Abstract
Cyclooxygenase (COX) consists of two isozymes, COX-1 and COX-2. The roles of these isozymes in the gastrointestinal tract are unknown. We investigated messenger RNA expression of the COX-1 and COX-2 genes in the gastrointestinal cancer cell lines MKN28, MKN45, KATO III CACO-2, DLD-1 and LoVo. These cell lines expressed comparable levels of COX-1 mRNA, although their expression of COX-2 varied. Therefore, we studied the effects of NS-398 and indomethacin, specific and non-specific inhibitors for COX-2, on proliferation of the cell lines. Both of the inhibitors suppressed proliferation of the two cell lines that highly expressed COX-2 (MKN45 and CACO-2). However, these inhibitors exerted minimal effects on proliferation of the other cell lines, which expressed significantly lower levels of COX-2. Therefore, it was proposed that COX-2 participates in proliferation of cancer cells because of over expression of the COX-2 gene.
MeSH terms
-
Cell Division / drug effects*
-
Cell Line
-
Colonic Neoplasms / enzymology
-
Cyclooxygenase 1
-
Cyclooxygenase 2
-
Cyclooxygenase 2 Inhibitors
-
Cyclooxygenase Inhibitors / pharmacology*
-
Gastrointestinal Neoplasms / enzymology*
-
Gene Expression Regulation, Enzymologic
-
Gene Expression Regulation, Neoplastic
-
Humans
-
Indomethacin / pharmacology
-
Isoenzymes / drug effects*
-
Isoenzymes / genetics
-
Membrane Proteins
-
Nitrobenzenes / pharmacology
-
Prostaglandin-Endoperoxide Synthases / drug effects*
-
Prostaglandin-Endoperoxide Synthases / genetics
-
RNA, Messenger / analysis
-
Stomach Neoplasms / enzymology
-
Sulfonamides / pharmacology
-
Tumor Cells, Cultured
Substances
-
Cyclooxygenase 2 Inhibitors
-
Cyclooxygenase Inhibitors
-
Isoenzymes
-
Membrane Proteins
-
Nitrobenzenes
-
RNA, Messenger
-
Sulfonamides
-
N-(2-cyclohexyloxy-4-nitrophenyl)methanesulfonamide
-
Cyclooxygenase 1
-
Cyclooxygenase 2
-
PTGS1 protein, human
-
PTGS2 protein, human
-
Prostaglandin-Endoperoxide Synthases
-
Indomethacin