title: Activated KrasG¹²D is associated with invasion and metastasis of pancreatic cancer cells through inhibition of E-cadherin.
abstract: BACKGROUND
  Pancreatic cancer (PC) harbours an activated point mutation (Kras(G12D)) in the Kras proto-oncogene that has been demonstrated to promote the development of PC.
  
  
  METHODS
  This study was designed to investigate the effect of the oncogenic Kras(G12D) allele on aggressiveness and metastatic potential of PC cells. We silenced the oncogenic Kras(G12D) allele expression in CD18/HPAF and ASPC1 cell lines by stable expression of shRNA specific to the Kras(G12D)allele.
  
  
  RESULTS
  The Kras(G12D) knockdown cells exhibited a significant decrease in motility (P<0.0001), invasion (P<0.0001), anchorage-dependent (P<0.0001) and anchorage-independent growth (P<0.0001), proliferation (P<0.005) and an increase in cell doubling time (P<0.005) in vitro and a decrease in the incidence of metastases upon orthotopic implantation into nude mice. The knockdown of the Kras(G12D) allele led to a significant increase in the expression of E-cadherin (mRNA and protein) both in vitro and in vivo. This was associated with a decrease in the expression of phoshpo-ERK-1/2, NF-κB and MMP-9, and transcription factors such as δEF1, Snail and ETV4. Furthermore, the expression of several proteins involved in cell survival, invasion and metastasis was decreased in the Kras(G12D) knockdown cells.
  
  
  CONCLUSIONS
  The results of this study suggest that the Kras(G12D) allele promotes metastasis in PC cells partly through the downregulation of E-cadherin.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA.
authors.forename: S
authors.initials: S
authors.lastname: Rachagani
authors.forename: S
authors.initials: S
authors.lastname: Senapati
authors.forename: S
authors.initials: S
authors.lastname: Chakraborty
authors.forename: M P
authors.initials: MP
authors.lastname: Ponnusamy
authors.forename: S
authors.initials: S
authors.lastname: Kumar
authors.forename: L M
authors.initials: LM
authors.lastname: Smith
authors.forename: M
authors.initials: M
authors.lastname: Jain
authors.forename: S K
authors.initials: SK
authors.lastname: Batra
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics* / Q000473:pathology*; D019943:Amino Acid Substitution / Q000235:genetics / Q000502:physiology; D000818:Animals; D001224:Aspartic Acid / Q000235:genetics; D015820:Cadherins / Q000235:genetics* / Q000502:physiology; D015536:Down-Regulation / Q000187:drug effects; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D005998:Glycine / Q000235:genetics; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D009361:Neoplasm Invasiveness; D009362:Neoplasm Metastasis; D010190:Pancreatic Neoplasms / Q000235:genetics* / Q000473:pathology*; D017354:Point Mutation; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins / Q000235:genetics* / Q000378:metabolism; D016283:Proto-Oncogene Proteins p21(ras); D034741:RNA, Small Interfering / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D023041:Xenograft Model Antitumor Assays; D018631:ras Proteins / Q000235:genetics* / Q000378:metabolism
chemical_list: D015820:Cadherins; C117307:KRAS protein, human; C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins; D034741:RNA, Small Interfering; D001224:Aspartic Acid; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins; D005998:Glycine