Study On Plasma Exosome Proteomics And Diagnostic Markers Of Liver Cancer In Patients With Liver Cancer

Objective: Liver cancer is one of the most common cancers in the world.To date,preliminary screening and laboratory diagnosis of liver cancer have relied on serum Alpha fetal protein(AFP)values.However,there are still30%-40% hepatocellular carcinoma(HCC)patients who are negative for alpha-fetoprotein,which increases the difficulty in diagnose in this part of patients and even leads to the delay of early treatment.At present,there are still few studies on the relationship between exosomes and hepatocellular carcinoma.In this study,the plasma exosomes of hepatocellular carcinoma patients will be analyzed by proteomics to find the valuable diagnostic markers for hepatocellular carcinoma.Methods: First,we extracted plasma exosomes from 21 HCC patients and15 healthy volunteers using an exosome extraction kit.Exosomes from HCC patients or healthy control were randomly divided into three groups and all samples in each group were mixed,the tag free proteomics technology with liquid chromatography-tandem mass spectrometry(LC/MS/MS)method was used for protein quantification in the 6 groups,bioinformatics method including KEGG,GO were used for proteomics data analysis.Another 7 HCC patients and 7 healthy volunteers were recruited and exosomes were extracted following by Western blot(WB)to verify part of the proteomic results.Results: 1.The results of proteomics test indicated that there were differences in the content of 27 kinds proteins in plasma exosomes between HCC patients and normal controls.There were 13 kinds of up-regulation and 14 kinds of down-regulation.2.In the analysis of KEGG pathway,Growth hormone synthesis,secretion and action,Complement and cascades showed significant differences in HCC group comparing to the control.3.In the two comparison groups,GO analysis showed that positive regulation of heterotypic cell-cell adhesion and other important Biological processes(BP);Cellular components(CC)such as growth factor complex;The insulin-like growth factor binding and other Molecular functions(MF)were significantly changed.4.WB verification results: C1QB(Complement C1 Q subcomponent subunit B),C1QC(Complement C1 Q subcomponent subunit C),C4BPB(C4b-binding protein beta chain)and TGFBI(Transforming growth factor-beta-induced)were highly expressed in the plasma exosomes of HCC patients.Conclusion: C1QB,C1QC,C4 BPB and TGFBI are highly expressed in plasma exosomes of hepatocellular carcinoma patients and can be used as potential diagnostic markers for HCC.