SMURF1 amplification promotes invasiveness in pancreatic cancer

PLoS One. 2011;6(8):e23924. doi: 10.1371/journal.pone.0023924. Epub 2011 Aug 22.

Abstract

Pancreatic cancer is a deadly disease, and new therapeutic targets are urgently needed. We previously identified DNA amplification at 7q21-q22 in pancreatic cancer cell lines. Now, by high-resolution genomic profiling of human pancreatic cancer cell lines and human tumors (engrafted in immunodeficient mice to enrich the cancer epithelial fraction), we define a 325 Kb minimal amplicon spanning SMURF1, an E3 ubiquitin ligase and known negative regulator of transforming growth factor β (TGFβ) growth inhibitory signaling. SMURF1 amplification was confirmed in primary human pancreatic cancers by fluorescence in situ hybridization (FISH), where 4 of 95 cases (4.2%) exhibited amplification. By RNA interference (RNAi), knockdown of SMURF1 in a human pancreatic cancer line with focal amplification (AsPC-1) did not alter cell growth, but led to reduced cell invasion and anchorage-independent growth. Interestingly, this effect was not mediated through altered TGFβ signaling, assayed by transcriptional reporter. Finally, overexpression of SMURF1 (but not a catalytic mutant) led to loss of contact inhibition in NIH-3T3 mouse embryo fibroblast cells. Together, these findings identify SMURF1 as an amplified oncogene driving multiple tumorigenic phenotypes in pancreatic cancer, and provide a new druggable target for molecularly directed therapy.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Communication
  • Cell Line
  • Cell Line, Tumor
  • Gene Amplification / physiology*
  • Humans
  • In Situ Hybridization, Fluorescence
  • Mice
  • Neoplasm Invasiveness
  • Oncogenes
  • Pancreatic Neoplasms / genetics*
  • Pancreatic Neoplasms / pathology*
  • Ubiquitin-Protein Ligases / genetics*

Substances

  • SMURF1 protein, human
  • Ubiquitin-Protein Ligases