Alteration and significance of protein expression profile in gastric cancer with preoperative conformal radiation therapy

AIM: To investigate the alteration and significance of the protein expression profile in gastric cancer with preoperative conformal radiation therapy. METHODS: The pathologically-diagnosed gastric cancer patients were randomly chosen to perform conformal radiation therapy before operation. The patients without conformal radiation treatment served as controls. The tumor tissues were collected after operation from the patients. The alteration of the protein expression profile was detected by 2-dimensional electrophoresis and MALDI-TOF-MS. The expression of vascular endothelial growth factor (VEGF), c-erbB-2 and epidermal growth factor receptor (EGFR) was detected by RT-PCR and Western blotting. RESULTS: Compared with the patients without conformal radiation therapy, the protein expression profile of tumor tissues from gastric cancer patients with conformal radiation therapy was obviously altered. The expression of VEGF, c-erbB-2 and EGFR was differentially reduced (P<0.01). CONCLUSION: The preoperative accurate conformal radiation therapy reduces the expression of gastric cancer-related epithelial proteins, indicating new therapeutic targets for gastric cancer.