Prostaglandin E2 stimulates Fas ligand expression via the EP1 receptor in colon cancer cells.
Affiliation
Department of Medicine, University College Cork, National University of Ireland, , Clinical Science Building, Cork University Hospital, Wilton, Cork, Ireland.Issue Date
2012-02-03T15:06:06ZMeSH
Blotting, WesternCell Line, Tumor
Coculture Techniques
Colonic Neoplasms/*metabolism/pathology
Dinoprostone/*pharmacology
Enzyme-Linked Immunosorbent Assay
Fas Ligand Protein/genetics/*metabolism
Fluorescent Antibody Technique
Humans
RNA Interference
RNA, Messenger/genetics
Receptors, Prostaglandin E/*metabolism
Receptors, Prostaglandin E, EP1 Subtype
Signal Transduction
Metadata
Show full item recordCitation
Br J Cancer. 2008 Aug 5;99(3):502-12. Epub 2008 Jul 22.Journal
British journal of cancerDOI
10.1038/sj.bjc.6604490PubMed ID
18648368Abstract
Fas ligand (FasL/CD95L) is a member of the tumour necrosis factor superfamily that triggers apoptosis following crosslinking of the Fas receptor. Despite studies strongly implicating tumour-expressed FasL as a major inhibitor of the anti-tumour immune response, little is known about the mechanisms that regulate FasL expression in tumours. In this study, we show that the cyclooxygenase (COX) signalling pathway, and in particular prostaglandin E(2) (PGE(2)), plays a role in the upregulation of FasL expression in colon cancer. Suppression of either COX-2 or COX-1 by RNA interference in HCA-7 and HT29 colon tumour cells reduced FasL expression at both the mRNA and protein level. Conversely, stimulation with PGE(2) increased FasL expression and these cells showed increased cytotoxicity against Fas-sensitive Jurkat T cells. Prostaglandin E(2)-induced FasL expression was mediated by signalling via the EP1 receptor. Moreover, immunohistochemical analysis using serial sections of human colon adenocarcinomas revealed a strong positive correlation between COX-2 and FasL (r=0.722; P<0.0001) expression, and between EP1 receptor and FasL (r=0.740; P<0.0001) expression, in the tumour cells. Thus, these findings indicate that PGE(2) positively regulates FasL expression in colon tumour cells, adding another pro-neoplastic activity to PGE(2).Language
engISSN
1532-1827 (Electronic)0007-0920 (Linking)
ae974a485f413a2113503eed53cd6c53
10.1038/sj.bjc.6604490