Two-dimensional differential in-gel electrophoresis for identification of gastric cancer-specific protein markers

Abstract

Gastric cancer is the second most common fatal malignancy in the world. Proteomics studies of clinical tumor samples have led to the identification of specific protein markers of gastric cancer detection and better understanding the carcinogenesis of gastric cancer. Gastric cancer tissue of epithelial origin and adjacent normal mucosa were examined in pair by fluorescence 2-D differential in-gel electrophoresis proteomics analysis utilizing 2-D PAGE protein separation. Intensity changes of 33 spots were detected with statistical significance. Twenty-two out of the 33 spots were identified by MALDI-TOF MS or MS/MS. Of the 9 up-regulated proteins, 7 were identified, including heat shock protein 60 (HSP60), mutant desmin, effector cell proteinase receptor 1 splice form 1b, hypothetical protein, unnamed protein product, and manganese superoxide dismutase (MnSOD), a protein similar to α-actin. Of the 20 down-regulated proteins, 16 were identified, including selenium binding protein 1, fibrinogen γ, HSP27, tubulin α 6, zinc finger protein 160, prostaglandin F synthase, and eukaryotic translation elongation factor 1 α 1. Our results suggest that MnSOD may be a potential serum marker for molecular diagnosis of gastric carcinoma, and DIGE is a useful technique for screening differentially expressed proteins in cancer tissues.