Bioinformatics analysis of exosome proteome derived from hepatic carcinoma HepG2 cells

Objective:The aim of this study was to analyze the exosome proteome derived from hepatic carcinoma HepG2 cells and normal hepatocytes HL-7702,and look for the key factors in carcinogenesis of hepatocellular carcinoma(HCC).Methods:HepG2 and HL-7702 cells were cultured,and exosome samples were obtained from the culture supernatant and verified.LTQ-Orbitrap Elite mass spectrometry was applied to analyze and identify the exosome proteome derived from the hepatic carcinoma cells and normal liver cells,which was for seeking hepatic carcinoma cells specifically expressed proteins.Furthermore,gene ontology(GO),protein-protein interaction(PPI)network,and pathway enrichment were constructed to analyze hepatic carcinoma cells specifically expressed proteins.Results:The exosomes of HL-7702 expressed 3,366proteins,and the exosomes of HepG2 expressed 2,874proteins,of which 1,224were expressed specifically in HepG2 exosomes.102 target proteins were selected and going on bioinformatics analysis under the condition that the unique peptide was≥1and PSMs≥10.GO analysis results showed that the target expression protein of HepG2 was concentrated on metabolism,proliferation,and localization adhesion function.76target proteins were chosen and formed a PPI network;combining with pathway analysis,ACTN1,FN1,RAC1and GSN were found to be involved in important signaling pathways of HCC.The 26target proteins which not in PPI network were analyzed pathway involved in,respectively.AKR1C2 and C5 were found to be involved in differently important signaling pathways of HCC.Conclusion:Exosomes proteomics provides the sources of specific protein derived from hepatic carcinoma cell;when it combines with bioinformatics analysis,they are able to reveal the important molecules that are related to carcinogenesis of HCC and provide new ideas for investigation of HCC biomarkers.

Patent Propensity in Small Technologybased Firms:Evidence from Zhongguancun Science Park

Using a survey administered in Zhongguancun Science Park in Beijing, China, this paper investigates the impact of R ＆D personnel-related intellectual property management practices on the patent propensity of small technology-based firms. It is found that R＆D personnel- related management practices, including training and reward mechanisms, are effective in enhancing a firm ＇s willingness to patent. In particular, we find that reward mechanisms can negatively moderate the effect of size on a firm ＇s willingness to patent. One implication that emerged from the analysis is that a small firm can counteract its size disadvantage in patenting by introducing a well-developed reward mechanism.