CXCR7 expression in esophageal cancer.
BACKGROUND
The chemokine CXCL12 and its receptor CXCR4 play a major role in tumor invasion, proliferation and metastasis in different malignant diseases, including esophageal carcinoma, amongst others. CXCR7 was recently identified as a novel alternate receptor for CXCL12. The aim of this study was to evaluate the prognostic impact of expression of chemokine receptor CXCR7 in patients with esophageal carcinoma (EC).


METHODS
Expression of CXCR7 in primary tumors, lymph nodes and distant metastases of 299 patients with EC was evaluated by immunohistochemistry on a tissue microarray and compared with clinical and histopathological data.


RESULTS
In esophageal cancer sections, CXCR7-specific reactivity was apparent in 45% of the squamous cell carcinomas (ESCC), but only occasionally in adenocarcinomas. No correlation between CXCR4 and CXCR7 expression was evident. We correlated expression with clinical and histopathological characteristics, but could not find any association.


CONCLUSIONS
Contrary to the other known CXCL12 receptor, CXCR4, CXCR7 is expressed in ESCC only, underlining the divergent mechanisms and backgrounds of EAC and ESCC. The results of the study do not indicate a significant functional role for CXCR7 in EAC or ESCC of the esophagus. However, its variable expression in the main two main types of EC needs to be further investigated.
Department of General, Visceral and Thoracic Surgery, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany. m.tachezy@uke.de.
Michael
M
Tachezy
Hilke
H
Zander
Florian
F
Gebauer
Katharina
K
von Loga
Klaus
K
Pantel
Jakob R
JR
Izbicki
Maximilian
M
Bockhorn
D000230:Adenocarcinoma / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000378:metabolism / Q000473:pathology; D004938:Esophageal Neoplasms / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D053208:Kaplan-Meier Estimate; D008198:Lymph Nodes / Q000378:metabolism / Q000473:pathology; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D054387:Receptors, CXCR / Q000378:metabolism*
C501896:ACKR3 protein, human; D054387:Receptors, CXCR