Acta Pharmacologica Sinica (2010) 31: 211–218; doi: 10.1038/aps.2009.184

Acta Pharmacologica Sinica (2010) 31: 211–218; doi: 10.1038/aps.2009.184

Original Article

The epoxyeicosatrienoic acid-stimulated phosphorylation of EGF-R involves the activation of metalloproteinases and the release of HB-EGF in cancer cells

Li-ming CHENG^1,#, Jian-gang JIANG^1,#, Zi-yong SUN¹, Chen CHEN¹, Ryan T DACKOR², Darryl C ZELDIN², Dao-wen WANG^1,*

¹The Institute of Hypertension and Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; ²Division of Intramural Research, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC 27709, USA

Aim: To test the hypothesis that the epoxyeicosatrienoic acid (EET)-induced transactivation of EGF-R depends on the activation of metalloproteinases and the subsequent release of HB-EGF in cancer cells.

Methods: Exogenous 14,15-EET were added to four human-derived cancer cell lines Tca-8113, A549, HepG2, and MDA-MB-231, or these same cell lines were transfected with a mutant CYP epoxygenase (CYP102 F87V, an active 14,15-epoxygenase). The effects of elevated EET levels on the phosphorylation of tyrosine residues in the EGF receptor and on ERK1/2 activation were then assessed.

Results: Both the addition of 14,15-EET and the transfection of cells with CYP102 F87V markedly increased the phosphorylation of the tyrosine residues of EGF-R and ERK1/2, an effect that was blocked by a selective EGF-R tyrosine kinase inhibitor (tyrphostin AG1478), a broad-spectrum metalloproteinase inhibitor (1,10-phenanthroline), and an inhibitor of HB-EGF release (CRM197) in Tca-8113 cells. In addition, AG1478, 1,10-phenanthroline, and CRM197 also inhibited the tyrosine phosphorylation of EGF-R and ERK1/2 that was induced by 14,15-EET in the A549, HepG2, and MDA-MB-231 cell lines.

Conclusion: These results suggest that the EET-induced transactivation of EGF-R depends on activation of metalloproteinases and the subsequent release of HB-EGF in cancer cell lines.

Keywords: arachidonic acid; cytochrome P450 epoxygenase; epoxyeicosatrienoic acids; tumor cell proliferation; EGF-R; ERK1/2; AG1478; phenanthroline; CRM197; metalloproteinase

This work was supported by the International Collaboration Project (No 2005DFA30880), the 973 grant (2007CB512004), and two National Natural Science Foundation of China grant (30430320, 30770882). This work was also funded, in part, by the Intramural Research Program of the NIH and the National Institute of Environmental Health Sciences (Z01 ES025034).

^#The first two authors contributed equally to this work.
^*To whom correspondence should be addressed.
E-mail dwwang@tjh.tjmu.edu.cn
Received 2009-07-18 Accepted 2009-11-19

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