Adverse Outcome Pathway 298: Increase in Reactive Oxygen Species Leading to Human Treatment-Resistant Gastric Cancer.

Injury causes resistance in human gastric cancer. Adverse Outcome Pathway (AOP) 298, entitled "increase in reactive oxygen species (ROS) leading to human treatment-resistant gastric cancer," consists of "increase in ROS" as a molecular initiating event (MIE), followed by a series of key events (KEs), namely "porcupine-induced Wnt secretion and Wnt signaling activation," "beta-catenin activation," and "epithelial-mesenchymal transition (EMT)," and the adverse outcome (AO) of "treatment-resistant gastric cancer" in the sequence. AOP 298 includes four KE relationships (KERs): "increase in ROS leads to porcupine-induced Wnt secretion and Wnt signaling activation," "porcupine-induced Wnt secretion and Wnt signaling activation leads to beta-catenin activation," "beta-catenin activation leads to EMT," and "EMT leads to treatment-resistant gastric cancer." ROS has multiple roles in disease, such as in the development and progression of cancer, or apoptotic induction, causing anti-tumor effects. Regarding AOP 298, we focus on the role of sustained chronic ROS levels in inducing therapy resistance in human gastric cancer. EMT, induced by Wnt/beta-catenin signaling, demonstrates cancer stem cell-like characteristics in human gastric cancer.