title: Simultaneous gene silencing of Bcl-2, XIAP and Survivin re-sensitizes pancreatic cancer cells towards apoptosis.
abstract: BACKGROUND
  Pancreatic ductal adenocarcinoma shows a distinct apoptosis resistance, which contributes significantly to the aggressive nature of this tumor and constrains the effectiveness of new therapeutic strategies. Apoptosis resistance is determined by the net balance of the cells pro-and anti-apoptotic "control mechanisms". Numerous dysregulated anti-apoptotic genes have been identified in pancreatic cancer and seem to contribute to the high anti-apoptotic buffering capacity. We aimed to compare the benefit of simultaneous gene silencing (SGS) of several candidate genes with conventional gene silencing of single genes.
  
  
  METHODS
  From literature search we identified the anti-apoptotic genes XIAP, Survivin and Bcl-2 as commonly upregulated in pancreatic cancer. We performed SGS and silencing of single candidate genes using siRNA molecules in two pancreatic cancer cell lines. Effectiveness of SGS was assessed by qRT-PCR and western blotting. Apoptosis induction was measured by flow cytometry and caspase activation.
  
  
  RESULTS
  Simultaneous gene silencing reduced expression of the three target genes effectively. Compared to silencing of a single target or control, SGS of these genes resulted in a significant higher induction of apoptosis in pancreatic cancer cells.
  
  
  CONCLUSIONS
  In the present study we performed a subliminal silencing of different anti-apoptotic target genes simultaneously. Compared to silencing of single target genes, SGS had a significant higher impact on apoptosis induction in pancreatic cancer cells. Thereby, we give further evidence for the concept of an anti-apoptotic buffering capacity of pancreatic cancer cells.
authors.affiliation: Department of Visceral, Thoracic and Vascular Surgery, University Hospital Carl Gustav Carus, Technische Universität Dresden, Fetscherstrasse 47, 01307 Dresden, Germany. Felix.Rueckert@uniklinikum-dresden.de
authors.forename: Felix
authors.initials: F
authors.lastname: Rückert
authors.forename: Nicole
authors.initials: N
authors.lastname: Samm
authors.forename: Anne-Kathrin
authors.initials: AK
authors.lastname: Lehner
authors.forename: Hans-Detlev
authors.initials: HD
authors.lastname: Saeger
authors.forename: Robert
authors.initials: R
authors.lastname: Grützmann
authors.forename: Christian
authors.initials: C
authors.lastname: Pilarsky
mesh_terms: D017209:Apoptosis; D015153:Blotting, Western; D021441:Carcinoma, Pancreatic Ductal / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D020169:Caspases / Q000378:metabolism; D004789:Enzyme Activation; D005434:Flow Cytometry; D020868:Gene Silencing; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins; D008869:Microtubule-Associated Proteins / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D010190:Pancreatic Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D034741:RNA, Small Interfering / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000077022:Survivin; D014407:Tumor Cells, Cultured; D051636:X-Linked Inhibitor of Apoptosis Protein / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism
chemical_list: C107489:BIRC5 protein, human; D051034:Inhibitor of Apoptosis Proteins; D008869:Microtubule-Associated Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D000077022:Survivin; D051636:X-Linked Inhibitor of Apoptosis Protein; C496866:XIAP protein, human; D020169:Caspases