NOD2 inhibits the proliferation of esophageal adenocarcinoma cells through autophagy

AIM: To study the regulatory mechanism of NOD2 in the inhibition of esophageal adenocarcinoma cell proliferation. METHODS: Cell experiments: after confirming the decrease in NOD2 expression in esophageal adenocarcinoma, we overexpressed NOD2 in esophageal adenocarcinoma cells via lentivirus, compared and verified the changes in esophageal adenocarcinoma cell proliferation before and after NOD2 overexpression, and compared the overexpression group with the control group by mRNA sequencing to identify pathways that may affect cell proliferation. Then, the autophagy level of multiple groups were assessed, and the results were verified by rescue experiments. In vivo experiments: we administered esophageal adenocarcinoma cells to nude mice to form tumors under their skin and then injected the tumors with NOD2 overexpression lentivirus and negative control lentivirus. After a period of time, the growth curve of the tumor was generated, and the tumor was removed to generate sections. Ki67 was labeled with immunohistochemistry to verify cell proliferation, and the protein was extracted from the tissue to detect the molecular indices of the corresponding pathway. RESULTS: Upregulation of NOD2 expression inhibited the proliferation of esophageal adenocarcinoma cells. Upregulation of NOD2 expression increased the autophagy level of esophageal adenocarcinoma cells via ATG16L1. After ATG16L1 was inhibited, NOD2 had no significant effect on autophagy and proliferation of esophageal adenocarcinoma cells. Enhanced autophagy in esophageal adenocarcinoma cell lines inhibited cell proliferation. In vivo, the upregulation of NOD2 expression improved the autophagy level of tumor tissue and inhibited cells proliferation. CONCLUSION: NOD2 can activate autophagy in esophageal adenocarcinoma cells through the ATG16L1 pathway and inhibit cell proliferation.