The Screening And Identification Of Human Gastric Cancer Associated Antigens By Serologic Proteomae Analysis (SERPA)

OBJECTIVE:Gastric cancer is the most common gastrointestinal cancer, which is NO.2 cause of cancer death and about 640,000 people died of it each year. It is seriously threat to people's health and lives, but so far its canceration mechanism is unclear. Therefore, it has important theoretical and practical significance that search and found tumor marker of gastric cancer. This study was to screen and identify human gastric carcinoma-associated antigens with two-dimensional electrophoresis, immunoblotting and MALDI-TOF-MS, which could be one method of screening of tumor-associated antigen.METHODS:Collected 15 cases of gastric tumor tissue and serum of patients, which divided into 3 groups randomly. Total protein were isolated by 2-dimensional electrophoresis(2-DE). Three pieces of gum at the same time to run each sample, one piece after Coomassie stained gel as a parallel, the other two respectively done western blot with gastric cancer and non-cancer patient's own serum as an anti-human serum after transfer film, establish 2DE/Western blot reaction patterns. The immunoblotting imaging films were obtained and the differential reacting protein spots were recognized. Then the differential reacting proteins were obtained in the replica gel by matching analysis, and identified by peptide mass fingerprint (PMF) based on matrix-assisted laser desorption/ ionization time of flight mass spectrometry (MALDI-TOF-MS) and database searching.RESULTS:The results obtained well-resolved and well-reproducible 2-DE maps of total protein of human gastric cancer tissues. The number of average spots of 3 gels was 789士27. The number of average match point was 684士21. The average match rate was 86.7%. Well-resolved 2DE/Western blot reaction patterns were obtained with gastric cancer and non-cancer patient's own serum as an anti-human serum. Nineteen differentially expressed proteins were found. Of the 19 proteins,11 were identified as human gastric carcinoma-associated antigens. Nine proteins, Desmin (DES), Vimentin(VIM), Tubulin(TUBB), Heat Shock Protein 5(HSPA5), ACTC1 Actin alpha, Immunoglobulin heavy chain constant regionγ1(IGHG1), Phosphoglycerate kinasel(PGK1), ACTA2 Actin aortic and Transgelin(TAGLN,SM22-a) were up-regulated and two, pyruvate kinase M2(PKM2), ALB Isoform 2 of Serum, down-regulated.CONCLUSIONS:The results obtained well-resolved 2DE/Western blot reaction patterns. Eleven human gastric carcinoma-associated antigens were found by SERPA. The results provide foundation for screening molecular biomarkers of gastric cancer.