title: Tumour initiating cells and IGF/FGF signalling contribute to sorafenib resistance in hepatocellular carcinoma.
abstract: Sorafenib is effective in hepatocellular carcinoma (HCC), but patients ultimately present disease progression. Molecular mechanisms underlying acquired resistance are still unknown. Herein, we characterise the role of tumour-initiating cells (T-ICs) and signalling pathways involved in sorafenib resistance.
  
  
  
  HCC xenograft mice treated with sorafenib (n=22) were explored for responsiveness (n=5) and acquired resistance (n=17). Mechanism of acquired resistance were assessed by: (1) role of T-ICs by in vitro sphere formation and in vivo tumourigenesis assays using NOD/SCID mice, (2) activation of alternative signalling pathways and (3) efficacy of anti-FGF and anti-IGF drugs in experimental models. Gene expression (microarray, quantitative real-time PCR (qRT-PCR)) and protein analyses (immunohistochemistry, western blot) were conducted. A novel gene signature of sorafenib resistance was generated and tested in two independent cohorts.
  
  
  
  Sorafenib-acquired resistant tumours showed significant enrichment of T-ICs (164 cells needed to create a tumour) versus sorafenib-sensitive tumours (13 400 cells) and non-treated tumours (1292 cells), p<0.001. Tumours with sorafenib-acquired resistance were enriched with insulin-like growth factor (IGF) and fibroblast growth factor (FGF) signalling cascades (false discovery rate (FDR)<0.05). In vitro, cells derived from sorafenib-acquired resistant tumours and two sorafenib-resistant HCC cell lines were responsive to IGF or FGF inhibition. In vivo, FGF blockade delayed tumour growth and improved survival in sorafenib-resistant tumours. A sorafenib-resistance 175 gene signature was characterised by enrichment of progenitor cell features, aggressive tumorous traits and predicted poor survival in two cohorts (n=442 patients with HCC).
  
  
  
  Acquired resistance to sorafenib is driven by T-ICs with enrichment of progenitor markers and activation of IGF and FGF signalling. Inhibition of these pathways would benefit a subset of patients after sorafenib progression.
authors.affiliation: Liver Cancer Translational Research Laboratory, Barcelona Clinic Liver Cancer (BCLC) Group, Liver Unit and Pathology Department, IDIBAPS, Hospital Clínic, CIBERehd, Universitat de Barcelona, Barcelona, Spain.
authors.forename: Victoria
authors.initials: V
authors.lastname: Tovar
authors.affiliation: Liver Cancer Translational Research Laboratory, Barcelona Clinic Liver Cancer (BCLC) Group, Liver Unit and Pathology Department, IDIBAPS, Hospital Clínic, CIBERehd, Universitat de Barcelona, Barcelona, Spain.
authors.forename: Helena
authors.initials: H
authors.lastname: Cornella
authors.affiliation: Liver Cancer Translational Research Laboratory, Barcelona Clinic Liver Cancer (BCLC) Group, Liver Unit and Pathology Department, IDIBAPS, Hospital Clínic, CIBERehd, Universitat de Barcelona, Barcelona, Spain.
authors.forename: Agrin
authors.initials: A
authors.lastname: Moeini
authors.affiliation: Department of Pathology, Icahn School of Medicine at Mount Sinai, New York, USA.
authors.forename: Samuel
authors.initials: S
authors.lastname: Vidal
authors.affiliation: Liver Cancer Program, Division of Liver Diseases, Department of Medicine, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, USA.
authors.forename: Yujin
authors.initials: Y
authors.lastname: Hoshida
authors.affiliation: Liver Cancer Translational Research Laboratory, Barcelona Clinic Liver Cancer (BCLC) Group, Liver Unit and Pathology Department, IDIBAPS, Hospital Clínic, CIBERehd, Universitat de Barcelona, Barcelona, Spain.|Liver Cancer Program, Division of Liver Diseases, Department of Medicine, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, USA.|Gastrointestinal Surgery and Liver Transplantation Unit, National Cancer Institute, Milan, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Sia
authors.affiliation: Liver Cancer Translational Research Laboratory, Barcelona Clinic Liver Cancer (BCLC) Group, Liver Unit and Pathology Department, IDIBAPS, Hospital Clínic, CIBERehd, Universitat de Barcelona, Barcelona, Spain.
authors.forename: Judit
authors.initials: J
authors.lastname: Peix
authors.affiliation: Liver Cancer Translational Research Laboratory, Barcelona Clinic Liver Cancer (BCLC) Group, Liver Unit and Pathology Department, IDIBAPS, Hospital Clínic, CIBERehd, Universitat de Barcelona, Barcelona, Spain.
authors.forename: Laia
authors.initials: L
authors.lastname: Cabellos
authors.affiliation: Liver Cancer Translational Research Laboratory, Barcelona Clinic Liver Cancer (BCLC) Group, Liver Unit and Pathology Department, IDIBAPS, Hospital Clínic, CIBERehd, Universitat de Barcelona, Barcelona, Spain.
authors.forename: Clara
authors.initials: C
authors.lastname: Alsinet
authors.affiliation: Liver Cancer Translational Research Laboratory, Barcelona Clinic Liver Cancer (BCLC) Group, Liver Unit and Pathology Department, IDIBAPS, Hospital Clínic, CIBERehd, Universitat de Barcelona, Barcelona, Spain.
authors.forename: Sara
authors.initials: S
authors.lastname: Torrecilla
authors.affiliation: Liver Cancer Translational Research Laboratory, Barcelona Clinic Liver Cancer (BCLC) Group, Liver Unit and Pathology Department, IDIBAPS, Hospital Clínic, CIBERehd, Universitat de Barcelona, Barcelona, Spain.
authors.forename: Iris
authors.initials: I
authors.lastname: Martinez-Quetglas
authors.affiliation: Bioinformatic Platform, IDIBAPS, CIBERehd, Barcelona, Spain.
authors.forename: Juan José
authors.initials: JJ
authors.lastname: Lozano
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, UMR_S 938, Saint-Antoine Research Center, Paris, France.|INSERM UMR_S 938, Saint-Antoine Research Center, Paris, France.
authors.forename: Christèle
authors.initials: C
authors.lastname: Desbois-Mouthon
authors.affiliation: Liver Cancer Translational Research Laboratory, Barcelona Clinic Liver Cancer (BCLC) Group, Liver Unit and Pathology Department, IDIBAPS, Hospital Clínic, CIBERehd, Universitat de Barcelona, Barcelona, Spain.
authors.forename: Manel
authors.initials: M
authors.lastname: Solé
authors.affiliation: Department of Pathology, Icahn School of Medicine at Mount Sinai, New York, USA.
authors.forename: Josep
authors.initials: J
authors.lastname: Domingo-Domenech
authors.affiliation: Liver Cancer Program, Division of Liver Diseases, Department of Medicine, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, USA.|Division of Hematology and Medical Oncology, Icahn School of Medicine at Mount Sinai, New York, USA.
authors.forename: Augusto
authors.initials: A
authors.lastname: Villanueva
authors.affiliation: Liver Cancer Translational Research Laboratory, Barcelona Clinic Liver Cancer (BCLC) Group, Liver Unit and Pathology Department, IDIBAPS, Hospital Clínic, CIBERehd, Universitat de Barcelona, Barcelona, Spain.|Liver Cancer Program, Division of Liver Diseases, Department of Medicine, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, USA.|Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain.
authors.forename: Josep M
authors.initials: JM
authors.lastname: Llovet
mesh_terms: D000368:Aged; D000818:Animals; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D045744:Cell Line, Tumor; D018450:Disease Progression; D019008:Drug Resistance, Neoplasm; D005260:Female; D005346:Fibroblast Growth Factors / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D020869:Gene Expression Profiling; D006801:Humans; D008113:Liver Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009536:Niacinamide / Q000031:analogs & derivatives* / Q000627:therapeutic use; D010671:Phenylurea Compounds / Q000627:therapeutic use*; D051496:Receptor, Fibroblast Growth Factor, Type 1 / Q000037:antagonists & inhibitors / Q000378:metabolism; D017526:Receptor, IGF Type 1; D017451:Receptors, Somatomedin / Q000037:antagonists & inhibitors / Q000378:metabolism; D015398:Signal Transduction; D013002:Somatomedins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D000077157:Sorafenib; D018874:Spheroids, Cellular; D015996:Survival Rate; D023041:Xenograft Model Antitumor Assays
chemical_list: D000970:Antineoplastic Agents; C000597236:IGF1R protein, human; D010671:Phenylurea Compounds; D017451:Receptors, Somatomedin; D013002:Somatomedins; D009536:Niacinamide; D005346:Fibroblast Growth Factors; D000077157:Sorafenib; C496348:FGFR1 protein, human; D051496:Receptor, Fibroblast Growth Factor, Type 1; D017526:Receptor, IGF Type 1
keywords: DRUG RESISTANCE; HEPATOCELLULAR CARCINOMA; MOLECULAR GENETICS; MOLECULAR MECHANISMS; STEM CELLS