Characterization of Potent SMAC Mimetics that Sensitize Cancer Cells to TNF Family-Induced Apoptosis
| Autor: | John C. Reed, Kristiina Vuori, Stefan J. Riedl, Richard A. Houghten, Kate Welsh, Marcos González-López, Robert Ardecky, Darren Finlay, Shu-ichi Matsuzawa, Peter Teriete, Santhi Ganji, Nicholas D. P. Cosford, Clemencia Pinilla, Snezana Milutinovic |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Physiology Cytotoxicity lcsh:Medicine Apoptosis Toxicology Pathology and Laboratory Medicine Biochemistry Inhibitor of Apoptosis Proteins 0302 clinical medicine Immune Physiology Medicine and Health Sciences lcsh:Science Caspase Innate Immune System Multidisciplinary Cell Death biology Intracellular Signaling Peptides and Proteins Chemical Synthesis Recombinant Proteins 3. Good health XIAP Chemistry Optical Equipment Cell Processes 030220 oncology & carcinogenesis Physical Sciences Cytokines Engineering and Technology Tumor necrosis factor alpha biological phenomena cell phenomena and immunity Research Article Protein Binding Biosynthetic Techniques Immunology Equipment Fluorescence Polarization Research and Analysis Methods Inhibitor of apoptosis Phosphates Mitochondrial Proteins 03 medical and health sciences Cell Line Tumor Protein Concentration Assays Humans Molecular Biology Techniques Molecular Biology Peptide Synthesis Transcription factor Molecular Biology Assays and Analysis Techniques Tumor Necrosis Factor-alpha lcsh:R Molecular Mimicry Chemical Compounds Biology and Life Sciences Proteins Prisms Cell Biology Molecular Development Molecular biology 030104 developmental biology Immune System Cancer cell Cancer research biology.protein lcsh:Q Apoptosis Regulatory Proteins Developmental Biology |
| Zdroj: | PLoS ONE PLoS ONE, Vol 11, Iss 9, p e0161952 (2016) |
| ISSN: | 1932-6203 |
| DOI: | 10.1371/journal.pone.0161952 |
| Popis: | Members of the Inhibitor of APoptosis (IAP) protein family suppress apoptosis within tumor cells, particularly in the context of immune cell-mediated killing by the tumor necrosis factor (TNF) superfamily cytokines. Most IAPs are opposed endogenously by the second mitochondrial activator of caspases (SMAC), which binds to selected baculovirus IAP repeat (BIR) domains of IAPs to displace interacting proteins. The development of SMAC mimetics as novel anticancer drugs has gained impetus, with several agents now in human clinical trials. To further understand the cellular mechanisms of SMAC mimetics, we focused on IAP family members cIAP1 and cIAP2, which are recruited to TNF receptor complexes where they support cell survival through NF-κB activation while suppressing apoptosis by preventing caspase activation. We established fluorescence polarization (FP) assays for the BIR2 and BIR3 domains of human cIAP1 and cIAP2 using fluorochrome-conjugated SMAC peptides as ligands. A library of SMAC mimetics was profiled using the FP assays to provide a unique structure activity relationship (SAR) analysis compared to previous assessments of binding to XIAP. Potent compounds displayed mean inhibitory binding constants (Ki) of 9 to 27 nM against the BIR3 domains of cIAP1 and cIAP2, respectively. Selected compounds were then characterized using cytotoxicity assays in which a cytokine-resistant human tumor cell line was sensitized to either TNF or lymphotoxin-α (LT-α). Cytotoxicity correlated closely with cIAP1 and cIAP2 BIR3 binding activity with the most potent compounds able to reduce cell viability by 50%. Further testing demonstrated that active compounds also inhibit RIP1 binding to BIR3 of cIAP1 and cIAP2 in vitro and reduce steady-state cIAP1 protein levels in cells. Altogether, these data inform the SAR for our SMAC mimetics with respect to cIAP1 and cIAP2, suggesting that these IAP family members play an important role in tumor cell resistance to cytotoxicity mediated by TNF and LT-α. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|