H(2)O(2) preferentially synergizes with nitroprusside to induce apoptosis associated with superoxide dismutase dysregulation in human melanoma irrespective of p53 status: Antagonism by o-phenanthroline
| Autor: | Luis A. Gomez-Sarosi, Mary Strasberg-Rieber, Manuel Rieber |
|---|---|
| Rok vydání: | 2010 |
| Předmět: |
inorganic chemicals
Nitroprusside Genotype SOD1 SOD2 Apoptosis Toxicology medicine.disease_cause Superoxide dismutase chemistry.chemical_compound Nitroferricyanide medicine Humans Melanoma Cell Proliferation chemistry.chemical_classification Reactive oxygen species biology Chemistry Superoxide Dismutase Drug Synergism General Medicine Hydrogen Peroxide Molecular biology Biochemistry Toxicity biology.protein Ferricyanide Tumor Suppressor Protein p53 Oxidative stress Phenanthrolines |
| Zdroj: | Chemico-biological interactions. 188(1) |
| ISSN: | 1872-7786 |
| Popis: | The pro-oxidant hydrogen peroxide (H(2)O(2)) is converted to a reactive oxygen species by transition metals like iron. Since mutations in the p53 tumor suppressor gene contribute to drug resistance, we used genetically-matched human C8161 melanoma harbouring wt or DN-R175H mutant p53, to investigate the influence of p53 status on the potentiation of H(2)O(2) toxicity by: (a) intact sodium nitroprusside or nitroferricyanide (SNP), (b) its light-exhausted NO-depleted form (lex-SNP), (c) potassium ferricyanide, or (d) ferric ammonium sulphate. Whereas single treatments with SNP or H(2)O(2) were partly cytotoxic, preferentially potentiation of H(2)O(2) toxicity was evidenced with intact or lex-SNP. No comparable increase of H(2)O(2) toxicity was induced by ferricyanide, ferric ammonium sulphate or S-nitroso-N-acetyl penicillamine (SNAP), a known NO donor lacking iron. Immune blotting revealed apoptosis-associated PARP cleavage induced by [SNP+H(2)O(2)] irrespective of p53 status. This correlated with an eightfold induction of [Mn-SOD; SOD2] in wt p53 melanoma cells, and with a super-induction of the same enzyme reciprocal with loss of [Cu,Zn-SOD; SOD1], in mutant p53 cells. All these changes were antagonized by the anti-oxidant N-acetylcysteine or the iron chelator o-phenanthroline. We hypothesize that superoxide dismutase imbalance and iron-dependent redox changes involving OH species generated from a Fenton reaction between [SNP+H(2)O(2)], may be important in this anti-tumor activity. Although tumor drug resistance is frequently associated with DN-p53 mutations, our data shows for the first time the preferential ability of SNP to enhance H(2)O(2) toxicity, irrespective of p53 status. |
| Databáze: | OpenAIRE |
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