EGF/EGFR axis contributes to the progression of cholangiocarcinoma through the induction of an epithelial-mesenchymal transition.
OBJECTIVE
Epithelial-mesenchymal transition (EMT) is a cellular process involved in cancer progression. The first step of EMT consists in the disruption of E-cadherin-mediated adherens junctions. Cholangiocarcinoma (CCA), a cancer with a poor prognosis due to local invasion and metastasis, displays EMT features. EGFR, a receptor tyrosine kinase, plays a major role in CCA progression. The aim of the study was to determine if EMT is induced by EGFR in CCA cells.


METHODS
In vivo, the expression of E-cadherin was analysed in CCA tumours of 100 patients and correlated with pathological features and EGFR expression, and in a xenograft model in mice treated with gefitinib, an inhibitor of EGFR. In vitro, the regulation of EMT by EGFR was investigated in CCA cell lines.


RESULTS
In human CCA, a cytoplasmic localization of E-cadherin occurred in 50% of the tumours was associated with the peripheral type of CCA, tumour size, the presence of satellite nodules and EGFR overexpression. In xenografted tumours, E-cadherin displayed a cytoplasmic pattern whereas the treatment of mice with gefitinib restored the membranous expression of E-cadherin. In vitro, EGF induced scattering of CCA cells that resulted from the disruption of adherens junctions. Internalization and decreased expression of E-cadherin, as well as nuclear translocation of β-catenin, were observed in EGF-treated CCA cells. In these cells, EMT-transcription factors (i.e., Slug and Zeb-1) and mesenchymal markers (i.e., N-cadherin and α-SMA) were induced, favoring cell invasiveness through cytoskeleton remodeling. All these effects were inhibited by gefitinib.


CONCLUSIONS
The EGF/EGFR axis triggers EMT in CCA cells highlighting the key role of this pathway in CCA progression.
INSERM, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France; UPMC, Univ Paris 06, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France.
Audrey
A
Clapéron
INSERM, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France; UPMC, Univ Paris 06, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France.
Martine
M
Mergey
INSERM, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France; UPMC, Univ Paris 06, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France.
Thanh Huong
TH
Nguyen Ho-Bouldoires
CNRS UMR 144, Institut Curie, F-75005 Paris, France.
Danijela
D
Vignjevic
INSERM, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France; UPMC, Univ Paris 06, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France; AP-HP, Hôpital Saint-Antoine, Service d'Anatomie et Cytologie Pathologiques, F-75012 Paris, France.
Dominique
D
Wendum
INSERM, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France; UPMC, Univ Paris 06, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France.
Yves
Y
Chrétien
INSERM, UMR_S938, Centre de Recherche Saint-Antoine, Plateforme Morphologie du Petit Animal, F-75012 Paris, France.
Fatiha
F
Merabtene
INSERM, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France; UPMC, Univ Paris 06, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France.
Alexandra
A
Frazao
INSERM, UMRS_U773 & AP-HP, Hôpital Beaujon, Service de Pathologie, F-92100 Clichy, France.
Valérie
V
Paradis
INSERM, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France; UPMC, Univ Paris 06, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France.
Chantal
C
Housset
INSERM, UMRS_U773 & AP-HP, Hôpital Beaujon, Service de Pathologie, F-92100 Clichy, France.
Nathalie
N
Guedj
INSERM, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France; UPMC, Univ Paris 06, UMR_S 938, Centre de Recherche Saint-Antoine, F-75012 Paris, France. Electronic address: laura.fouassier@inserm.fr.
Laura
L
Fouassier
D000818:Animals; D001650:Bile Duct Neoplasms / Q000473:pathology*; D001653:Bile Ducts, Intrahepatic; D015820:Cadherins / Q000032:analysis; D045744:Cell Line, Tumor; D002465:Cell Movement; D018281:Cholangiocarcinoma / Q000473:pathology*; D018450:Disease Progression; D004815:Epidermal Growth Factor / Q000502:physiology*; D058750:Epithelial-Mesenchymal Transition; D066246:ErbB Receptors / Q000502:physiology*; D005260:Female; D006801:Humans; D051379:Mice; D009361:Neoplasm Invasiveness
D015820:Cadherins; D004815:Epidermal Growth Factor; C512478:EGFR protein, human; D066246:ErbB Receptors
Cholangiocarcinoma; E-cadherin; EGF; EGFR; Invasion; Migration