Abstract
Gastric cancer is the fifth most common cancer and the third leading cause of cancer-related mortality globally. Abnormal DNA methylation is closely related to gastric cancer. The purpose of the study was to investigate the methylation of the SYNE1 and MAGI2 gene promoter and its relationship with the clinical-pathological factors, chemotherapy efficacy, and survival, thus providing a new biomarker for the prognosis and chemotherapy efficacy in gastric cancer.The methylation status of SYNE1 and MAGI2 in gastric cancer and adjacent tissues was detected by MSP method in 70 cases of advanced gastric cancer paraffin specimens.The methylation rate of the SYNE1 and MAGI2 gene promoter region was higher in gastric cancer tissues compared with adjacent tissues. The methylation status of SYNE1 was associated with the age at diagnosis and the size of the primary tumors, but no clinical or pathological factors have been found to be related with the methylation status of MAGI2 promoter. A high level of SYNE1 promoter methylation was associated with poorer chemotherapy efficacy in recurrent patients with gastric cancer. Thirty-three percent of the 70 patients exhibited highly methylated MAGI2; in this group, the median progression-free survival time was 4.1 months, shorter than those with negative methylated MAGI2 whose PFS was 5.1 months.MAGI2 is more methylated in gastric cancer than in adjacent tissues suggesting that hypermethylation changes in MAGI2 may be one of the mechanisms of tumorigenesis in gastric cancer. The methylation status of the SYNE1 and MAGI2 promoter regions may affect the chemotherapy efficacy of advanced gastric cancer. The prognosis of MAGI2-negative patients was better than that of positive ones, suggesting that MAGI2 may be an independent prognostic factor for PFS in patients with advanced gastric cancer.