title: Inhibition of hedgehog signaling attenuates carcinogenesis in vitro and increases necrosis of cholangiocellular carcinoma.
abstract: The Hedgehog signaling pathway plays a pivotal role during embryonic development, stem cell maintenance, and wound healing. Hedgehog signaling also is deregulated in many cancers. However, the role of this signaling pathway in the carcinogenesis of cholangiocarcinoma (CCC) is still unknown. In this study, we investigated the effects of Hedgehog inhibition by cyclopamine and 5E1 in cultured human CCC cell lines and in vivo using a xenograft mouse model. We also investigated the involvement of Hedgehog in epithelial to mesenchymal transition (EMT), migration, and CCC tumor growth. Sonic hedgehog (Shh) ligand was highly expressed in 89% of human CCC tissues and in CCC cell lines. Cyclopamine and 5E1 treatments effectively inhibited cell proliferation, migration, and invasion by down-regulating the Hedgehog target genes glioblastoma 1 and glioblastoma 2. In vitro and in vivo, we detected an increase in epithelial marker, E-cadherin, after Hedgehog inhibition. In addition, we saw an increase in necrotic areas and a decrease in mitotic figures in cyclopamine and 5E1-treated CCC xenograft tumors.
  
  
  CONCLUSIONS
  This study supports the presence of autocrine Hedgehog signaling in human CCC, where CCC cells produce and respond to Shh ligand. Blocking the Hedgehog pathway inhibited EMT and decreased the viability of CCC cells. In addition, cyclopamine and 5E1 inhibited the growth of CCC xenograft tumors.
authors.affiliation: Department of Internal Medicine I, Medical University Hospital, Tuebingen, Germany.
authors.forename: Mona
authors.initials: M
authors.lastname: El Khatib
authors.forename: Anna
authors.initials: A
authors.lastname: Kalnytska
authors.forename: Vindhya
authors.initials: V
authors.lastname: Palagani
authors.forename: Uta
authors.initials: U
authors.lastname: Kossatz
authors.forename: Michael P
authors.initials: MP
authors.lastname: Manns
authors.forename: Nisar P
authors.initials: NP
authors.lastname: Malek
authors.forename: Ludwig
authors.initials: L
authors.lastname: Wilkens
authors.forename: Ruben R
authors.initials: RR
authors.lastname: Plentz
mesh_terms: D000818:Animals; D019898:Autocrine Communication / Q000187:drug effects / Q000502:physiology; D001650:Bile Duct Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D001653:Bile Ducts, Intrahepatic / Q000473:pathology*; D015820:Cadherins / Q000378:metabolism; D045744:Cell Line, Tumor; D018281:Cholangiocarcinoma / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D005260:Female; D053823:Hedgehog Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D051379:Mice; D008819:Mice, Nude; D009336:Necrosis; D009368:Neoplasm Transplantation; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D014704:Veratrum Alkaloids / Q000494:pharmacology*; D023041:Xenograft Model Antitumor Assays
chemical_list: D015820:Cadherins; D053823:Hedgehog Proteins; C509239:SHH protein, human; D014704:Veratrum Alkaloids; C000541:cyclopamine