STAM2 knockdown inhibits proliferation, migration, and invasion by affecting the JAK2/STAT3 signaling pathway in gastric cancer.

Signal transducing adaptor molecule 2 (STAM2) is a phosphotyrosine protein, which regulates receptor signaling and trafficking of mammalian cells. However, its role in gastric cancer (GC) remains undiscovered. In this study, we aimed to investigate the functions of STAM2 in GC. The mRNA and protein expression levels of STAM2 were measured by quantitative real-time PCR, western blot analysis, and immunohistochemistry. STAM2 was stably silenced in AGS and HGC-27 cells using small interfering RNA. The function of STAM2 in GC cells was further investigated by CCK-8 assay, EdU incorporation assay, flow cytometry, and scratch wound healing and Boyden chamber assays. Additionally, we conducted biological pathway enrichment analysis and rescue assays to explore the effects of STAM2 on JAK/STAT signaling pathway. Our results showed that STAM2 is remarkably highly expressed in GC tissues and cells, and overexpressed STAM2 is correlated with tumor size, advanced tumor node metastasis stage, and poor prognosis. In addition, STAM2 knockdown could significantly inhibit proliferation, block cell cycle, and restrain migration and invasion capabilities of GC cells. Mechanistically, we found that STAM2 knockdown effectively decreased the expressions of MMP2 and MMP9 and the phosphorylation levels of JAK2 and STAT3. Taken together, this study revealed that STAM2 knockdown could suppress malignant process by targeting the JAK2/STAT3 signaling pathway in GC.