title: Growth of human pancreatic cancer is inhibited by down-regulation of gastrin gene expression.
abstract: OBJECTIVE
  This study evaluated the effects of gastrin messenger RNA (mRNA) down-regulation on growth of human pancreatic cancer.
  
  
  METHODS
  Gastrin expression was examined in human pancreatic cancer cell lines by reverse transcriptase-polymerase chain reaction, and peptide expression was assessed by immunocytochemistry. Gastrin was down-regulated using either stable transfection of an antisense gastrin cDNA or 1 of 3 shRNA (short hairpin RNA) constructs. Tumor formation was evaluated after either subcutaneous or orthotopic injections into nude mice. The effect of nanoliposomes loaded with gastrin siRNA (small interfering RNA) was tested in mice bearing pancreatic tumors.
  
  
  RESULTS
  Stable transfection of gastrin antisense or shRNAs into BxPC-3 cells resulted in clones with more than 90% reduction in gastrin mRNA. Tumor growth rate and incidence of metastases in both wild-type and transfected pancreatic cancer cells were directly proportional to the degrees of gastrin mRNA expression. Immunofluorescence analysis confirmed that gastrin peptide levels were decreased in antisense and shRNA tumors. Gastrin knockdown clones had lower Ki-67 and increased cleaved caspase-3 staining, consistent with known effects of gastrin on proliferation and apoptosis. Tumors in mice treated with gastrin siRNA were smaller than controls.
  
  
  CONCLUSIONS
  These results suggest that RNAi targeting of gastrin could serve as an effective treatment for pancreatic cancer.
authors.affiliation: Department of Biochemistry and Molecular Biology, Pennsylvania State University College of Medicine, Hershey, PA 17011, USA.
authors.forename: Gail L
authors.initials: GL
authors.lastname: Matters
authors.forename: John F
authors.initials: JF
authors.lastname: Harms
authors.forename: Christopher O
authors.initials: CO
authors.lastname: McGovern
authors.forename: Calpurnia
authors.initials: C
authors.lastname: Jayakumar
authors.forename: Keisha
authors.initials: K
authors.lastname: Crepin
authors.forename: Zachary P
authors.initials: ZP
authors.lastname: Smith
authors.forename: Melissa C
authors.initials: MC
authors.lastname: Nelson
authors.forename: Heather
authors.initials: H
authors.lastname: Stock
authors.forename: Craig W
authors.initials: CW
authors.lastname: Fenn
authors.forename: James
authors.initials: J
authors.lastname: Kaiser
authors.forename: Mark
authors.initials: M
authors.lastname: Kester
authors.forename: Jill P
authors.initials: JP
authors.lastname: Smith
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002851:Chromatography, High Pressure Liquid; D005455:Fluorescent Antibody Technique; D005755:Gastrins / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D019394:Ki-67 Antigen / Q000032:analysis; D008081:Liposomes; D013058:Mass Spectrometry; D051379:Mice; D008819:Mice, Nude; D036103:Nanotechnology; D010190:Pancreatic Neoplasms / Q000235:genetics / Q000473:pathology* / Q000628:therapy; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection; D047368:Tumor Burden; D023041:Xenograft Model Antitumor Assays
chemical_list: D005755:Gastrins; D019394:Ki-67 Antigen; D008081:Liposomes; D012333:RNA, Messenger; D034741:RNA, Small Interfering