- Investigation of 3-aryl-pyrimido[5,4-e][1,2,4]triazine-5,7-diones as small molecule antagonists of β-catenin/TCF transcription
-
Nearly all colorectal cancers (CRCs) and varied subsets of other cancers have somatic mutations leading to β-catenin stabilization and increased β-catenin/TCF transcriptional activity. Inhibition of stabilized β-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 β-catenin/TCF transcriptional activity. We used xanthothricin, a known β-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/β-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 β-catenin stabilization by Wnt-3a ligand treatment. Two previously reported β-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 β-catenin transcriptional activity by degrading β-catenin via a proteasome-dependent, but GSK3β-, APC-, AXIN2- and βTrCP-independent, pathway. The data indicate the compounds act at the level of β-catenin to inhibit Wnt/β-catenin/TCF function and highlight a robust strategy for assessing the activity of β-catenin/TCF antagonists.
- Zeller, J?rg,Turbiak, Anjanette J.,Powelson, Ian A.,Lee, Surin,Sun, Duxin,Showalter, H.D. Hollis,Fearon, Eric R.
-
supporting information
p. 5814 - 5820
(2013/10/22)
-
- Synthesis, biological active molecular design, and molecular docking study of novel deazaflavin-cholestane hybrid compounds
-
Novel deazaflavin-cholestane hybrid compounds, 3′,8′-disubstituted-5′-deazacholest-2,4-dieno[2,3-g]pteridine-2′,4′(3′H,8′H)-diones, have been synthesized by condensation reaction between 6-(monosubstituted amino)-pyrimidin-2,4(1H,3H)-diones and 2-hydroxymethylenecholest-4-en-3-one in presence of p-toluenesulfonic acid monohydrate and diphenyl ether. The antitumor activities against human tumor cell lines (CCRF-HSB-2 and KB cells) have been investigated in vitro, and many of these compounds showed promising antitumor activities. Furthermore, molecular docking study using LigandFit within the software package Discovery Studio 1.7 was done for lead optimization of these compounds as potential PTK inhibitors. In general, all of the synthesized steroid-hybrid compounds showed good binding affinities into PTK (PDB code: 1t46).
- Shrestha, Ajaya R.,Shindo, Takashi,Ashida, Noriyuki,Nagamatsu, Tomohisa
-
body text
p. 8685 - 8696
(2009/04/11)
-
- ISOLATION OF NEW CHLORINATED REGIOISOMERS OF MONO N-SUBSTITUTED URACIL DERIVATIVES AND SYNTHESIS OF 3-SUBSTITUTED 8-PHENYLPYRIMIDO-1,2,4-TRIAZINE-5,7(6H,8H)-DIONES
-
A variety of fervenulin type products, 3-substituted 8-phenylpyrimido-1,2,4-triazine-5,7(6H,8H)-diones (18a-i), were synthesized by nitrosative or nitrative cyclization of the aldehyde hydrazones (17a-i) derived from 6-(1-methylhydrazino)-1-phenyluracil (16) with aliphatic as well as aromatic aldehydes.The compound (16) was prepared by the reaction of 6-chloro-1-phenyluracil (8) with methylhydrazine.In addition, not only the precursor of 16, 6-chloro-1-phenyluracil (8), but also other new chlorinated regioisomers of mono N-substituted pyrimidine (9) and uracil (14) were isolated and characterized by the reductive dechlorination of them.
- Nagamatsu, Tomohisa,Yamasaki, Hirofumi,Yoneda, Fumio
-
p. 1147 - 1164
(2007/10/02)
-