Your browser version may not work well with NCBI's Web applications. More information here...
Related Articles, Links
Click here to read Click here to read
The mechanism of action of nitric oxide-donating aspirin.

Kashfi K, Rigas B.

Department of Physiology and Pharmacology, City University of New York Medical School, New York, NY 10031, USA. Kashfi@med.cuny.edu

NO-donating aspirin (NO-ASA) is a promising anticancer drug. We studied the contribution of NO-ASA's components (ASA, NO-releasing moiety, and spacer linking them) to its effect. The ASA and NO-releasing moieties play no biological role: ASA inhibits the growth of colon cancer cells >100-fold less potently that NO-ASA; and denitrated NO-ASA plus the NO-donor SNAP releasing the same amount of NO as NO-ASA, inhibit the growth of cancer cells >50-fold less potently than NO-ASA. The biologically active moiety of NO-ASA is the spacer: it is chemically reactive (studies with NO-ASA radiolabeled at the spacer demonstrated that it binds to proteins); and compounds in which the ASA or the NO-releasing groups are replaced inhibit cell growth similar to NO-ASA. We propose a mechanism of action of NO-ASA involving formation of quinone methide from its para and ortho isomers and of a carbocation from the meta, with the NO-releasing group functioning as a leaving group.

PMID: 17512900 [PubMed - indexed for MEDLINE]