Gastrokine 1 transferred by gastric cancer exosomes inhibits growth and invasion of gastric cancer cells in vitro and in vivo.

In gastric cancer, gastrokine 1 (GKN1) is a potential theragnostic marker while the related mechanisms remain elusive. Exosomes mediate intercellular communications via transferring various molecules, yet there are limited research studies on the specific cargos of gastric cancer exosomes and the associated mechanisms in this disease. In the present study, AGS and N87-C cells were transfected with an overexpressed GKN1 plasmid, followed by extraction of exosomes. The study utilized gastric cancer cell lines and a xenograft mouse model to investigate the functional significance of exosomal GKN1. Cell proliferation, metastasis, and apoptosis were assessed through CCK-8, Transwell, and flow cytometry assays, respectively. The study further explored the mechanism of exosomal GKN1 and its interaction with the PI3K/AKT/mTOR signaling pathways, including immunofluorescence and western blot analyses. Exosomal GKN1 was observed to suppress cell proliferation and invasion while enhancing apoptosis. This effect was attributed to the modulation of key proteins involved in cellular processes, including Ki-67, MMP-9, Bcl-2, Bax, caspase-3, and caspase-9, ultimately impacting the PI3K/AKT/mTOR signaling pathway. The findings suggest that exosomal GKN1 exerts inhibitory effects on gastric cancer cell growth and invasion through the regulation of the PI3K/AKT/mTOR signaling cascade, both in experimental cell cultures and animal models.