title: Cyclopamine reverts acquired chemoresistance and down-regulates cancer stem cell markers in pancreatic cancer cell lines.
abstract: BACKGROUND
  The hedgehog (Hh) pathway has been implicated in the pathogenesis of cancer including pancreatic ductal adenocarcinoma (PDAC). Recent studies have suggested that Hh plays an important role in maintaining the cancer stem cell (CSCs) pool. Gemcitabine-resistant pancreatic cancer cells highly express some of the CSCs markers. However, the expression level of Hh members in gemcitabine-resistant pancreatic cancer cells remains unknown. The aim of this study was to verify the expression of HH members, such as Shh, Ptc, SMO and Gli-1 in gemcitabine-resistant PDAC cell lines, and to explore a new strategy to overcome chemoresistance in PDAC.
  
  
  METHODS
  Quantitative real-time RT-PCR (Q-PCR) and western blot were used to evaluate the relative expression level of HH members in SW1990, CFPAC-1 cells and gemcitabine-resistant SW1990, CFPAC-1 cells. The change of cancer stem cell markers and the expression level of HH members before and after cyclopamine treatment was evaluated using flow cytometry and Q-PCR, western blot, respectively. Cell apoptosis after cyclopamine treatment was measured by flow cytometry.
  
  
  RESULTS
  CD44, CD133 and the expression level of HH members, including Shh, SMO, Gli-1, were found to be highly expressed in gemcitabine-resistant cells, which were significantly down-regulated by cyclopamine treatment. Flow cytometry analysis showed increased cell apoptosis after cyclopamine treatment.
  
  
  CONCLUSIONS
  Gemcitabine-resistant pancreatic cancer cells highly express CSCs markers and some of the HH members, and inhibition of HH by cyclopamine is an effective method of reversing gemcitabine resistance in pancreatic cancer.
authors.affiliation: Department of General Surgery, The First Affiliated Hospital of Yangzhou University, Yangzhou, P R China.
authors.forename: Jie
authors.initials: J
authors.lastname: Yao
authors.forename: Yong
authors.initials: Y
authors.lastname: An
authors.forename: Ji-shu
authors.initials: JS
authors.lastname: Wie
authors.forename: Zhen-ling
authors.initials: ZL
authors.lastname: Ji
authors.forename: Zi-peng
authors.initials: ZP
authors.lastname: Lu
authors.forename: Jun-li
authors.initials: JL
authors.lastname: Wu
authors.forename: Kui-rong
authors.initials: KR
authors.lastname: Jiang
authors.forename: Ping
authors.initials: P
authors.lastname: Chen
authors.forename: Ze-kuan
authors.initials: ZK
authors.lastname: Xu
authors.forename: Yi
authors.initials: Y
authors.lastname: Miao
mesh_terms: D000071916:AC133 Antigen; D000070998:ATP Binding Cassette Transporter, Subfamily G, Member 1; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism; D015703:Antigens, CD / Q000378:metabolism; D017209:Apoptosis; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism*; D021441:Carcinoma, Pancreatic Ductal / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism*; D003841:Deoxycytidine / Q000031:analogs & derivatives / Q000627:therapeutic use; D015536:Down-Regulation; D019008:Drug Resistance, Neoplasm / Q000187:drug effects*; D006023:Glycoproteins / Q000378:metabolism; D053823:Hedgehog Proteins / Q000378:metabolism; D006801:Humans; D018960:Hyaluronan Receptors / Q000378:metabolism; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism; D014411:Neoplastic Stem Cells / Q000187:drug effects* / Q000378:metabolism*; D015513:Oncogene Proteins / Q000235:genetics / Q000378:metabolism; D010190:Pancreatic Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism*; D000072079:Patched Receptors; D010455:Peptides / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000378:metabolism; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism; D015398:Signal Transduction; D000072086:Smoothened Receptor; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism; D014407:Tumor Cells, Cultured; D014704:Veratrum Alkaloids / Q000494:pharmacology*; D000071676:Zinc Finger Protein GLI1; D000093542:Gemcitabine
chemical_list: C419353:ABCG1 protein, human; C116614:ABCG2 protein, human; D000071916:AC133 Antigen; D000070998:ATP Binding Cassette Transporter, Subfamily G, Member 1; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters; D015703:Antigens, CD; D014408:Biomarkers, Tumor; C497483:CD44 protein, human; D006023:Glycoproteins; D053823:Hedgehog Proteins; D018960:Hyaluronan Receptors; D009363:Neoplasm Proteins; D015513:Oncogene Proteins; C000606023:PROM1 protein, human; D000072079:Patched Receptors; D010455:Peptides; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled; C509239:SHH protein, human; C491023:SMO protein, human; D000072086:Smoothened Receptor; D015534:Trans-Activators; D014704:Veratrum Alkaloids; D000071676:Zinc Finger Protein GLI1; D003841:Deoxycytidine; C000541:cyclopamine; D000093542:Gemcitabine