雜環胺類化合物之分析方法開發與其生化作用機制之探討(3/3)

IQ (2-amino-3-methyl-3H-imidazo[4,5-F]quinoline), belonged to heterocyclic amine (HCA) family, is classified as a probable human carcinogen (class 2A) by the International Agency for Research on Cancer (IARC). Studies to date indicate that IQ is carcinogenic to animals, especially in liver. Still, the mechanism of HCA-induced cancer in protein level is not well-understood. In this study, isobaric tags for relative and absolute quantitation (iTRAQ) technology was applied for the investigation of the HepG2 protein profiles with different IQ-treat times. In order to obtain higher complementarity, orthogonality and more protein identifications, two-dimensional separation techniques were used as fractionation strategies for the iTRAQ labeled peptides, including solution isoelectric focusing (sIEF), basic reverse phase chromatography (bRP), and strong cationic exchange chromatography (SCX). Protein identification and quantitation was then accomplished by liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis. A total of 10712 unique peptides and 3057 proteins was successfully identified. Among these three fractionation strategies, bRP fractionation gave the most protein and unique peptide identifications. Moreover, 271 differentially expressed proteins were selected and found to be highly associated with ribosome, proteasome, spliceosome, Parkinson’s disease. Some of these differential genes (Ribosome- RPS26、RPS4X、RPL37A、RPS24，Parkinson’s disease-SLC25A4、NDUFA8) were confirmed and validated using qRT-PCR.