Hierarchical network modulation of cell death regulators and inflammatory genes by biogenically engineered gold nanoconstructs with CK in gastric tumorigenesis

Gastric cancer (GC) progression is influenced through the dysregulation of the cell death and chronic inflammation, which together foster a tumor-promoting microenvironment and enhance cancer cell survival. Targeting these pathways could provide novel therapeutic strategies. In a previous study, we synthesized gold nanoparticles (GNPs) using Bifidobacterium animalis subsp. lactis (BAL) and compound K (CK), leading to the creation of BAL-CK-GNPs. This study aims to investigate the anti-gastric cancer potential of BAL-CK-GNPs against three cancer cell lines, including A549, HT-29, and AGS cells. Our findings demonstrated that BAL-CK-GNPs exerted the highest inhibitory effect (IC50 = 43.72 μg/mL) on AGS cells. We confirmed their cellular uptake and penetration using enhanced dark field microscopy and assessed apoptosis induction through Hoechst and PI staining. Apoptotic effects were further supported by mitochondrial disruption, visualized with Mito-tracker staining, and transmission electron microscopy, which revealed the cellular localization of BAL-CK-GNPs. Therefore, gene expression analysis revealed the upregulation of apoptotic markers, supporting apoptosis induction. Subsequent transcriptomics analysis identified significant changes in differentially expressed genes (DEGs), with BAL-CK-GNPs treatment suppressing 78 and stimulating 146. Notably, these included glutathione metabolism pathways, as well as cell death pathways (ferroptosis and necroptosis) and inflammatory pathways (NF-KB, IL-17, TNF, chemokines, and cytokines). Among these DEGs, eight key regulators (IFI35, DDX58, IFIT1, ISG15, EIF2AK2, IFIH1, FLT3LG, and IRF7) associated with cell death and inflammation were prominently affected, suggesting their roles in mediating the therapeutic effects of BAL-CK-GNPs. Our findings suggest that BAL-CK-GNPs represent a promising therapeutic strategy for GC, capable of inducing apoptosis, ferroptosis, necroptosis, and modulating inflammation to inhibit GC cell growth.