Introduction: Gastric cancer occurred in China and even the whole East Asia with high incidence. The objective of this study was to investigate the role of IL-17  in gastric cancer cells mediated by LCN2  binding to SLPI .
Methods: The expression of LCN2  and SPLI  in gastric cancer cells and transfection effects were confirmed by RT-qPCR analysis. The proliferation, clone formation ability, invasion, migration, apoptosis, and cell cycle of gastric cancer cells were in turn detected by CCK-8 assay, clone formation assay, transwell assay, wound healing assay, and flow cytometry analysis. The combination between LCN2  and SLPI  was determined by co-immunoprecipitation assay. The expression of Caspase-3, Bcl-2, cyclinB1, cyclinD1, MMP9, and SLPI  in gastric cancer cells was detected by Western blot analysis.
Results: LCN2  and SPLI  exhibited the highest levels in AGS cells, and thus AGS cells were selected for the next experiments. Down-regulation of LCN2  suppressed the proliferation and clone formation ability of AGS cells treated with IL-17 . IL-17  promoted the invasion and migration of AGS cells, which was partially reversed by the down-regulation of LCN2 . Down-regulation of LCN2  mediated by IL-17  promoted apoptosis and suppressed the cell cycle of AGS cells.
Discussion: Down-regulation of LCN2  mediated by IL-17  suppressed the proliferation and suppressed the migration and invasion and cell cycle of gastric cancer cells by targeting SLPI .
Keywords: lipocalin-2, LCN2, interleukin-17, IL-17, gastric cancer cells, SLPI