Identification Of Differentially Expressed Proteins In The Peripheral Blood Mononuclear Cell(PBMC) Of Colorectal Cancer(CRC) By Data Independent Acquision Mass Spectrometry((DIA-MS)) Quantitation Method

Mortality of Colorectal cancer in men and women were 5.5% and 7.7 respectively in 2014,according to the world health organization.Colorectal cancer is a common digestive system cancer and its development is a complex and multistep process,so cancer occurrence and progress affect human immune system.There are lots of researches demonstrating that the immune system's reaction during the occurrence or development of the malignancy.Peripheral blood mononuclear cell(PBMC)is an ideal sample to study the immune functions,which is main part of the immune system and easily available.Here,we quantified 6 colorectal cancer(CRC)and 5 benign intestinal disease patients' PBMC proteins to identify the different expressed proteins in these two types.On one hand,the same amount of protiens from each sample were pooled and the mixture was separated by two dimensional orthogonal High Performance Liquid Chromatography(HPLC)before MS analysis.On the other hand,each sample was separated by one dimensional HPLC separation and MS analysis.Then these two datas were used to build spectral library separately.The second way preforms better than the first one in peptide number and peptide extraction ratio obviously.What's more,it's easy and time-saving.So,11 sample DDA datas were used to build library.Then we utilized a novel MS technology-Data Independent Acquision(DIA),which has high specificity and coverage in our study to quantify and compare the proteomics of these two intestinal dieseases.Based on the quantified results,113 differentially expressed proteins(p < 0.05)were identified,which include 23 up-regulated proteins and 90 down-regulated proteins.GO analysis results showed that down-regulated proteins were significantly enriched in platelet degranulation,regulated exocytosis,exocytosis,vesicle-mediated transport and secretion by cell and secretion biological processes(BP);For molecular function(MF)analysis,the downregulated proteins were enriched in cell adhesion molecule binding,cadherin binding involved in cell-cell adhesion,protein binding involved in cell-cell adhesion,protein binding involved in cell adhesion,cadherin binding.And GO cell component(CC)analysis showed that the downregulated proteins were significantly enriched in the membrane-bounded vesicle,extracellular exosome,extracellular vesicle,extracellular organelle,extracellular region part,extracellular region,while up-regulated proteins were not enriched in any cell component.The Reactome pathway analysis shows the down-regulated proteins were enriched in Platelet degranulation,MAP2 K and MAPK activation,P130 Cas linkage to MAPK signaling for integrins,GRB2: SOS provides linkage to MAPK signaling for Integrins,Integrin alphaIIb beta3 signaling,Common Pathway of Fibrin Clot Formation,Integrin cell surface interactions,RHO GTPases activate PAKs,RHO GTPases activate PKNs pathway.The up-regulated proteins were enriched in SRP-dependent cotranslational protein targeting to membrane pathways.Especially,the up-regulated protein Galectin-1 and the downregulated ones Dok-2,AHNAK1 are expected to be biomarkers of CRC in PBMC,which are closely related to immune function.