Activated KrasG¹²D is associated with invasion and metastasis of pancreatic cancer cells through inhibition of E-cadherin

Br J Cancer. 2011 Mar 15;104(6):1038-48. doi: 10.1038/bjc.2011.31. Epub 2011 Mar 1.

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.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adenocarcinoma / genetics*
  • Adenocarcinoma / pathology*
  • Amino Acid Substitution / genetics
  • Amino Acid Substitution / physiology
  • Animals
  • Aspartic Acid / genetics
  • Cadherins / genetics*
  • Cadherins / physiology
  • Down-Regulation / drug effects
  • Gene Expression Regulation, Neoplastic / drug effects
  • Glycine / genetics
  • Humans
  • Mice
  • Mice, Nude
  • Neoplasm Invasiveness
  • Neoplasm Metastasis
  • Pancreatic Neoplasms / genetics*
  • Pancreatic Neoplasms / pathology*
  • Point Mutation
  • Proto-Oncogene Proteins / genetics*
  • Proto-Oncogene Proteins / metabolism
  • Proto-Oncogene Proteins p21(ras)
  • RNA, Small Interfering / pharmacology
  • Tumor Cells, Cultured
  • Xenograft Model Antitumor Assays
  • ras Proteins / genetics*
  • ras Proteins / metabolism

Substances

  • Cadherins
  • KRAS protein, human
  • Proto-Oncogene Proteins
  • RNA, Small Interfering
  • Aspartic Acid
  • Proto-Oncogene Proteins p21(ras)
  • ras Proteins
  • Glycine