Investigation of 3-aryl-pyrimido[5,4-e][1,2,4]triazine-5,7-diones as small molecule antagonists of β-catenin/TCF transcription
摘要:
Nearly all colorectal cancers (CRCs) and varied subsets of other cancers have somatic mutations leading to beta-catenin stabilization and increased beta-catenin/TCF transcriptional activity. Inhibition of stabilized beta-catenin in CRC cell lines arrests their growth and highlights the potential of this mechanism for novel cancer therapeutics. We have pursued efforts to develop small molecules that inhibit beta-catenin/TCF transcriptional activity. We used xanthothricin, a known beta-catenin/TCF antagonist of microbial origin, as a lead compound to synthesize related analogues with drug-like features such as low molecular weight and good metabolic stability. We studied a panel of six candidate Wnt/beta-catenin/Tcf-regulated genes and found that two of them (Axin2, Lgr5) were reproducibly activated (9-10 fold) in rat intestinal epithelial cells (IEC-6) following beta-catenin stabilization by Wnt-3a ligand treatment. Two previously reported beta-catenin/TCF antagonists (calphostin C, xanthothricin) and XAV939 (tankyrase antagonist) inhibited Wnt-activated genes in a dose-dependent fashion. We found that four of our compounds also potently inhibited Wnt-mediated activation in the panel of target genes. We investigated the mechanism of action for one of these (8c) and demonstrated these novel small molecules inhibit beta-catenin transcriptional activity by degrading beta-catenin via a proteasome-dependent, but GSK3 beta-, APC-, AXIN2- and beta TrCP-independent, pathway. The data indicate the compounds act at the level of beta-catenin to inhibit Wnt/beta-catenin/TCF function and highlight a robust strategy for assessing the activity of beta-catenin/TCF antagonists. (c) 2013 Elsevier Ltd. All rights reserved.
Investigation of 3-aryl-pyrimido[5,4-e][1,2,4]triazine-5,7-diones as small molecule antagonists of β-catenin/TCF transcription
作者:Jörg Zeller、Anjanette J. Turbiak、Ian A. Powelson、Surin Lee、Duxin Sun、H.D. Hollis Showalter、Eric R. Fearon
DOI:10.1016/j.bmcl.2013.08.111
日期:2013.11
Nearly all colorectal cancers (CRCs) and varied subsets of other cancers have somatic mutations leading to beta-catenin stabilization and increased beta-catenin/TCF transcriptional activity. Inhibition of stabilized beta-catenin in CRC cell lines arrests their growth and highlights the potential of this mechanism for novel cancer therapeutics. We have pursued efforts to develop small molecules that inhibit beta-catenin/TCF transcriptional activity. We used xanthothricin, a known beta-catenin/TCF antagonist of microbial origin, as a lead compound to synthesize related analogues with drug-like features such as low molecular weight and good metabolic stability. We studied a panel of six candidate Wnt/beta-catenin/Tcf-regulated genes and found that two of them (Axin2, Lgr5) were reproducibly activated (9-10 fold) in rat intestinal epithelial cells (IEC-6) following beta-catenin stabilization by Wnt-3a ligand treatment. Two previously reported beta-catenin/TCF antagonists (calphostin C, xanthothricin) and XAV939 (tankyrase antagonist) inhibited Wnt-activated genes in a dose-dependent fashion. We found that four of our compounds also potently inhibited Wnt-mediated activation in the panel of target genes. We investigated the mechanism of action for one of these (8c) and demonstrated these novel small molecules inhibit beta-catenin transcriptional activity by degrading beta-catenin via a proteasome-dependent, but GSK3 beta-, APC-, AXIN2- and beta TrCP-independent, pathway. The data indicate the compounds act at the level of beta-catenin to inhibit Wnt/beta-catenin/TCF function and highlight a robust strategy for assessing the activity of beta-catenin/TCF antagonists. (c) 2013 Elsevier Ltd. All rights reserved.