Crystal structures of prostaglandin D(2) 11-ketoreductase (AKR1C3) in complex with the nonsteroidal anti-inflammatory drugs flufenamic acid and indomethacin.Lovering, A.L., Ride, J.P., Bunce, C.M., Desmond, J.C., Cummings, S.M., White, S.A.
(2004) Cancer Res. 64: 1802-1810
- PubMed: 14996743
- Primary Citation of Related Structures:
- PubMed Abstract:
It is becoming increasingly well established that nonsteroidal anti-inflammatory drugs (NSAID) protect against tumors of the gastrointestinal tract and that they may also protect against a variety of other tumors. These activities have been widely at ...
It is becoming increasingly well established that nonsteroidal anti-inflammatory drugs (NSAID) protect against tumors of the gastrointestinal tract and that they may also protect against a variety of other tumors. These activities have been widely attributed to the inhibition of cylooxygenases (COX) and, in particular, COX-2. However, several observations have indicated that other targets may be involved. Besides targeting COX, certain NSAID also inhibit enzymes belonging to the aldo-keto reductase (AKR) family, including AKR1C3. We have demonstrated previously that overexpression of AKR1C3 acts to suppress cell differentiation and promote proliferation in myeloid cells. However, this enzyme has a broad tissue distribution and therefore represents a novel candidate for the target of the COX-independent antineoplastic actions of NSAID. Here we report on the X-ray crystal structures of AKR1C3 complexed with the NSAID indomethacin (1.8 A resolution) or flufenamic acid (1.7 A resolution). One molecule of indomethacin is bound in the active site, whereas flufenamic acid binds to both the active site and the beta-hairpin loop, at the opposite end of the central beta-barrel. Two other crystal structures (1.20 and 2.1 A resolution) show acetate bound in the active site occupying the proposed oxyanion hole. The data underline AKR1C3 as a COX-independent target for NSAID and will provide a structural basis for the future development of new cancer therapies with reduced COX-dependent side effects.
The School of Biosciences, The University of Birmingham, Birmingham, United Kingdom.