T-614, a novel antirheumatic drug, inhibits both the activity and induction of cyclooxygenase-2 (COX-2) in cultured fibroblasts.
To elucidate the mechanism for the selective inhibition of prostaglandin E2 (PGE2) production in inflammatory tissue by T-614 (3-formylamino-7-methylsulfonylamino-6-phenoxy-4H-1-benzopyran-4-o ne), its effects on both the activity and the induction of cyclooxygenase (COX)-2 were investigated in vitro. T-614 inhibited the activity of purified COX-2 enzyme (IC50: 7.7 micrograms/ml), but was inactive against both COX-1 activities of microsomal and purified enzymes (IC50: > 300 micrograms/ml). On the other hand, when the inhibition of PGE2 production by T-614 was examined in the cultured fibroblasts stimulated with bradykinin, T-614 at 1 microgram/ml or less inhibited PGE2 release more effectively than that in the above cell-free system. Therefore, we examined which of the COX enzymes was expressed in bradykinin-stimulated fibroblasts by using both the reverse transcriptase-polymerase chain reaction (RT-PCR) and Northern blot analyses. As a result, COX-1 mRNA was constitutively expressed in the cells, whereas COX-2 mRNA was not detected without stimulation with bradykinin, but was expressed within 30 min when stimulated. Furthermore, it was found that the addition of T-614 reduced the COX-2 mRNA levels in 30 min after stimulation. These studies suggest that at least some of inhibitory effects of T-614 on prostanoids production are mediated by the synergy of the inhibition of COX-2 activity and the inhibition of induction, and such an action of T-614 may explain the pharmacological properties of this drug.
Tanaka
K
K
Research Laboratories, Toyama Chemical Co., Ltd., Japan.
Kawasaki
H
H
Kurata
K
K
Aikawa
Y
Y
Tsukamoto
Y
Y
Inaba
T
T
D016475:3T3 Cells / Q000166:cytology / Q000187:drug effects; D000199:Actins / Q000235:genetics / Q000378:metabolism; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D001483:Base Sequence; D001578:Benzopyrans / Q000494:pharmacology*; D015152:Blotting, Northern; D001920:Bradykinin / Q000494:pharmacology; D002478:Cells, Cultured; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D017931:DNA Primers / Q000737:chemistry; D015232:Dinoprostone / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D004790:Enzyme Induction / Q000187:drug effects; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects*; D015971:Gene Expression Regulation, Enzymologic; D066298:In Vitro Techniques; D051379:Mice; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011451:Prostaglandin-Endoperoxide Synthases / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D013449:Sulfonamides / Q000494:pharmacology*
D000199:Actins; D000894:Anti-Inflammatory Agents, Non-Steroidal; D001578:Benzopyrans; D016861:Cyclooxygenase Inhibitors; D017931:DNA Primers; D013449:Sulfonamides; C077313:T 614; D011451:Prostaglandin-Endoperoxide Synthases; D015232:Dinoprostone; D001920:Bradykinin