Exploring the Molecular Mechanism of 1,25(OH)(2)D(3) Reversal of Sorafenib Resistance in Hepatocellular Carcinoma Based on Network Pharmacology and Experimental Validation.

Sorafenib is currently the first-line therapeutic agent for advanced hepatocellular carcinoma (HCC). However, sorafenib resistance remains a major clinical challenge. Studies have reported that 1,25-dihydroxyvitamin D3 (1,25(OH)(2)D(3)) can synergize with multiple chemotherapeutic drugs to enhance their antitumor efficacy, but the combinatorial effect between 1,25(OH)(2)D(3) and sorafenib has not yet been investigated. This study aimed to investigate the potential molecular mechanism by which 1,25(OH)(2)D(3) reverses sorafenib resistance in hepatocellular carcinoma using network pharmacology, molecular docking, and experimental validation. We predicted a web-based pharmacological approach to predict potential targets of 1,25(OH)(2)D(3) and its derivatives, as well as sorafenib resistance genes in hepatocellular carcinoma from public databases. We then constructed 1,25(OH)(2)D(3) chemo-sensitizing expression profiles through intersection analysis. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were employed to predict the potential pathways involved in 1,25(OH)(2)D(3) chemosensitization, followed by molecular docking analysis and analysis of molecular dynamics simulations. Finally, experimental validation were conducted to elucidate the potential mechanisms by which 1,25(OH)(2)D(3) enhances the sensitivity of HCC to sorafenib. Compound and target screening identified 730 predicted targets of 1,25(OH)(2)D(3) and its derivatives, 1144 genes associated with sorafenib resistance in hepatocellular carcinoma, and 56 potential chemosensitization targets from the intersection analysis. KEGG analysis suggested that the chemosensitization effect of 1,25(OH)(2)D(3) might be mediated by the FoxO signaling pathway. Molecular docking showed that both 1,25(OH)(2)D(3) and its derivatives could stably bind to FOXO3A, a key gene in the FoxO family, and molecular dynamics simulation analysis further indicated that the two bind well together. In vitro experiments demonstrated the synergistic effects of 1,25(OH)(2)D(3) and sorafenib, significantly inhibiting the viability and colony formation rate of sorafenib-resistant hepatocellular carcinoma cells. Additionally, the combination treatment promoted apoptosis and inhibited autophagy. Furthermore, the combination modulated the FOXO3A/FOXM1 signaling axis. This study reveals that 1,25(OH)(2)D(3) enhances the chemosensitivity of hepatocellular carcinoma (HCC) to sorafenib, with underlying mechanisms potentially involving the targeted modulation of the FOXO3A/FOXM1 signaling axis and the reversal of sorafenib-resistant phenotypes through the regulation of apoptotic and autophagic pathways.