PM2.5 Triggers EMT in Bladder Cancer Cells via Integrin-MAPK/ERK and Wnt Pathways

The Taiwan experiments used human bladder cancer lines exposed to urban PM2.5 extracts. Cells underwent measurable EMT with upregulated vimentin, downregulated E-cadherin, and 2- to 3-fold increases in migration and Matrigel invasion assays. Western blots confirmed sustained ERK phosphorylation and β-catenin nuclear translocation, effects blocked by integrin or pathway inhibitors. Kidney filtration concentrates these particles in urine, creating prolonged urothelial contact absent from lung-centric pollution models. Earlier IARC and large European cohorts linked PM2.5 to bladder cancer incidence but lacked mechanistic data; this study supplies the missing pathway evidence while remaining limited to in-vitro systems. Population-level confirmation requires prospective cohorts measuring personal PM2.5 exposure and urine metabolites against verified bladder cancer progression. Regulatory agencies should integrate non-pulmonary cancer endpoints into future air-quality revisions.