The Association between 2,4-Dichlorophenoxyacetic Acid Exposure and Prostate Cancer Risk: Evidence from Multimodal Studies

The carcinogenic potential of 2,4-Dichlorophenoxyacetic acid (2,4-D) exposure in prostate cancer (PCa) remains poorly understood. This study employed an integrative approach combining epidemiological analysis, network toxicology, and experimental validation to investigate the association and underlying mechanisms. A cross-sectional analysis of 1174 participants was conducted to evaluate the association between urinary 2,4-D concentrations and prostate cancer risk using multivariate logistic regression. Network toxicology predicted overlapping targets between 2,4-D and PCa, followed by functional enrichment, protein–protein interaction analysis, and molecular docking. Hub target expression was validated via immunohistochemistry and single-cell RNA sequencing data. In vitro assays, including colony formation, EdU incorporation, Transwell migration, and Western blot, were performed on PCa cells following 2,4-D exposure. Urinary 2,4-D levels were significantly associated with PCa risk after full covariate adjustment (OR = 1.421; 95% CI: 1.011–1.996; p = 0.043). Network toxicology identified 90 overlapping targets, with enrichment in HIF-1, NF-κB, and reactive oxygen species pathways. PTGS2 emerged as a central hub target, exhibiting overexpression in malignant cells and stable binding affinity with 2,4-D. Functionally, 100 nM 2,4-D exposure significantly enhanced PCa cell proliferation and migration. Mechanistically, 2,4-D upregulated PTGS2 expression at translational levels. Whereas following COX-2i treatment, the aforementioned 2,4-D-induced changes were significantly reversed. This multidimensional investigation provided the additional epidemiological evidence linking environmental 2,4-D exposure to PCa risk, while mechanistically implicating PTGS2 upregulation in 2,4-D-mediated oncogenic phenotypes.