Eosinophils in human oral squamous carcinoma; role of prostaglandin D2.
Eosinophils are often predominant inflammatory leukocytes infiltrating oral squamous carcinoma (OSC) sites. Prostaglandins are secreted by oral carcinomas and may be involved in eosinophil infiltration. The objective of this study was to determine the factors contributing to eosinophil migration and potential anti-neoplastic effects on OSC. Eosinophil degranulation was evaluated by measuring release of eosinophil peroxidase (EPO). Eosinophil chemotaxis towards OSC cells was assessed using artificial basement membrane. Eosinophil infiltration was prominent within the tissue surrounding the OSC tumor mass. We observed growth inhibition of the OSC cell line, SCC-9, during co-culture with human eosinophils, in vitro, which correlated with EPO activity that possesses growth inhibitory activity. The PGD2 synthase inhibitor, HQL-79, abrogated migration towards SCC-9. Our data suggest that OSC-derived PGD2 may play an important role via CRTH2 (the PGD2 receptor on eosinophils) in eosinophil recruitment and subsequent anti-tumor activity through the action of eosinophil cationic proteins.
Pulmonary Research Group, University of Alberta, 559 Heritage Medical Research Centre, Edmonton, Alberta T6G 2S2, Canada. fdavoine@ualberta.ca.
Francis
F
Davoine
Adrian
A
Sim
Charlie
C
Tang
Sibina
S
Fisher
Caroline
C
Ethier
Lakshmi
L
Puttagunta
Yingqi
Y
Wu
W Tim
WT
McGaw
Donald
D
Yu
Lisa
L
Cameron
Darryl J
DJ
Adamko
Redwan
R
Moqbel