title: Signal transducer and activator of transcription 3 as molecular therapy for non-small-cell lung cancer.
abstract: BACKGROUND
  Targeting signal transducer and activator of transcription 3 (STAT3), a transcription factor that modulates survival-directed transcription, is often persistently activated in epidermal growth factor receptor (EGFR) wild-type non-small-cell lung cancer (NSCLC). The aim of this study was to determine whether sorafenib and its derivative can inhibit EGFR wild-type NSCLC via STAT3 inactivation.
  
  
  METHODS
  EGFR wild-type NSCLC cell lines (A549 H292 H322 H358 and H460) were treated with sorafenib or SC-1, a sorafenib derivative that closely resembled sorafenib structurally but was devoid of kinase inhibitory activity. Apoptosis and signal transduction were analyzed. In vivo efficacy was determined in nude mice with H460 and A549 xenograft.
  
  
  RESULTS
  SC-1 had better effects than sorafenib on growth inhibition and apoptosis in all tested EGFR wild-type NSCLC lines. SC-1 reduced STAT3 phosphorylation at tyrosine 705 in all tested EGFR wild-type NSCLC cells. The expression of STAT3-driven genes, including cylcin D1 and survivin, was also repressed by SC-1. Ectopic expression of STAT3 in H460 cells abolished apoptosis in SC-1-treated cells. Sorafenib and SC-1 enhanced Src homology-2 containing protein tyrosine phosphatase-1 (SHP-1) activity, whereas knockdown of SHP-1, but not SHP-2 or protein-tyrosine phosphatase 1B (PTP-1B), by small interference RNA reduced SC-1-induced apoptosis. SC-1 significantly reduced H460 and A549 tumor growth in vivo through SHP-1/STAT3 pathway.
  
  
  CONCLUSIONS
  SC-1 provides proof that targeting STAT3 signaling pathway may be a novel approach for the treatment of EGFR wild-type NSCLC.
authors.affiliation: *Medical Research Center, †Department of Internal Medicine, Cardinal Tien Hospital, Fu Jen Catholic University, New Taipei City, Taiwan; ‡Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan; §Department of Medical Research, National Taiwan University Hospital and National Taiwan University, Taipei, Taiwan; ‖National Center of Excellence for Clinical Trial and Research, National Taiwan University Hospital and National Taiwan University, Taipei, Taiwan; ¶Department of Internal Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan; #Department of Pathology, Cardinal Tien Hospital, Fu Jen Catholic University, New Taipei City, Taiwan; **Department of Emergency Medicine, National Taiwan University Hospital and National Taiwan University, Taipei, Taiwan; ††Institute of Biopharmaceutical Sciences, National Yang-Ming University, Taipei, Taiwan; and ‡‡Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University, Taipei, Taiwan.
authors.forename: Cheng-Yi
authors.initials: CY
authors.lastname: Wang
authors.forename: Ting-Ting
authors.initials: TT
authors.lastname: Chao
authors.forename: Wei-Tien
authors.initials: WT
authors.lastname: Tai
authors.forename: Fang-Yu
authors.initials: FY
authors.lastname: Chang
authors.forename: Wen-Pin
authors.initials: WP
authors.lastname: Su
authors.forename: Yen-Lin
authors.initials: YL
authors.lastname: Chen
authors.forename: Pao-Tzu
authors.initials: PT
authors.lastname: Chen
authors.forename: Ching-Yu
authors.initials: CY
authors.lastname: Weng
authors.forename: Ang
authors.initials: A
authors.lastname: Yuan
authors.forename: Chung-Wai
authors.initials: CW
authors.lastname: Shiau
authors.forename: Chong-Jen
authors.initials: CJ
authors.lastname: Yu
authors.forename: Kuen-Feng
authors.initials: KF
authors.lastname: Chen
mesh_terms: D002282:Adenocarcinoma, Bronchiolo-Alveolar / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D018287:Carcinoma, Large Cell / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D002470:Cell Survival / Q000187:drug effects; D006801:Humans; D007124:Immunoenzyme Techniques; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D008297:Male; D051379:Mice; D008819:Mice, Nude; D058990:Molecular Targeted Therapy; D009536:Niacinamide / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D010671:Phenylurea Compounds / Q000737:chemistry / Q000494:pharmacology*; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D019908:Proto-Oncogene Proteins c-raf / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics; D050796:STAT3 Transcription Factor / Q000037:antagonists & inhibitors*; D000077157:Sorafenib; D014407:Tumor Cells, Cultured; D023041:Xenograft Model Antitumor Assays
chemical_list: D000970:Antineoplastic Agents; D010671:Phenylurea Compounds; D034741:RNA, Small Interfering; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; D009536:Niacinamide; D000077157:Sorafenib; D019908:Proto-Oncogene Proteins c-raf; C509249:PTPN6 protein, human; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6