LAUSR

Background Gastric tumor (GT) is associated with high morbidity and mortality, with surgery among the most effective treatment methods. Accurate interoperative determination of the tumor margin is crucial. Methods In this study, using internal extractive electrospray ionization-MS, mass spectral data of GT and gastric normal (GN) tissues from 36 patients were collected. Results In positive ion detection mode, the relative abundances of m/z 132, 147, 170, and 175 were increased, while the relative abundances of m/z 55, 83, 154, and 203 were decreased in GT tissue. Using partial least squares analysis, the mass spectral data of GT and GN tissues were discriminated, and differential ions (P≤0.01), including m/z 55, 83, 154, 170, and 203, were obtained from loading plots. After receiver operating characteristic curve analysis, peaks at m/z 83 and 203 showed high accuracy for distinguishing GT from GN tissue. These two peaks were then preliminarily attributed to 5-aminoimidazole and serylproline, respectively, which might be useful molecular biomarkers associated with GT development. Conclusion Further investigations of the functions of 5-aminoimidazole and serylproline might provide a better understanding of the underlying mechanisms involved in GT.