TY - JOUR
T1 - RUNX3 inhibits cell proliferation and induces apoptosis by reinstating transforming growth factor beta responsiveness in esophageal adenocarcinoma cells
AU - Torquati, Alfonso
AU - O'Rear, Lynda
AU - Longobardi, Lara
AU - Spagnoli, Anna
AU - Richards, William O.
AU - Daniel Beauchamp, R.
PY - 2004/8
Y1 - 2004/8
N2 - Background SEG-1, a Barrett's-derived esophageal adenocarcinoma cell line, is not responsive to transforming growth factor beta (TGF-β) 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-β. Methods RUNX3 expression was assessed by immunoblotting. SEG-1 cells were transfected with RUNX3 and treated with TGF-β. The effects of RUNX3 transfection on cell proliferation and apoptosis were determined. Smad-mediated TGF-β transcriptional activity was evaluated with the use of dual-luciferase assay. Results SEG-1 cells are not responsive to TGF-β. 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-β, SEG-1 cells lack Smad-mediated TGF-β transcriptional activity. In cells transfected with RUNX3, TGF-β acquired an antiproliferative effect and induced apoptosis (P=.001). RUNX3 transfection, in the absence of TGF-β, had no effect on proliferation and apoptosis of SEG-1 cells. RUNX3 expression dramatically increases SMAD-mediated TGF-β-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-β in SEG-1 cells and for the Smad-mediated transcriptional activity of TGF-β.
AB - Background SEG-1, a Barrett's-derived esophageal adenocarcinoma cell line, is not responsive to transforming growth factor beta (TGF-β) 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-β. Methods RUNX3 expression was assessed by immunoblotting. SEG-1 cells were transfected with RUNX3 and treated with TGF-β. The effects of RUNX3 transfection on cell proliferation and apoptosis were determined. Smad-mediated TGF-β transcriptional activity was evaluated with the use of dual-luciferase assay. Results SEG-1 cells are not responsive to TGF-β. 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-β, SEG-1 cells lack Smad-mediated TGF-β transcriptional activity. In cells transfected with RUNX3, TGF-β acquired an antiproliferative effect and induced apoptosis (P=.001). RUNX3 transfection, in the absence of TGF-β, had no effect on proliferation and apoptosis of SEG-1 cells. RUNX3 expression dramatically increases SMAD-mediated TGF-β-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-β in SEG-1 cells and for the Smad-mediated transcriptional activity of TGF-β.
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U2 - 10.1016/j.surg.2004.05.005
DO - 10.1016/j.surg.2004.05.005
M3 - Article
C2 - 15300196
AN - SCOPUS:3843072194
VL - 136
SP - 310
EP - 316
JO - Surgery (United States)
JF - Surgery (United States)
SN - 0039-6060
IS - 2
ER -