Identification of 14-3-3ζ as a potential biomarker in gastric cancer by proteomics-based analysis

The identification of tumor biomarkers to support early diagnosis and tumor progression monitoring may potentially reduce the mortality of gastric cancer (GC). The present study aimed to detect novel tumor-associated antigens from the AGS GC cell line, and to identify their associated autoantibodies in sera from patients with GC by proteomics-based approaches. Proteins from AGS cell lysates were isolated using two-dimensional polyacrylamide gel electrophoresis, and western blotting was subsequently performed, to determine autoantibody responses in sera derived from patients with GC and healthy individuals. Positive protein spots were removed from gels stained with Coomassie blue, and were then evaluated by liquid chromatography-tandem mass spectrometry. Sera from patients with GC produced numerous spots, one of which was identified as 14-3-3 zeta. Autoantibody frequency to 14-3-3 zeta was 17.6% (15/85) in patients with GC, which was significantly higher than that in healthy control individuals (2.4%; 2/85; P < 0.01). These results suggested that the autoantibody against 14-3-3 zeta may be a potential serological biomarker for the detection and diagnosis of GC.