Valproic acid synergistically enhances the cytotoxicity of gossypol in DU145 prostate cancer cells: An iTRTAQ-based quantitative proteomic analysis

► Valproic acid synergistically enhanced the cytotoxicity of gossypol on prostate cancer DU145 cells. ► iTRAQ-based quantitative proteomic analysis revealed differential proteomic profiles in valproic acid plus gossypol-treated cells. ► Valproic acid plus gossypol enhanced mitochondrial stress and decreased DNA damage repair ability of cells. ► Downregulation of DNA damage repair proteins might promote DNA fragmentation and cell death.