Uterine leiomyoma presents the highest incidence among benign tumors of the female reproductive tract. The present study compared the proteome of leiomyoma treated with ulipristal acetate with that of untreated leiomyoma to investigate protein expression patterns in relation to oxidative stress. Paired tissue samples from seven treated and untreated leiomyomas were collected and the proteome was analyzed by two‐dimensional gel electrophoresis (2‐DE). Western blotting was used to validate the results of 2‐DE, and mass spectrom‐ etry was used to identify proteins. The tissue expression of 30 proteins was markedly affected by treatment with ulipristal acetate. Bioinformatics analysis revealed that several of the differentially expressed proteins were involved in the degrada‐ tion of hydrogen peroxide and the synthesis of reactive oxygen species. The present study suggested the involvement of oxida‐ tive stress as a novel mechanism of action of ulipristal acetate. These findings require further investigations to understand the role of ulipristal acetate in the treatment of the leiomyoma.
