TIPE2 inhibits GC via regulation of cell proliferation, apoptosis and inflammation

Gastric cancer (GC), a type of gastric mucosal epithelium disease caused by common malignant tumors, has become a major threat to human health and survival. Tumor necrosis factor-α-induced protein-8 like-2 (TIPE2) is a negative immune regulatory factor that is selectively expressed in immune organs, immune cells and various epithelial cells and serves an important role in the maintenance of human physiological immune homeostasis. In our preliminary study, we found that the expression of TIPE2 was downregulated or absent in GC tissues compared with normal gastric mucosa tissues, indicating that TIPE2 may play a significant role in the development of GC. To clarify the role of TIPE2 in the progression of human GC and to elucidate the underlying mechanism, the association between TIPE2 and phosphatidylinositol 3-kinase (PI3K)/AKT, the cell cycle, the caspase-related apoptosis pathway and the NF-κB signaling pathway were investigated through western blot and flow cytometric analysis. It was determined that TIPE2 inhibited GC cell proliferation mainly by reducing the expression of phosphorylated AKT and ERK, which caused subsequent inhibition of the PI3K-AKT and Ras-Raf-MEK-ERK1/2 signaling pathways. Additionally, we investigated the relationship between TIPE2 and GC and discovered that TIPE2 inhibited tumor progression via growth, apoptosis and inflammatory pathways. The results of the present study provided a theoretical basis for the development and application of TIPE2 as an antitumor agent.