Integrating network toxicology with multi-omics approaches to elucidate molecular targets and pathway mechanisms in BPA-induced hepatocellular carcinoma.

Bisphenol A (BPA), an environmental endocrine disruptor, is implicated in hepatocellular carcinoma (HCC), but its molecular mechanisms are unclear. This study employed an integrative computational framework to identify potential BPA-related molecular targets in HCC, assess their statistical clinical value, and generate hypotheses regarding their roles within the tumor microenvironment. BPA and HCC targets were retrieved from public databases and intersected with differentially expressed genes in HCC, identifying fifteen overlapping genes statistically enriched in cell cycle regulation, p53 signaling, and viral carcinogenesis. Six hub genes (MKI67, CCNA2, EZH2, CCNB1, CDK1, BIRC5) were significantly upregulated in HCC with high internal cross-validated diagnostic accuracy (AUC > 0.96), although these estimates may be susceptible to overfitting and require external validation. Molecular docking and dynamics simulations predicted stable BPA binding to six proteins (Ki67, Cyclin A2, EZH2, Cyclin B1, CDK1, Survivin), with van der Waals forces calculated as the primary driving energy contribution by MM-PBSA. The two-gene (CCNB1/EZH2) risk model showed statistical associations with patient survival, validated internally and externally, although its generalizability remains limited. Mendelian randomization provided genetic evidence consistent with a potential risk-associated role for CCNB1 and a protective-associated role for EZH2. Single-cell analysis localized high CCNB1 and EZH2 expression to malignant and proliferative T-cells, correlating with specific immune infiltration patterns and checkpoint expression. In conclusion, these computational findings suggest a statistical and structural association between BPA exposure and HCC-related core cell-cycle regulators (e.g., CCNB1/EZH2). The data generate the hypothesis that CCNB1 and EZH2 may serve as prognostic biomarkers and potential contributors to HCC biology, possibly through coordinated effects on cell cycle dysregulation and immune microenvironment remodeling, though direct evidence of in vivo molecular targeting by BPA or causal pathway activation is not established by this study. These findings provide novel insights into BPA's putative role in hepatocarcinogenesis and offer clues for future experimental validation regarding risk assessment and therapeutic strategies.