Systems toxicology unravels multi-tiered carcinogenic networks of zearalenone in gastric cancer.

[INTRODUCTION] Gastric cancer (GC) is a leading cause of cancer mortality worldwide, and dietary factors like mycotoxins play a significant role in its etiology. Zearalenone (ZEN), a widespread grain contaminant, is a suspected carcinogen; however, its molecular mechanisms in GC remain unclear. This study used an integrated systems toxicology approach to identify key targets and pathways of ZEN-induced GC and validate the findings.

[METHODS] An integrated computational and experimental strategy was used. GC-related genes were identified from Gene Expression Omnibus (GEO) datasets using differential expression and weighted gene co-expression network analysis (WGCNA). ZEN targets were obtained from multiple databases. Common targets were analyzed for pathway enrichment and protein-protein interactions. Eleven machine learning algorithms screened for core driver genes among these common targets. The binding stability of ZEN to core targets was assessed using molecular docking and 100-ns molecular dynamics simulations. In vitro functional validation was performed using CCK-8, colony formation, EdU, and wound healing assays on the human GC cell line MKN-45.

[RESULTS] We identified 157 common targets of ZEN and GC. Enrichment analysis highlighted key pathways, including P13K-Akt signaling and glycolysis. Machine learning identified six core driver genes (COL1A1, INHBA, PKM2, THBS2, MFAP2, and CPA2) with high diagnostic potential (AUC>0.85). Molecular simulations confirmed ZEN forms stable complexes with core targets, particularly PKM2 and THBS2. In vitro experiments showed low concentrations of ZEN (40-80 nM) significantly promoted proliferation and migration of MKN-45 cells, demonstrating a hormetic effect.

[DISCUSSION] This study suggests ZEN promotes GC progression through a multi-level network. ZEN may directly modulate key effector proteins such as PKM2 to induce metabolic reprogramming. The observed hormetic pro-proliferative and pro-migratory responses were linked to the pre-existing activation state of the PI3K/Akt pathway. These findings provide novel mechanistic insights into the carcinogenic risk of ZEN.