TY - JOUR AU - Liese, Juliane AU - Hinrichs, Tobias M AU - Lange, Matthias AU - Fulda, Simone TI - Cotreatment with sorafenib and oleanolic acid induces reactive oxygen species-dependent and mitochondrial-mediated apoptotic cell death in hepatocellular carcinoma cells. JO - Anti-cancer drugs VL - 30 IS - 3 SN - 0959-4973 CY - [S.l.] PB - Ovid M1 - DKFZ-2020-01925 SP - 209 - 217 PY - 2019 AB - Hepatocellular carcinoma (HCC) is the most common liver malignancy, and the lack of effective chemotherapies underlines the need for novel therapeutic approaches for this disease. Recently, we discovered a novel synergistic induction of cell death by combining sorafenib, the only routinely used palliative chemotherapeutic agent, and the triterpenoid oleanolic acid (OA). However, the underlying mechanisms of action have remained obscure. Here, we report that sorafenib and OA acted in concert to trigger mitochondria-mediated apoptotic cell death, which is dependent on reactive oxygen species (ROS). Sorafenib/OA cotreatment significantly increased ROS production, which was prevented by the ROS scavengers α-tocopherol and MnTBAP. Importantly, rescue experiments showed that ROS were required for sorafenib/OA-induced apoptosis as ROS scavengers protected HCC cells against cell death. In addition, sorafenib and OA cotreatment cooperated to decrease myeloid cell leukaemia-1 expression and to activate Bak, two events that were prevented by ROS scavengers. Bak activation was accompanied by the loss of mitochondrial membrane potential, followed by PARP cleavage, DNA fragmentation and, finally, apoptotic cell death in HCC cells. By providing new insights into the molecular regulation of sorafenib/OA-mediated and ROS-dependent cell death, our study contributes toward the development of novel treatment strategies to overcome sorafenib resistance in HCC. KW - Antineoplastic Agents: pharmacology KW - Apoptosis KW - Carcinoma, Hepatocellular: drug therapy KW - Carcinoma, Hepatocellular: metabolism KW - Carcinoma, Hepatocellular: pathology KW - Cell Proliferation KW - Drug Therapy, Combination KW - Humans KW - Liver Neoplasms: drug therapy KW - Liver Neoplasms: metabolism KW - Liver Neoplasms: pathology KW - Membrane Potential, Mitochondrial: drug effects KW - Mitochondria: drug effects KW - Mitochondria: metabolism KW - Mitochondria: pathology KW - Oleanolic Acid: pharmacology KW - Reactive Oxygen Species: metabolism KW - Sorafenib: pharmacology KW - Tumor Cells, Cultured KW - Antineoplastic Agents (NLM Chemicals) KW - Reactive Oxygen Species (NLM Chemicals) KW - Oleanolic Acid (NLM Chemicals) KW - Sorafenib (NLM Chemicals) LB - PUB:(DE-HGF)16 C6 - pmid:30640794 DO - DOI:10.1097/CAD.0000000000000750 UR - https://inrepo02.dkfz.de/record/163644 ER -