Ras GTPase-Activating Protein-Binding Protein 1 Affected the Proliferation, Apoptosis, and Oxidative Stress Damage of Gastric Cancer Cells by Regulating the Methylation Level of the Vezatin DNA

Abstract

Background: Gastric cancer (GC) is a prevalent malignancy of the digestive tract, posing substantial challenges and serious threats to human life. The crucial roles of Ras GTPase-activating protein-binding protein 1 (G3BP1) as an enhancer and Vezatin (VEZT) as a suppressor of cancer progression have been recognized. Therefore, this study aimed to elucidate the molecular mechanisms underlying the role of G3BP1/VEZT in GC cell activity and the consequent oxidative stress damage. Methods: The expression levels of G3BP1 and VEZT in GC cells were assessed utilizing Quantitative Reverse Transcription Polymerase Chain Reaction (qRT-PCR) and western blot assays. Subsequently, both G3BP1 and VEZT were knocked down in GC cells and their efficiency was evaluated using qRT-PCR. Additionally, methylation levels of the VEZT gene were evaluated using pyrosequencing technology. Moreover, DNA Methyltransferase 1 (DNMT1) enzyme activity, as well as levels of Reactive Oxygen Species (ROS), Malondialdehyde (MDA), 4-Hydroxynonenal (4-HNE), and Iron were assessed in GC cells utilizing Enzyme-Linked Immunosorbent Assay (ELISA). Furthermore, the proliferation activity and apoptosis levels of GC cells were determined by the Cell Counting Kit-8 (CCK-8) assay and flow cytometry. Results: G3BP1 was upregulated and VEZT was downregulated in GC (p < 0.01, and p < 0.001). The knockdown of G3BP1 (si-G3BP1) led to a decrease in VEZ-silencing-induced DNA methylation level and DNMT1 activity (p < 0.05, and p < 0.01). The si-G3BP1 reversed the enhanced cell viability, decreased apoptosis rate, and decreased levels of ROS, MDA, and 4-HNE in GC cells induced by VEZT silencing (p < 0.01, and p < 0.001). Moreover, si-G3BP1 also reversed the elevation of Thioredoxin-dependent peroxide reductase (T-SOD), Glutathione (GSH), and Glutathione Peroxidase 4 (GPx4) levels induced by si-VEZT (p < 0.05, p < 0.01, and p < 0.001). Conclusion: Our study confirms the aberrant activation of G3BP1 and the suppression of VEZT in GC. Furthermore, we observed that G3BP1 affects the proliferation, apoptosis, oxidative stress-induced damage, and iron damage of GC cells by regulating the methylation level of VEZT.