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.
A New Route to Substituted Pyrimido[5,4-e]-1,2,4-triazine-5,7(1H,6H)-diones and Facile Extension to 5,7(6H,8H) Isomers
作者:H. Showalter、Anjanette Turbiak
DOI:10.1055/s-0029-1217030
日期:2009.12
pyrimido[5,4-e]-1,2,4-triazine-5,7(1H,6H)-diones is outlined. The synthesis proceeds via pre-formed hydrazone intermediates, which are then condensed with an activated chlorouracil to build up the entire molecular framework, followed by a reductive ring closure to provide the parent series. The route has been extended to the isomeric pyrimido[5,4-e]-1,2,4-triazine-5,7(6H,8H)-dione class via the use of methylhydrazine
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.
A novel synthesis of N1-(substituted)-pyrimido[5,4-e]-1,2,4-triazine-5,7(1H,6H)-diones
作者:Anjanette J. Turbiak、H.D. Hollis Showalter
DOI:10.1016/j.tetlet.2009.02.084
日期:2009.4
A new synthesis of N1-(substituted)-pyrimido[5,4-e]-1,2,4-triazine-5,7(1H,6H)-diones, which are analogues of the natural product toxoflavin, is reported. Condensation of preformed alkyl or aryl hydrazones with 6-chloro-3-methyl-5-nitrouracil efficiently provides pyrimidotriazinediones in a three-step process that broadens the scope of R1 substituents.
N 1 -(取代)-嘧啶基[5,4- e ]-1,2,4-三嗪-5,7(1 H ,6 H ) -二酮的新合成,它们是天然产物毒素黄素的类似物,被报道。预先形成的烷基或芳基腙与 6-氯-3-甲基-5-硝基尿嘧啶的缩合可通过三步法有效地提供嘧啶并三嗪二酮,从而拓宽了 R 1取代基的范围。