Integrated In silico and 3D Spheroid Models Reveal Key Genes and MiRNAs Driving Cisplatin/5-FU Resistance and Metastatic Potential in Gastric Cancer

Background : Gastric cancer is a leading cause of cancer mortality worldwide, driven largely by chemotherapy resistance and metastasis. Cisplatin and 5-fluorouracil are common first-line agents, but tumor adaptation limits long-term efficacy; the combined role of microRNAs in resistance and metastasis remains unclear. Methods : We integrated bioinformatics analysis of GEO dataset GSE14210 with STRING network and miRNA prediction, and validated findings in MKN-45 and patient-derived 3D spheroid models exposed to cisplatin and 5-FU. Gene and miRNA expressions were assessed in metastatic versus non-metastatic tumor tissues and treated versus untreated spheroids. Results : We identified 414 upregulated DEGs, including 56 hubs (degree ≥10) and 21 hubs upregulated in tumors. Patterns of co-expression among CXCL8, CCL5, MMP9, STAT1 and miR-17-5p/miR-24-3p/miR-124-3p/miR-145-5p were consistently associated with resistance and metastatic features (p<0.05). MKN-45 spheroids showed post-treatment regrowth, whereas patient-derived spheroids did not recover ≥80% baseline under identical exposure. Conclusion : These findings highlight coordinated gene–miRNA expression patterns linked to chemotherapy resistance and metastasis in gastric cancer and support their further evaluation as candidate biomarkers and therapeutic targets.