Analysis of Low-Abundance Differential Proteins in Plasma from Hepatocellular Carcinomas Patients by Multidimensional Chromatography-Tandem Mass Spectrometry

In this study, a novel multidimensional separation technique was developed to analyze differential plasma proteins of immunodepleted plasma in five patients with hepatocellular carcinomas (HCC), and mixed plasma of five healthy volunteers was used as control. Samples of human plasma were depleted to six most abundance proteins using an immunoaffinity chromatography Agilent MARS Spin Cartridge and then were separated under the preferred conditions by reversed phase LC. Overexpressed differential fraction of low-abundance proteins were collected and trypsined, and then the trypsined peptides were enriched and fractioned and indentified using HPLC-CHIP/MS. Reversed phase high-performance liquid chromatographic prefraction of immunodepleted human plasma coupled with HPLC-CHIP/MS was used to enhance mass spectrometry identification of low-abundance proteins, and about 27 kinds of proteins were identified. Twenty-three kinds of protein are related to various diseases or tumors, and among them, IMP3, ARNT2, and GRIP1 may prove to be potential biomarkers for the diagnosis of HCC.