Abstract
Stomach cancer is the second largest cause of cancer-related mortality globally, and it continues to be a reason for worry today. Inhalation of the stomach cancer risk factor H. pylori produces large levels of reactive oxygen species (ROS). When combined with glutathione reductase, glutathione peroxidase 3 (GPX3) catalyzes the reduction of hydrogen peroxide and lipid peroxides. To get a better understanding of the GPX3 gene's role in the illness, the researchers used quantitative real-time RT-PCR to examine the gene's expression and regulation in gastric cancer cell lines, original gastric cancer samples, and 45 normal stomach mucosa adjacent to malignancies. According to the research, GPX3 expression was decreased or silenced in eight of nine cancer cell lines and 83 percent of gastric cancer samples (90/108) as compared to normal gastric tissues in the vicinity of the tumor (P < 0.0001). It was found that 60 percent of stomach cancer samples exhibited DNA hypermethylation after analyzing the GPX3 promoter (P=0.007) (a methylation level of more than 10 percent, as measured by bisulfite pyrosequencing). In stomach tumors, we found a statistically significant reduction in the amount of GPX3 DNA copies (P < 0.001). The gene expression of SNU1 and MKN28 cells was restored after treatment with 5-Aza-2' Deoxycytidine to reduce GPX3 promoter methylation. Genetic and epigenetic alterations lead GPX3 to be dysfunctional in gastric cancer. This indicates that the systems that regulate ROS have been disrupted, and GPX3 may be implicated in the development of gastric cancer, as shown by our results when evaluated alone and in combination.