Downregulation of signal transducer and activator of transcription 3 by sorafenib: a novel mechanism for hepatocellular carcinoma therapy.
Hepatocellular carcinoma is one of the most common cancers worldwide, and a leading cause of cancer-related death. Owing to unsatisfactory clinical outcomes under the current standard of care, there is a need to search for and identify novel and potent therapeutic targets to improve patient outcomes. Sorafenib is the first and only approved targeted therapy for the treatment of hepatocellular carcinoma. Besides functioning as a multiple tyrosine kinase, sorafenib also acts via a kinase-independent mechanism to target signal transducer and activator of transcription 3 (STAT3) signaling in hepatocellular carcinoma cells. STAT3 is a key regulator of inflammation, cell survival, and tumorigenesis of liver cells, and the high percentage of hepatocellular carcinoma cells with constitutively active STAT3 justifies targeting it for the development of novel therapeutics. Sorafenib inactivates STAT3 and STAT3-related signaling by inducing a conformational change in and releasing the autoinhibition of Src homology region 2 domain-containing phosphatase-1. This phosphatase negatively regulates STAT3 activity, which leads to the subsequent apoptosis of cancer cells. The novel anti-cancer property of sorafenib will be discussed in this review, not only adding information regarding its mechanism of action but also providing an innovative approach for the development of cancer therapeutics in the future.
Man-Hsin Hung, Division of Hematology and Oncology, Department of Medicine, Taipei Veterans General Hospital, Taipei 112, Taiwan.
Man-Hsin
MH
Hung
Man-Hsin Hung, Division of Hematology and Oncology, Department of Medicine, Taipei Veterans General Hospital, Taipei 112, Taiwan.
Wei-Tien
WT
Tai
Man-Hsin Hung, Division of Hematology and Oncology, Department of Medicine, Taipei Veterans General Hospital, Taipei 112, Taiwan.
Chung-Wai
CW
Shiau
Man-Hsin Hung, Division of Hematology and Oncology, Department of Medicine, Taipei Veterans General Hospital, Taipei 112, Taiwan.
Kuen-Feng
KF
Chen
D000818:Animals; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D017209:Apoptosis / Q000187:drug effects; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D015536:Down-Regulation; D006801:Humans; D008113:Liver Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D058990:Molecular Targeted Therapy; D009536:Niacinamide / Q000031:analogs & derivatives* / Q000627:therapeutic use; D010671:Phenylurea Compounds / Q000627:therapeutic use*; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use*; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6 / Q000378:metabolism; D050796:STAT3 Transcription Factor / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D000077157:Sorafenib; D016896:Treatment Outcome
D000970:Antineoplastic Agents; D010671:Phenylurea Compounds; D047428:Protein Kinase Inhibitors; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; D009536:Niacinamide; D000077157:Sorafenib; C509249:PTPN6 protein, human; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6
Hepatocellular carcinoma; Kinase-independent; Signal transducer and activator of transcription 3; Sorafenib; Target therapy