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.
Microwave-assisted synthesis of 3-aryl-pyrimido[5,4-e][1,2,4]triazine-5,7(1H,6H)-dione libraries: derivatives of toxoflavin
作者:Nick Todorovic、Andrew Giacomelli、John A. Hassell、Christopher S. Frampton、Alfredo Capretta
DOI:10.1016/j.tetlet.2010.09.044
日期:2010.11
The parallel synthesis of a library of toxoflavin derivatives is described. The microwave-assisted approach involves the de novo generation of the heterocyclic scaffold and allows for facile introduction of a variety of fragments.
The Facile Synthesis of 6-Azapurines by Transformation of Toxoflavins (7-Azapteridines)
作者:Tomohisa Nagamatsu、Jun Ma、Fumio Yoneda
DOI:10.3987/com-08-s(f)111
日期:——
- This paper describes a reliable and facile synthesis of 6-azapurines (1,5-dimethyl-1H-imidazo[4,5-e][1,2,4]triazin-6(5H)-ones) by treatment of toxoflavins (7-azapteridines) with 10% aqueous sodium hydroxide at 5-25 °C along with a benzilic acid type rearrangement, followed by decarboxylation and oxidation by air. Furthermore, heating the 6-azapurines in 10% ethanolic sodium hydroxides afforded the
Toxoflavins and Deazaflavins as the First Reported Selective Small Molecule Inhibitors of Tyrosyl-DNA Phosphodiesterase II
作者:Ali Raoof、Paul Depledge、Niall M. Hamilton、Nicola S. Hamilton、James R. Hitchin、Gemma V. Hopkins、Allan M. Jordan、Laura A. Maguire、Alison E. McGonagle、Daniel P. Mould、Mathew Rushbrooke、Helen F. Small、Kate M. Smith、Graeme J. Thomson、Fabrice Turlais、Ian D. Waddell、Bohdan Waszkowycz、Amanda J. Watson、Donald J. Ogilvie
DOI:10.1021/jm400568p
日期:2013.8.22
The recently discovered enzyme tyrosyl-DNA phosphodiesterase 2 (TDP2) has been implicated in the topoisomerase-mediated repair of DNA damage. In the clinical setting, it has been hypothesized that TDP2 may mediate drug resistance to topoisomerase II (topo II) inhibition by etoposide. Therefore, selective pharmacological inhibition of TDP2 is proposed as a novel approach to overcome intrinsic or acquired resistance to topo II-targeted drug therapy. Following a high-throughput screening (HTS) campaign, toxoflavins and deazaflavins were identified as the first reported sub-micromolar and selective inhibitors of this enzyme. Toxoflavin derivatives appeared to exhibit a clear structure-activity relationship (SAP.) for TDP2 enzymatic inhibition. However, we observed a key redox liability of this series, and this, alongside early in vitro drug metabolism and pharmacokinetics (DMPK) issues, precluded further exploration. The deazaflavins were developed from a singleton HTS hit. This series showed distinct SAR and did not display redox activity; however low cell permeability proved to be a challenge.
Pyrimidotriazinediones and Pyrimidopyrimidinediones and Methods of Using the Same
申请人:Showalter H.D. H.
公开号:US20110166144A1
公开(公告)日:2011-07-07
The present disclosure is directed to pyrimidotriazinediones and pyrimidopyrimidinediones having a formula (I), (II), or (III), or a mixture or pharmaceutically acceptable salt or hydrate thereof, and to methods of treating cancer comprising administering the same.
COMPOUNDS AND METHODS FOR TREATING TUBERCULOSIS INFECTION
申请人:Wong Chi-Huey
公开号:US20130158037A1
公开(公告)日:2013-06-20
The present invention provides compounds which are potent inhibitors against Lpd activity, PDH activity, and/or the growth of
tubercle bacillus
, and thus are useful in the treatment of tuberculosis infection and associated conditions. The present invention is further directed to in vitro- and in vzivo-based methods of inhibiting Lpd and/or PDH activity. In certain embodiments, these methods are useful in inhibiting Lpd and/or PDH activity key to a pathogen's survival.