Helicobacter pylori (H. pylori) has been identified as a type I carcinogen and contributes to a high rate of gastric cancer (GC), especially in Eastern Asia. Extracellular vesicles (EVs) have the potential to be used to detect various cancer types and diseases. However, the protein markers in EVs for the prognosis of H. pylori infection and GC are unknown. We aim to identify the proteins within EVs derived from a gastric epithelial cell line (AGS) infected with H. pylori by using LC-MS/MS.
EVs were isolated from AGS cells infected with high- and low-virulence H. pylori (strains TN2wt and Tx30a) by ultracentrifugation. Proteins within these EVs were identified and analyzed for potential marker candidates through bioinformatics. Proteins in H. pylori-derived EVs (HpEVs) from bacterial culture supernatant and HpEVs derived from H. pylori-infected AGS cells were elucidated.
Differentially expressed proteins by proteomic analysis in AGSEVs-Tx30a vs. AGSEVs-noninfected (NI) and AGSEVs-TN2wt vs. AGSEVs-NI were 107 and 55 proteins, respectively. Bioinformatics of these proteomes revealed that essential proteins for H. pylori survival and pathogenicity including outer membrane proteins, metabolism-related, host cell infection-related, and virulence-related proteins were observed in HpEVs. Interestingly, EVs derived from AGS cells infected with H. pylori TN2wt significantly contained multiple proteins related to GC (ATP6V0A1, GAPDH, HINT1, LYZ, and RBX1).
This study provides a comprehensive protein profile of EVs from H. pylori-infected AGS cells and HpEVs, which could serve as liquid-based biomarkers in the future for screening H. pylori infection, especially GC-related.