[Screening Serum Differential Proteins in Children with Acute Promyelocytic Leukemia Based on iTRAQ Technique]

To screen the serum differentially expressed proteins of APL in children.

Serum protein expression profiles from 20 cases of normal healthy controls, and 20 cases of APL patients were detected by iTRAQ (isobaric tag for relative and absolute quantification)labeling coupled with two-dimensional liquid chromatography-tandem mass spectrometry(2DLC-MS/MS), and analyzed by bioinformatics software. S100A8, LRG1 and SPARC were validated by ELISA. ROC was built by SPSS 20.0 software.

Analysis identified 83 differentially expressed proteins in APL serum compared with control according to our defined criteria, of which 33 proteins were up-regulated and 50 proteins were down-regulated (P<0.05)．IPA analysis revealed that these differentially expressed proteins were related to the function of Cellular Movement, Immune Cell Trafficking, Hematological System Development and Function, Cell-To-Cell Signaling and Interaction, Tissue Development, and involved in a variety of signalling Pathways, the most representative pathways including LXR/RXR Activation and Acute Phase Response Signaling. S100A8 and LRG1 were found to be elevated and SPARC was markedly down-regulated in serum of childhood APL when compared to the normal controls as examined by ELISA (P<0.05), which was consistent with the iTRAQ result. The overall predictive accuracy of each protein was reflected by the area under the ROC curve(AUC), S100A8,LRG1 and SPARC with ROC areas of 0.841,1.000 and 0.944 respectively.

S100A8,LRG1 and SPARC may be serve as serum candidate biomarkers for pediatric APL.