. Therapeutic regimens for its management may be optimized by establishing treatment response early on. The aim of this study was to identify plasma protein biomarkers enabling the prediction of relapse in pediatric/adolescent HL patients treated under the pediatric EuroNet-PHL-C2 trial. We used untargeted liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based proteomics at the time of diagnosis—before any therapy—as semiquantitative method to profile plasma proteins specifically associated with relapse in 42 children with nodular sclerosing HL. In both the exploratory and the validation cohorts, six proteins (apolipoprotein E, C4b-binding protein α chain, clusterin, fibrinogen γ chain, prothrombin, and vitronectin) were more abundant in the plasma of patients whose HL relapsed (|fold change| ≥ 1.2, p < 0.05, Student’s t-test). Predicting protein function with the Gene Ontology classification model, the proteins were included in four biological processes (p < 0.01). Using immunoblotting and Luminex assays, we validated two of these candidate biomarkers—C4b-binding protein α chain and clusterin—linked to innate immune response function (GO:0045087). This study identified C4b-binding protein α chain and clusterin as candidate early plasma biomarkers of HL relapse, and important for the purpose of shedding light on the molecular scenario associated with immune response in patients treated under the EuroNet-PHL-C2 trial.

Impact of the induction phase chemotherapy on cytokines and oxidative markers in peripheral and bone marrow plasma of children with acute lymphocytic leukemia

B-cell acute lymphocytic leukemia (B-ALL) is the main neoplasia affecting children worldwide, in which cytotoxic chemotherapy remains the main treatment modality. In this study, we analyzed the profile of inflammatory markers concerning oxidative stress and cytokines in 17 B-ALL patients. Peripheral blood (PB) and bone marrow (BM) samples were collected and evaluated for the pro-oxidative status (nitric oxide products-NOx and hydroperoxides), antioxidants (sulfhydryl groups-SH and total radical-trapping antioxidant parameter-TRAP), and cytokines (TNF-α, IFN-γ), at diagnosis (D0) to and the end of the induction phase (D28). At D28, hydroperoxides were higher in PB, concomitant to TNF-α levels. INF-γ was increased in the BM at D28. Hydroperoxides were higher in patients presenting malignant cells in BM and/or PB after treatment, a condition named minimal residual disease (MRD) when compared to those without MRD at D28. These findings suggest that oxidative stress and cytokines vary across the B-ALL induction phase, and lipid peroxidation is a potential marker associated with MRD status.

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B-ALL is the main neoplasia in childhood.

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Chemotherapy is the main modality for B-ALL treatment, and the success in the initial phase is determinant on the rates of cure.

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Oxidative stress is one of the main known mechanisms of action of chemotherapy.

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We showed that the initial chemotherapy of B-ALL is mediated by oxidative stress fluctuations

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Lipid peroxides are associated to disease elimination in the induction phase.