PT  - JOURNAL ARTICLE
AU  - Williams, Jennie L.
AU  - Nath, Niharika
AU  - Chen, Jie
AU  - Hundley, Thomas R.
AU  - Gao, Jianjun
AU  - Kopelovich, Levy
AU  - Kashfi, Khosrow
AU  - Rigas, Basil
TI  - Growth Inhibition of Human Colon Cancer Cells by Nitric Oxide (NO)-Donating Aspirin Is Associated with Cyclooxygenase-2 Induction and β-Catenin/T-Cell Factor Signaling, Nuclear Factor-κB, and NO Synthase 2 Inhibition
DP  - 2003 Nov 15
TA  - Cancer Research
PG  - 7613--7618
VI  - 63
IP  - 22
4099  - http://cancerres.aacrjournals.org/content/63/22/7613.short
4100  - http://cancerres.aacrjournals.org/content/63/22/7613.full
SO  - Cancer Res2003 Nov 15; 63
AB  - Nitric oxide (NO)-releasing aspirin (ASA), consisting of a traditional ASA molecule to which a NO-donating moiety is covalently bound, is a promising colon cancer chemopreventive agent. NO-ASA inhibits colon cancer cell growth more potently than ASA by inhibiting cell proliferation and enhancing cell killing. We examined in cultured human colon cancer cells the effect of NO-ASA on the β-catenin/T-cell factor signaling pathway, nuclear factor-κB, and NO synthase 2 and on cyclooxygenase (COX) expression, all presumed to participate in colon carcinogenesis. Besides inhibiting cell growth, NO-ASA inhibited the β-catenin/T-cell factor signaling pathway (IC50, 1.1 μm), nuclear factor-κB DNA binding (IC50, 7.5 μm), and NO synthase 2 expression (IC50, 2 μm). Interestingly, NO-ASA induced COX-2 expression, although it had no effect on COX-1. COX-2 induction was accompanied by increased prostaglandin E2 production. These effects occurred at NO-ASA concentrations below or near its IC50 for cell growth (IC50, 2–50 μm). The metabolism of NO-ASA by these cells is characterized by a rapid deacetylation step and the formation of a conjugate with glutathione. NO-ASA had no effect on intracellular cyclic GMP concentrations. We propose a model incorporating the pleiotropic effects of NO-ASA on cell signaling and postulate that collectively these effects may contribute to its strong chemopreventive effect. ©2003 American Association for Cancer Research.