Abstract

Integrin α6β4 is up-regulated in pancreatic adenocarcinomas where it contributes to carcinoma cell invasion by altering the transcriptome. In this study, we found that integrin α6β4 up-regulates several genes in the epidermal growth factor receptor (EGFR) pathway, including amphiregulin (AREG), epiregulin (EREG), and ectodomain cleavage protease MMP1, which is mediated by promoter demethylation and NFAT5. The correlation of these genes with integrin α6β4 was confirmed in The Cancer Genome Atlas Pancreatic Cancer Database. Based on previous observations that integrin α6β4 cooperates with c-Met in pancreatic cancers, we examined the impact of EGFR signaling on hepatocyte growth factor (HGF)-stimulated migration and invasion. We found that AREG and EREG were required for autocrine EGFR signaling, as knocking down either ligand inhibited HGF-mediated migration and invasion. We further determined that HGF induced secretion of AREG, which is dependent on integrin-growth factor signaling pathways, including MAPK, PI3K, and PKC. Moreover, matrix metalloproteinase activity and integrin α6β4 signaling were required for AREG secretion. Blocking EGFR signaling with EGFR-specific antibodies or an EGFR tyrosine kinase inhibitor hindered HGF-stimulated pancreatic carcinoma cell chemotaxis and invasive growth in three-dimensional culture. Finally, we found that EGFR was phosphorylated in response to HGF stimulation that is dependent on EGFR kinase activity; however, c-Met phosphorylation in response to HGF was unaffected by EGFR signaling. Taken together, these data illustrate that integrin α6β4 stimulates invasion by promoting autocrine EGFR signaling through transcriptional up-regulation of key EGFR family members and by facilitating HGF-stimulated EGFR ligand secretion. These signaling events, in turn, promote pancreatic carcinoma migration and invasion.

Document Type

Article

Publication Date

11-6-2015

Notes/Citation Information

Published in The Journal of Biological Chemistry, v. 290, no. 45, p. 27228-27238.

This research was originally published in The Journal of Biological Chemistry. Brittany L. Carpenter, Min Chen, Teresa Knifley, Kelley A. Davis, Susan M. W. Harrison, Rachel L. Stewart, and Kathleen L. O’Connor. Integrin α6β4 Promotes Autocrine Epidermal Growth Factor Receptor (EGFR) Signaling to Stimulate Migration and Invasion toward Hepatocyte Growth Factor (HGF). The Journal of Biological Chemistry. 2015; 290:27228-27238. © the American Society for Biochemistry and Molecular Biology.

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Digital Object Identifier (DOI)

https://doi.org/10.1074/jbc.M115.686873

Funding Information

This work was supported by National Institutes of Health Grants T32 CA165990 (to B. L. C.), T32 CA160003 (to R. L. S.), IRG-85-001-25 (to M. C.), and R01 CA109136 (to K. L. O. and M. C.). The authors declare that they have no conflicts of interest with the contents of this article.

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