Nitrosylcobalamin promotes cell death via S nitrosylation of Apo2L/TRAIL receptor DR4.

Abstract

We have previously demonstrated that nitrosylcobalamin (NO-Cbl), an analogue of vitamin B12 that delivers nitric oxide (NO), had potent antiproliferative activity against several human cancer cell lines. NO-Cbl induced apoptosis via a death receptor/caspase-8 pathway. In this study, we demonstrate that a functional Apo2L/TRAIL receptor was necessary for the induction of cell death by NO-Cbl. Furthermore, the Apo2L/TRAIL death receptor DR4 (TRAIL R1) was S nitrosylated following NO-Cbl treatment. Human melanoma (A375), renal carcinoma (ACHN), and ovarian carcinoma (NIH-OVCAR-3) cells were treated with NO-Cbl and subjected to the biotin switch assay; S-nitrosylated DR4 was detected in all three cell lines. NO-Cbl treatment did not cause S nitrosylation of DR5. The seven cysteine residues located in the cytoplasmic domain of DR4 were individually point mutated to alanines. NIH-OVCAR-3 cells expressing the DR4 C336A mutation lacked S nitrosylation following NO-Cbl treatment. Overexpression of wild-type DR4 sensitized cells to growth inhibition by NO-Cbl. Cells expressing the DR4 C336A mutant were more resistant to NO-Cbl and Apo2L/TRAIL than were the other six C-A mutations or wild-type cells. The C336A mutant also displayed blunted caspase-8 enzymatic activity following NO-Cbl treatment compared to the other mutants. Thus, DR4 residue C336 becomes S nitrosylated and promotes apoptosis following NO-Cbl treatment.

• Authors: Zhuo Tang, Joseph A Bauer, Bei Morrison, Daniel J Lindner
• Journal: Molecular and cellular biology (Mol Cell Biol) Vol. 26 Issue 15 Pg. 5588-94 (Aug 2006) ISSN: 0270-7306 [Print] United States
• PMID: 16847314 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• Nitroso Compounds
• Receptors, TNF-Related Apoptosis-Inducing Ligand
• Receptors, Tumor Necrosis Factor
• Recombinant Proteins
• TNFRSF10A protein, human
• TNFRSF10B protein, human
• nitrosylcobalamin
• CASP8 protein, human
• Caspase 8
• Caspases
• Vitamin B 12

Topics

• Caspase 8
• Caspases (metabolism)
• Cell Death (physiology)
• Cell Line, Tumor
• Cell Proliferation
• Humans
• In Situ Nick-End Labeling
• Nitroso Compounds (metabolism)
• Receptors, TNF-Related Apoptosis-Inducing Ligand
• Receptors, Tumor Necrosis Factor (chemistry, genetics, metabolism)
• Recombinant Proteins (genetics, metabolism)
• Vitamin B 12 (analogs & derivatives, metabolism)