A Novel Kinase Inhibitor of FADD Phosphorylation Chemosensitizes through the Inhibition of NF-kappa B

Department of Radiation Oncology, University of Michigan, Ann Arbor, MI 48109, USA.
Molecular Cancer Therapeutics (Impact Factor: 5.68). 08/2011; 10(10):1807-17. DOI: 10.1158/1535-7163.MCT-11-0362
Source: PubMed


Fas-associated protein with death domain (FADD) is a cytosolic adapter protein essential for mediating death receptor-induced apoptosis. It has also been implicated in a number of nonapoptotic activities including embryogenesis, cell-cycle progression, cell proliferation, and tumorigenesis. Our recent studies have shown that high levels of phosphorylated FADD (p-FADD) in tumor cells correlate with increased activation of the antiapoptotic transcription factor NF-κB and is a biomarker for aggressive disease and poor clinical outcome. These findings suggest that inhibition of FADD phosphorylation is a viable target for cancer therapy. A high-throughput screen using a cell-based assay for monitoring FADD-kinase activity identified NSC 47147 as a small molecule inhibitor of FADD phosphorylation. The compound was evaluated in live cells and mouse tumors for its efficacy as an inhibitor of FADD-kinase activity through the inhibition of casein kinase 1α. NSC 47147 was shown to decrease levels of p-FADD and NF-κB activity such that combination therapy leads to greater induction of apoptosis and enhanced tumor control than either agent alone. The studies described here show the utility of bioluminescent cell-based assays for the identification of active compounds and the validation of drug-target interaction in a living subject. In addition, the presented results provide proof-of-principle studies as to the validity of targeting FADD-kinase activity as a novel cancer therapy strategy.

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