Identification of specific serum biomarkers in gastric adenocarcinoma patients

AIM: To screen the possible serum biomarkers for the diagnosis of gastric adenocarcinoma.METHODS: The surface-enhanced laser desorption ionization time-of-flight mass spectrometry(SELDI-TOF-MS) was used to screen the serum samples from 109 cases of gastric adenocarcinoma and 106 control subjects(60 healthy subjects,30 patients with chronic superficial gastritis and 16 cases of chronic atrophic gastritis).The differentially-expressed protein peaks were selected and isolated with high-performance liquid chromatography(HPLC),and processed with enzyme before liquid chromatography-mass spectrometry tandem mass spectrometry(LC-MS/MS) analysis.The data mining was performed with software Xcalibur program component Bioworks 3.2.RESULTS: Three differentially-expressed protein peaks were selected as potential serum biomarkers of gastric adenocarcinoma patients.The m/z peak at 5 906.5 showed the increase(8.53±4.33 in cancer group,and 0.88±0.31 in control group).The m/z peaks at 6 635.7 and 8 716.3 showed the decrease(6.54±2.44 and 0.93 ± 0.29,respectively,in cancer group and 17.56±4.43 and 2.16±0.98,respectively,in control group,P0.01).The 3 m/z peaks were identified as fibrinogen α-chain,apolipoprotein A-II and apolipoprotein CI,respectively.The combined use of the 3 biomarkers distinguished the samples in the cancer patients out of the controls at a sensitivity of 93.85%(61/65) and a specificity of 94.34%(50/53).CONCLUSION: The fibrinogen α-chain,apolipoprotein A-II and apolipoprotein CI identified as potential markers for gastric adenocarcinoma show diagnostic values in clinical application.