Utilized mass spectrometry-based protein profiling system to identify potential biomarkers of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common malignant liver tumor. The purpose of this study is to characterize proteins secreted from the HepG2 cells, which may relate to cell differentiation and tumor metastasis. In the proteomic analysis, the secretome was identified by nano-high–performance liquid chromatography/electrospray ionization tandem mass spectrometry (nano-HPLC/ESIMS/MS) followed by peptide fragmentation pattern analysis. In this study, three proteins, p130Cas-associated protein (p130Cas/BCAR1), TAR DNA-binding protein 43 (TDP43/TARDBP) and translationally controlled tumor protein (TCTP/TPT1), were identified and confirmed by Western blotting, which showed significantly differential expression compared with the normal liver cells. Analyzing differential protein expressions in HepG2 cell by proteomic approaches suggests that p130Cas/BCAR1, TDP43/TARDBP and TCTP/TPT1 as key proteins and may serve as biomarkers for HCC.