Granzyme B Promotes Proliferation, Migration and EMT Process in Gastric Cancer

Granzyme B (GZMB), a critical member of the Gr gene family, is known to play an essential role in diverse physiological and pathological processes such as inflammation, acute and chronic inflammatory diseases, and cancer progression. In this study, we delve deeper into the role of GZMB within the context of gastric cancer (GC) to examine its expression patterns and functional implications. To accomplish this, we applied a combination of quantitative real-time polymerase chain reaction, western blotting, and immunohistochemistry techniques. These methodologies allowed us to accurately gauge GZMB expression levels in GC tissues and investigate their correlation with various clinical-pathological variables. Our secondary focus was to discern the regulatory influence of GZMB on GC cell biology. We used an array of assays including cell counting kit-8 (CCK-8), colony formation, 5-ethynyl-2'-deoxyuridine, and migration assays. The effect of GZMB on gastric cancer progression was further validated through a subcutaneous xenograft mouse model. Our findings underscored that GZMB mRNA and protein levels were upregulated in GC tissues, a feature that showed a significant correlation with GC staging. We also discovered that a decrease in GZMB expression via knockdown experiments suppressed the proliferation and migration capabilities of GC cells. This effect was manifested through diminished expression levels of epithelial-mesenchymal transition (EMT) markers. In stark contrast, the overexpression of GZMB through plasmid transfection appeared to enhance the proliferation and migration abilities of GC cells. This was coupled with an upregulation in EMT expression. Our study concludes by emphasizing that GZMB promotes the growth, migration, and EMT processes in gastric cancer. In vitro, cell-based experiments and in vivo xenograft mouse models confirm this. Our findings provide a more comprehensive understanding of GZMB's role in gastric cancer pathogenesis, potentially opening doors for novel therapeutic strategies targeting this molecular pathway.