To determine whether di-n-butyl phthalate (DBP) promotes the occurrence of bladder cancer (BCa) and explore the action of DBP acts on BCa cells at the cellular and molecular levels.

MTT and Transwell assays were used to investigate the tumorigenic actions of DBP on BCa cells. Second-generation sequencing was used to identify differences in gene expression before and after DBP treatment. Differential gene expression was verified by q-PCR and analyzed using bioinformatics. Cells were transfected to overexpress genes of interest and proliferation and migration were measured using MTT and Transwell assays, respectively.

DBP treatment stimulated both proliferation and invasion in BCa cells. Second-generation sequencing identified differences in the expression of FOSB, JUND, ATP6V1C2, and RHOQ before and after DBP treatment. FOSB expression was confirmed by q-PCR and bioinformatic analyses. FOSB overexpression increased both proliferation and invasion in BCa cells.

DBP promoted BCa tumorigenesis by inducing changes in gene expression.