title: Significance of COX-2 expression in human esophageal squamous cell carcinoma.
abstract: Cyclooxygenase-2 (COX-2) is well established to play an important role in the tumorigenesis of a variety of human cancers; however, the function of COX-2 in the development of esophageal squamous cell carcinoma (ESCC) remains less clear. Here, we determined, first, the pattern of COX-2 expression in normal esophageal mucosa, dysplasia, carcinoma in situ (CIS) and invasive SCC. Immunohistochemical analysis showed that, while COX-2 was weakly expressed, if at all, in normal squamous epithelium, strong COX-2 expression was detected as early as the stage of dysplasia and frequently in 20 of 26 (77%) CIS and 86 of 111 (77%) invasive SCC. Upregulation of COX-2 in ESCC was found to be significantly associated with tumor progression (R = 0.493, P < 0.01). Further, treatment of human ESCC cell lines (KYSE450 and KYSE510) with NS-398, a COX-2 specific chemical inhibitor, suppressed the production of prostaglandin E2 (PGE2) and induced cell growth inhibition, cell cycle arrest at the G1-S checkpoint, and the expression of cyclin-dependent kinase inhibitors p21waf1/cip1 and p27kip1. Finally, knockdown expression of COX-2 in KYSE450 cells by a specific COX-2 siRNA dramatically inhibited PGE2 production, cell growth and, more importantly, colony formation and tumorigenesis in nude mice. Together, this study suggested that COX-2 may be involved in an early stage of squamous cell carcinogenesis of the esophagus and has a non-redundant role in the regulation of cellular proliferation and tumorigenesis of esophageal epithelial cells.
authors.affiliation: National Laboratory of Molecular Oncology, Cancer Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, People's Republic of China.
authors.forename: Huiying
authors.initials: H
authors.lastname: Zhi
authors.forename: Lin
authors.initials: L
authors.lastname: Wang
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
authors.forename: Chuannong
authors.initials: C
authors.lastname: Zhou
authors.forename: Fang
authors.initials: F
authors.lastname: Ding
authors.forename: Aiping
authors.initials: A
authors.lastname: Luo
authors.forename: Min
authors.initials: M
authors.lastname: Wu
authors.forename: Qimin
authors.initials: Q
authors.lastname: Zhan
authors.forename: Zhihua
authors.initials: Z
authors.lastname: Liu
mesh_terms: D000818:Animals; D002294:Carcinoma, Squamous Cell / Q000201:enzymology*; D045744:Cell Line, Tumor; D051546:Cyclooxygenase 2 / Q000096:biosynthesis*; D015232:Dinoprostone / Q000378:metabolism; D018450:Disease Progression; D004938:Esophageal Neoplasms / Q000201:enzymology* / Q000473:pathology; D004947:Esophagus / Q000473:pathology; D005260:Female; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D009578:Nitrobenzenes / Q000494:pharmacology; D034741:RNA, Small Interfering / Q000378:metabolism; D013449:Sulfonamides / Q000494:pharmacology
chemical_list: D009578:Nitrobenzenes; D034741:RNA, Small Interfering; D013449:Sulfonamides; C080955:N-(2-cyclohexyloxy-4-nitrophenyl)methanesulfonamide; D051546:Cyclooxygenase 2; D015232:Dinoprostone