Integrated reverse network toxicology and experimental validation identify PTP4A3 as a key target of Benzo[a]pyrene...

Prostate cancer (PCa), a leading cause of cancer morbidity in males globally, is closely related to genetic susceptibility and environmental exposure, which is difficult to clarify by traditional methods. To elucidate this mechanism, we adopted an integrated strategy that combined multi-omics profiling. By integrating multiple transcriptomics datasets, performing weighted gene co-expression network analysis, and applying 113 machine-learning diagnostic models, the 20 hub genes were identified. Two-sample MR further provided genetic evidence that elevated PTP4A3 expression is associated with increased PCa risk (IVW OR = 1.124, p = 0.0389); western blotting analysis also confirmed upregulated PTP4A3 protein level in PCa cell lines (DU145, PC-3), validating the genetic and transcriptomic findings at the protein level. Subsequently, reverse network toxicology and molecular docking prioritized benzo[a]pyrene (BaP) as a high predicted-affinity candidate ligand for PTP4A3 (binding energy = -9.1 kcal/mol), with 100 ns molecular dynamics simulations further predicting stable complex formation (ΔGbind = -13.16 kcal/mol). In RWPE-1 cells, BaP treatment dose- and time-dependently elevated PTP4A3 expression, enhanced cell migration and invasion, and increased wound closure, suggesting that BaP might contribute to the acquisition of invasion-associated phenotypes in non-tumorigenic prostate epithelial cells; all these phenotypes were partially reversed upon PTP4A3 knockdown. In addition, PTP4A3 overexpression significantly upregulated FN1, ITGA3, and MMP9 in RWPE-1 cells, validating the ECM-receptor interaction and focal adhesion pathways identified by gene set enrichment analysis (GSEA). These findings suggested that BaP could contribute to the acquisition of pro-invasive phenotypes in prostate epithelial cells and potentially to prostate carcinogenesis, probably through upregulating PTP4A3 to activate matrix remodeling programs.