RUNX3 inhibits cell proliferation and induces apoptosis by reinstating transforming growth factor beta responsiveness in esophageal adenocarcinoma cells.

Published

Journal Article

BACKGROUND: SEG-1, a Barrett's-derived esophageal adenocarcinoma cell line, is not responsive to transforming growth factor beta (TGF-beta) growth effects. We hypothesize that SEG-1 cells lack the tumor-suppressor gene Runt domain transcription factor 3 (RUNX3) and that its reinstatement can restore the antiproliferative and apoptotic effects of TGF-beta. METHODS: RUNX3 expression was assessed by immunoblotting. SEG-1 cells were transfected with RUNX3 and treated with TGF-beta. The effects of RUNX3 transfection on cell proliferation and apoptosis were determined. Smad-mediated TGF-beta transcriptional activity was evaluated with the use of dual-luciferase assay. RESULTS: SEG-1 cells are not responsive to TGF-beta. SEG-1 cells lack RUNX3 protein expression, while RUNX3 is highly expressed in normal human gastric and esophageal epithelium. Although the Smad-2 signaling is activated by TGF-beta, SEG-1 cells lack Smad-mediated TGF-beta transcriptional activity. In cells transfected with RUNX3, TGF-beta acquired an antiproliferative effect and induced apoptosis (P = .001). RUNX3 transfection, in the absence of TGF-beta, had no effect on proliferation and apoptosis of SEG-1 cells. RUNX3 expression dramatically increases SMAD-mediated TGF-beta-induced transcriptional activity when compared with controls (P = .0001). CONCLUSIONS: RUNX3 is not expressed in SEG-1 cells, while it is present in normal esophageal mucosa. RUNX3 is essential for the antiproliferative and apoptotic effects of TGF-beta in SEG-1 cells and for the Smad-mediated transcriptional activity of TGF-beta.

Full Text

Duke Authors

Cited Authors

  • Torquati, A; O'rear, L; Longobardi, L; Spagnoli, A; Richards, WO; Daniel Beauchamp, R

Published Date

  • August 2004

Published In

Volume / Issue

  • 136 / 2

Start / End Page

  • 310 - 316

PubMed ID

  • 15300196

Pubmed Central ID

  • 15300196

International Standard Serial Number (ISSN)

  • 0039-6060

Digital Object Identifier (DOI)

  • 10.1016/j.surg.2004.05.005

Language

  • eng

Conference Location

  • United States