Proteomic Profiles and Biological Processes of Relapsed vs. Non-Relapsed Pediatric Hodgkin Lymphoma.

Ombretta Repetto,Maurizio Mascarin,Maurizio Bianchi,Alessandra Sala,Massimo Tedeschi,Salvatore Buffardi,Lara Mussolin,Caterina Elia,Valli De Re,Roberta Burnelli

doi:10.3390/ijms21062185

Abstract

The identification of circulating proteins associated with relapse in pediatric Hodgkin lymphoma (HL) may help develop predictive biomarkers. We previously identified a set of predictive biomarkers by difference gel electrophoresis. Here we used label-free quantitative liquid chromatography-mass spectrometry (LC-MS/MS) on plasma collected at diagnosis from 12 children (age 12–16 years) with nodular sclerosis HL, including six in whom the disease relapsed within 5 years of treatment in the LH2004 trial. Plasma proteins were pooled in groups of three, separately for non-relapsing and relapsing HL, and differentially abundant proteins between the two disease states were identified by LC-MS/MS in an explorative and validation design. Proteins with a fold change in abundance >1.2 or ≤0.8 were considered “differentially abundant”. LC-MS/MS identified 60 and 32 proteins that were more abundant in non-relapsing and relapsing HL plasma, respectively, in the explorative phase; these numbers were 39 and 34 in the validation phase. In both analyses, 11 proteins were more abundant in non-relapsing HL (e.g., angiotensinogen, serum paraoxonase/arylesterase 1, transthyretin), including two previously identified by difference gel electrophoresis (antithrombin III and α-1-antitrypsin); seven proteins were more abundant in relapsing HL (e.g., fibronectin and thrombospondin-1), including two previously identified proteins (fibrinogen β and γ chains). The differentially abundant proteins participated in numerous biological processes, which were manually grouped into 10 biological classes and 11 biological regulatory subclasses. The biological class Lipid metabolism, and its regulatory subclass, included angiotensinogen and serum paraoxonase/arylesterase 1 (more abundant in non-relapsing HL). The biological classes Immune system and Cell and extracellular matrix architecture included fibronectin and thrombospondin-1 (more abundant in relapsing HL). These findings deepen our understanding of the molecular scenario underlying responses to therapy and provide new evidence about these proteins as possible biomarkers of relapse in pediatric HL.

Highlights

Pediatric Hodgkin lymphoma (HL) represents 6% of all childhood cancers and has a 5-year survival rate of approximately 90–95% [1]
Label-free quantitative LC-mass spectrometry (MS)/MS was performed on plasma proteins from six children with relapsing HL and six with non-relapsing HL (Table 1)
We found that some proteins in the biological class Cell and extracellular matrix (ECM) organization were more abundant in non-relapsing than relapsing HL

Summary

Introduction

Pediatric Hodgkin lymphoma (HL) represents 6% of all childhood cancers and has a 5-year survival rate of approximately 90–95% [1]. Several studies use a candidate-protein approach with described putative biomarkers measurable by enzyme-linked immunosorbent assay in pretreatment blood or serum and are predictive of treatment outcome (reviewed in [4]). These proteins include CD54 [5], heparanase [6], and VEGF [7]. Qi et al 2008 [8] used mass spectrometry (MS)-based proteomic profiling with surface enhanced laser desorption/ionization to identify serum proteins discriminating advanced HL stages, and α-1-antitrypsin emerged as a candidate biomarker for high grade (III/IV) pediatric HL. When applied to the highly variable plasma matrix, DIGE has difficulty separating extremely acidic, basic, or hydrophobic proteins, and rare or comigrating proteins may not be detected [12]

Methods

Discussion

Conclusion