skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Protein nitration and nitrosylation by NO-donating aspirin in colon cancer cells: Relevance to its mechanism of action

Journal Article · · Experimental Cell Research
; ;  [1];  [2];  [1]
  1. Division of Cancer Prevention, Stony Brook University, HSC, T17-080, Stony Brook, NY 11794-8173 (United States)
  2. Division of Cancer Prevention NCI, NIH, Bethesda, MD (United States)

Nitric oxide-donating aspirin (NO-ASA) is a promising agent for cancer prevention. Although studied extensively, its molecular targets and mechanism of action are still unclear. S-nitrosylation of signaling proteins is emerging as an important regulatory mechanism by NO. Here, we examined whether S-nitrosylation of the NF-{kappa}B, p53, and Wnt signaling proteins by NO-ASA might explain, in part, its mechanism of action in colon cancer. NO-ASA releases significant amounts of NO detected intracellularly in HCT116 and HT-29 colon cells. Using a modified biotin switch assay we demonstrated that NO-ASA S-nitrosylates the signaling proteins p53, {beta}-catenin, and NF-{kappa}B, in colon cancer cells in a time- and concentration-dependent manner. NO-ASA suppresses NF-{kappa}B binding to its cognate DNA oligonucleotide, which occurs without changes in the nuclear levels of the NF-{kappa}B subunits p65 and p50 and is reversed by dithiothreitol that reduces -S-NO to -SH. In addition to S-nitrosylation, we documented both in vitro and in vivo widespread nitration of tyrosine residues of cellular proteins in response to NO-ASA. Our results suggest that the increased intracellular NO levels following treatment with NO-ASA modulate cell signaling by chemically modifying key protein members of signaling cascades. We speculate that S-nitrosylation and tyrosine nitration are responsible, at least in part, for the inhibitory growth effect of NO-ASA on cancer cell growth and that this may represent a general mechanism of action of NO-releasing agents.

OSTI ID:
22212136
Journal Information:
Experimental Cell Research, Vol. 317, Issue 10; Other Information: Copyright (c) 2011 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0014-4827
Country of Publication:
United States
Language:
English