To Screen For The Pivotal Proteins In The Process Of Hepatic Fibrosis-Carcinoma By Itraq Technology

AIM:To find the key proteins in the process of hepatic carcinoma.By analysising the differentially expressed protein in hepatic tissue of the hepatic fibrosis-carcinoma animal model at four points in time.METHODS:By establishing hepatic diethylinitrosamine-induced fibrosis-carcinoma model in rat,we can observe pathological features during the process of hepatic carcinoma. To consider the normal feeding rat as the control group. The animals were sacrificed at the end of 4th,10th,12th,18th week respectively. Liver tissue proteins were quantified and identified by iTRAQ (isobaric tags for relative an absolute quantitation) technology with 2DLC-MS/MS (two dimensional liquid chromatography-tandem mass spectrometry). As a reference to the control group, the proteins were analyzed in the four experimental groups. The differentially expressed proteins were further analyzed, by biological process, cell comments, molecular function, signal pathway enrichment and protein interactions.RESULTS:2438 effective proteins were identified in the first test, and 2416 effective proteins were recognized in the second test. We got 2085 effcetive proteins by analyzing comprehensively in total. In the 4th week group, 148 differentially expressed proteins was identified, of which 61 were up-regulated,87 were down-regulated. In the 10th week group,233 differentially expressed proteins was identified, of which 87 were up-regulated, 146 were down-regulated. In the 12th week group,72 differentially expressed proteins was identified, of which 38 were up-regulated,34 were down-regulated. In the 18th week group,573 differentially expressed proteins were identified, of which 210 were up-regulated,363 were down-regulated.23 proteins have changed simultaneously in point in time, of which 10 were up-regulated,13 were down-regulated. The functional annotation of cell biological processes of these differentially expressed proteinsmainly involved in metabolism, cell process, biological regulation and cell signaling. The functional annotation of cell location notes of these differentially expressed proteins mainly involved in organelles, membrane, extracellular matrix, synapses and cytomixis. The functional annotation of molecular function of these differentially expressed proteins mainly participate in catalytic activity, bonding, transfer, enzyme activity regulating and antioxidant. Through the enrichment of signaling pathways, we found that the difference proteins are mainly involved in amino acid degradation, chemical carcinogenesis, glyoxylate and dicarboxylate metabolism, tryptophan metabolism, steroid hormone biosynthesis, glycolysis. Through the analysis of the protein interactions, there were some proteins in the protein interaction nodes, such as Cytochrome P4503A1, Cytochrome P450 2C55,Glutathione S-transferase alpha-5, Glutathione S-transferase alpha-2, Glutathione S-transferase P,proliferating cell nuclear antigen, Mitogen-activated protein kinase 3, Alpha-2-HS-glycoprotein, Cyclin-dependent kinase 4, Alpha-1-macroglobulin, Aldose reductase, Fibrinogen beta chain Precurspr, and so on.CONCLUSION:Cyclin-dependent kinase4, Alpha-1-macroglobulin, Alpha-2-HS-glycoprotein, Mitogen-activated protein kinase 3 and Carboxylesterases-2c. According to the above proteins, their expression is associated with cancer. And they play an important role in protein interaction simultaneously.So they may be the critical proteins in fibrosis-carcinoma. In addition, differentially expressed proteins take a high proportion in PI3K-Akt signaling pathway and metabolism of xenobiotics by cytochrome P450, the two pathways may be pivotal in regulatory pathways of fibrosis-carcinoma.