The Cell Surface Glycoprotein CUB Domain-containing Protein 1 (CDCP1) Contributes to Epidermal Growth Factor Receptor-mediated Cell Migration

Ying Dong,Yaowu He,Leonore De Boer,M Sharon Stack,John W Lumley,Judith A Clements,John D Hooper

doi:10.1074/jbc.m111.335448

Abstract

Epidermal growth factor (EGF) activation of the EGF receptor (EGFR) is an important mediator of cell migration, and aberrant signaling via this system promotes a number of malignancies including ovarian cancer. We have identified the cell surface glycoprotein CDCP1 as a key regulator of EGF/EGFR-induced cell migration. We show that signaling via EGF/EGFR induces migration of ovarian cancer Caov3 and OVCA420 cells with concomitant up-regulation of CDCP1 mRNA and protein. Consistent with a role in cell migration CDCP1 relocates from cell-cell junctions to punctate structures on filopodia after activation of EGFR. Significantly, disruption of CDCP1 either by silencing or the use of a function blocking antibody efficiently reduces EGF/EGFR-induced cell migration of Caov3 and OVCA420 cells. We also show that up-regulation of CDCP1 is inhibited by pharmacological agents blocking ERK but not Src signaling, indicating that the RAS/RAF/MEK/ERK pathway is required downstream of EGF/EGFR to induce increased expression of CDCP1. Our immunohistochemical analysis of benign, primary, and metastatic serous epithelial ovarian tumors demonstrates that CDCP1 is expressed during progression of this cancer. These data highlight a novel role for CDCP1 in EGF/EGFR-induced cell migration and indicate that targeting of CDCP1 may be a rational approach to inhibit progression of cancers driven by EGFR signaling including those resistant to anti-EGFR drugs because of activating mutations in the RAS/RAF/MEK/ERK pathway.

Highlights

Epidermal growth factor (EGF) activates EGF receptor (EGFR) to promote cell migration and cancer
CDCP1 Is Up-regulated by EGF/EGFR Signaling Axis—To identify cell lines suitable for examination of the role of CDCP1 in EGF/EGFR-mediated cell migration, we first analyzed the expression of CDCP1 in 10 epithelial ovarian cancer-derived cell lines
We have demonstrated that disruption of CDCP1 either by silencing or the use of a function blocking antibody substantially reduces the ability of EGF/EGFR to induce migration of ovarian cancer Caov3 and OVCA420 cells

Summary

Background

Epidermal growth factor (EGF) activates EGF receptor (EGFR) to promote cell migration and cancer. Our immunohistochemical analysis of benign, primary, and metastatic serous epithelial ovarian tumors demonstrates that CDCP1 is expressed during progression of this cancer These data highlight a novel role for CDCP1 in EGF/ EGFR-induced cell migration and indicate that targeting of CDCP1 may be a rational approach to inhibit progression of cancers driven by EGFR signaling including those resistant to anti-EGFR drugs because of activating mutations in the RAS/ RAF/MEK/ERK pathway. Ligand-mediated activation of EGFR requires binding by one of at least six growth factors, including epidermal growth factor (EGF), to the receptor extracellular domain [3, 4], which initiates autophosphorylation of specific receptor cytoplasmic tyrosine residues, including tyrosine 1068 [5] This triggers further signaling events, including activation of RAS/RAF/MEK/ERK [6, 7] and Src family kinase (SFK) (8 –13) pathways, which promote a range of cellular processes including migration (14 –16). Targeting of CDCP1 may be a rational approach to inhibit malignancies, such as ovarian cancer, that are driven by EGF/EGFR

EXPERIMENTAL PROCEDURES

RESULTS

DISCUSSION