Temporal relationship between induction of mutant Ha-Ras and upregulation of EGF receptor ligands and cyclooxygenase-2 in rat intestinal epithelial cells

2001 ◽  
Vol 120 (5) ◽  
pp. A494-A494
Author(s):  
M LU ◽  
R COFFEYJR ◽  
D BEAUCHAMP
2003 ◽  
Vol 124 (4) ◽  
pp. A14
Author(s):  
Ji-Zhong Cheng ◽  
Yan-Shi Guo ◽  
Mark R. Hellmich ◽  
Courtney M. Townsend

2006 ◽  
Vol 36 (9) ◽  
pp. 2446-2456 ◽  
Author(s):  
Jung Mogg Kim ◽  
Jin Young Lee ◽  
Young Mee Yoon ◽  
Yu-Kyoung Oh ◽  
Ju Seop Kang ◽  
...  

2003 ◽  
Vol 124 (4) ◽  
pp. A597
Author(s):  
Frederick S. Huang ◽  
Yumei Ye ◽  
Felicitas L. Marquart ◽  
Dai H. Chung ◽  
B. Mark Evers

Oncogene ◽  
2002 ◽  
Vol 21 (47) ◽  
pp. 7175-7186 ◽  
Author(s):  
Stanley CW Ko ◽  
Keith S Chapple ◽  
Gillian Hawcroft ◽  
P Louise Coletta ◽  
Alexander F Markham ◽  
...  

2007 ◽  
Vol 292 (1) ◽  
pp. G39-G52 ◽  
Author(s):  
Masahiro Iizuka ◽  
Kenji Sasaki ◽  
Yohei Hirai ◽  
Kenichi Shindo ◽  
Shiho Konno ◽  
...  

Epimorphin is a mesenchymal protein that regulates morphogenesis of epithelial cells. Our preliminary study suggested a novel function of epimorphin in enhancing survival of intestinal epithelial cells (IEC). Oxidative stress leads to cell injury and death and is suggested to be a key contributor to pathogenesis of inflammatory bowel disease. This study was conducted to determine whether epimorphin protects IEC from oxidative stress. Rat intestinal epithelial cell line IEC-6 was cultured with epimorphin (10 and 20 μg/ml), and the life span of IEC was assessed. The mean life span of IEC-6 cells was prolonged 1.9-fold ( P < 0.0006) by treatment with epimorphin. We then examined the epimorphin signaling pathways. Epimorphin phosphorylated epidermal growth factor (EGF) receptor, activated the MEK/extracellular signal-regulated kinase 1/2 mitogen-activated protein kinase and phosphatidylinositol 3 (PI3) kinase/Akt pathways, phosphorylated Bad, and induced Bcl-XL and survivin. Hydrogen peroxide (1 mM) induced cell death in 92% of IEC-6 cells, but epimorphin dramatically diminished (88.7%) cell death induced by hydrogen peroxide ( P < 0.0001). This protective effect of epimorphin was significantly attenuated by inhibitors of MEK and PI3 kinase ( P < 0.0001) or EGF receptor-neutralizing antibody ( P = 0.0007). In wound assays, the number of migrated cells in the wound area decreased (72.5%) by treatment with 30 μM hydrogen peroxide, but epimorphin increased the number of migrated cells 3.18-fold ( P < 0.0001). These results support a novel function of epimorphin in protecting IEC from oxidative stress. This anti-oxidative function of epimorphin is dramatic and is likely mediated by the activation of EGF receptors and the MEK/extracellular signal-regulated kinase and PI3 kinase/Akt signaling pathways and through the induction of anti-apoptotic factors.


1994 ◽  
Vol 267 (5) ◽  
pp. G843-G850 ◽  
Author(s):  
S. Oguchi ◽  
W. A. Walker ◽  
I. R. Sanderson

Previous reports have shown that gastrointestinal epithelial cells produce insulin-like growth factor-binding proteins (IGF-BP), which modulate the actions of IGF. This study aims to examine the relationship between differentiation and IGF-BP secretion by human intestinal epithelial cells and the effect of growth factors on their production. Caco-2 cells were cultured in serum-free media. IGF-BP secretion into the incubation media was analyzed by Western ligand blotting and immunoblotting. Caco-2 cells produced IGF-BP-2, IGF-BP-3, and IGF-BP-4. Secretion of IGF-BP-2 and IGF-BP-3 increased with differentiation, but IGF-BP-4 secretion diminished. The effect of exogenous growth factors on IGF-BP secretion was maximal at earlier stages of differentiation. IGF-I stimulated mainly IGF-BP-3 production, but epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-alpha) stimulated predominantly IGF-BP-4 secretion. Adding an anti-EGF receptor antibody to block autocrine TGF-alpha activity inhibited IGF-BP-4 production but stimulated IGF-BP-2 and IGF-BP-3. In conclusion, the profile of IGF-BP secretion changes with differentiation. IGF-I and EGF (or TGF-alpha) stimulate different types of IGF-BP, with autocrine TGF-alpha activity being a factor affecting IGF-BP production during differentiation.


2002 ◽  
Vol 277 (50) ◽  
pp. 48755-48763 ◽  
Author(s):  
Yan-Shi Guo ◽  
Ji-Zhong Cheng ◽  
Gui-Fang Jin ◽  
J. Silvio Gutkind ◽  
Mark R. Hellmich ◽  
...  

2007 ◽  
Vol 574 (2-3) ◽  
pp. 85-93 ◽  
Author(s):  
Bénédicte Buffin-Meyer ◽  
Pierre-Antoine Crassous ◽  
Christine Delage ◽  
Colette Denis ◽  
Stéphane Schaak ◽  
...  

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