Prostaglandin E2 pathway in head and neck squamous cell carcinoma

Background. Prostaglandin E-2 (PGE(2)) is involved in malignant growth. The objective was to study the PGE2 pathway in head and neck squamous cell carcinoma (HNSCC) patients. Methods. Expression of cyclooxygenase (COX) and PGE-synthase isoenzymes, and PGE-receptors was determined in biopsies from 83 patients with HNSCC by real-time reverse transcriptase-polymerase chain reaction (RT-PCR). Results. Expression of COX-2 and cytosolic-PGE-synthase was significantly increased, about 4-fold and 2.5-fold, respectively, in tumors versus paired nontumoral mucosa (n = 34). EP-1 was the only PGE-receptor significantly overexpressed in tumor samples. Expression of COX-1 correlated with mPGES-2 and COX-2 correlated with mPGES-1 (n = 83). Conclusions. COX-2, functionally coordinated with mPGES-1, is likely to be the limiting enzyme in PGE2 biosynthesis in HNSCC. The biological meaning of cPGES/p23 overexpression in HNSCC is not yet clear. Our results support the notion that mPGES-1, cPGES, and EP-1 could be the targets for the development of specific PGE(2)-modifier drugs for HNSCC treatment that could avoid negative side effects of COX-2 selective inhibitors. (c) 2008 Wiley Periodicals, Inc.