Curcuminoids Block TGF-b Sibnaling in HBC

Effects of curcuminoids on breast cancer cell secretion of the bone-resorptive peptide parathyroid hormone-related protein (PTHrP) and on lytic breast cancer bone metastasis were evaluated.

 

 

In vitro, transforming growth factor (TGF)-β-stimulated PTHrP secretion was inhibited by curcuminoids (IC₅₀ = 24 μM) in MDA-MB-231 human breast cancer cells independent of effects on cell growth inhibition.


Effects on TGF-β signaling revealed decreases in phospho-Smad2/3 and Ets-1 protein levels with no effect on p-38 MAPK-mediated TGF-β signaling.


 In vivo, mice were inoculated with MDA-MB-231 cells into the left cardiac ventricle and treated ip every other day with curcuminoids (25 or 50 mg/kg) for 21 days.


Osteolytic bone lesion area was reduced up to 51% (p < 0.01).


Consistent with specific effects on bone osteolysis, osteoclast number at the bone–tumor interface was reduced up to 53% (p < 0.05), while tumor area within bone was unaltered.


 In a separate study, tumor mass in orthotopic mammary xenografts was also unaltered by treatment.


These data suggest that curcuminoids prevent TGF-β induction of PTHrP and reduce osteolytic bone destruction by blockade of Smad signaling in breast cancer cells.

 

 

Cancer Drug Clinical Candidate Tipifarnib for Anti-Chagas Disease Drug Discovery

We previously reported that the cancer drug clinical candidate tipifarnib kills the causative agent of Chagas disease, Trypanosoma cruzi, by blocking ergosterol biosynthesis at the level of inhibition of lanosterol 14α-demethylase.


Tipifarnib is an inhibitor of human protein farnesyltransferase. We synthesized tipifarnib analogues that no longer bind to protein farnesyltransferase and display increased potency for killing parasites.


This was achieved in a structure-guided fashion by changing the substituents attached to the phenyl group at the 4-position of the quinoline ring of tipifarnib and by replacing the amino group by OMe.


Several compounds that kill Trypanosoma cruzi at subnanomolar concentrations and are devoid of protein farnesyltransferase inhibition were discovered. The compounds are shown to be advantageous over other lanosterol 14α-demethylase inhibitors in that they show only modest potency for inhibition of human cytochrome P450 (3A4).


Since tipifarnib displays high oral bioavailability and acceptable pharmacokinetic properties, the newly discovered tipifarnib analogues are ideal leads for the development of drugs to treat Chagas disease.


 

N-Heteroarylation of Chiral α-Aminoesters by Means of Palladium-Catalyzed Buchwald–Hartwig Reaction

N-Heteroaryl-α-amino acid derivatives are valuable pharmacological agents as peptidomimetics.

 

 

Classical S_NAr methods using acid catalysis and elevated temperatures could not be extended to various α-amino acids and fairly electrophilic heterocyclic partners.

 

 

Here, we report a mild and versatile method of N-heteroarylation of chiral α-aminoesters without racemization, involving Buchwald–Hartwig conditions.

 

 

It could be extended to various α-amino acids and azines.

 

This efficient N-heteroarylation leads to (i) a chemical library of putative peptidomimetics combining diverse azaheterocycles with the chiral α-aminoesters and their corresponding derivatives (amides, alcohols, etc.) and (ii) arginine derivatives designed as NPFF receptor ligands.

http://pubs.acs.org/doi/pdfplus/10.1021/jo4011427

Setileuton, a Potent and Selective 5-Lipoxygenase Inhibitor

Versatile One-Pot Route to 2-Quinoline-3-carboxamides

Novel Inhibitors of TGF Signaling

 

 

Annulated 1,4-Dihydropyridines Cardiomyogenic Compounds

as Novel Inhibitors of TGFβ Signaling

 

 

 

A medium-throughput murine embryonic stem cell (mESC)-based high-content screening of 17000 small molecules for cardiogenesis led to the identification of a b-annulated 1,4-dihydropyridine (1,4-DHP) that inhibited transforming growth factor β (TGFβ)/Smad signaling by clearing the type II TGFβ receptor from the cell surface.

 

 

Because this is an unprecedented mechanism of action, we explored the series’ structure–activity relationship (SAR) based on TGFβ inhibition, and evaluated SAR aspects for cell-surface clearance of TGFβ receptor II (TGFBR2) and for biological activity in mESCs.

 

 

We determined a pharmacophore and generated 1,4-DHPs with IC₅₀s for TGFβ inhibition in the nanomolar range (e.g., compound 28, 170 nM).

 

 

Stereochemical consequences of a chiral center at the 4-position was evaluated, revealing 10- to 15-fold more potent TGFβ inhibition for the (+)- than the (−) enantiomer.

 

 

This stereopreference was not observed for the low level inhibition against Activin A signaling and was reversed for effects on calcium handling in HL-1 cells.

 

 

 

 

http://pubs.acs.org/doi/abs/10.1021/jm301144g?prevSearch=TGF%25CE%25B2%2BInhibitor&searchHistoryKey=

 

 

 

 

 

Cyanine Dye N744 Inhibits Tau Fibrillization

Cyanine Dye N744 Inhibits Tau Fibrillization by Blocking Filament Extension:  Implications for the Treatment of Tauopathic Neurodegenerative Diseases

 

 

 

 

 

 

 

Orally Bioavailable, Brain Penetrant Kinase 3 Inhibitor for Parkinsons D

Orally Bioavailable, Brain Penetrant Inhibitor of Mixed Lineage Kinase 3

 

 

 

 

 

 

 

 

Inhibition of mixed lineage kinase 3 (MLK3) is a potential strategy for treatment of Parkinson’s disease and HIV-1 associated neurocognitive disorders (HAND), requiring an inhibitor that can achieve significant brain concentration levels.

 

 

 

We report here URMC-099 (1) an orally bioavailable (F = 41%), potent (IC₅₀ = 14 nM) MLK3 inhibitor with excellent brain exposure in mouse PK models and minimal interference with key human CYP450 enzymes or hERG channels.

 

 

 

The compound inhibits LPS-induced TNFα release in microglial cells, HIV-1 Tat-induced release of cytokines in human monocytes and up-regulation of phospho-JNK in Tat-injected brains of mice. Compound 1 likely functions in HAND preclinical models by inhibiting multiple kinase pathways, including MLK3 and LRRK2 (IC₅₀ = 11 nM). We compare the kinase specificity and BBB penetration of 1 with CEP-1347 (2). Compound 1 is well tolerated, with excellent in vivo activity in HAND models, and is under investigation for further development.

 

 

 

Compounds for the Treatment of Neurodegenerative Diseases

A series of indoles with Biaryl Appendage

are claimed as molecules that inhibit tau phosphorylation.
This approach to neurodegenerative disease is of interest because of the hypothesized role for tau in neuronal cell death.


Tau is an intracellular protein that stabilizes microtubules and helps regulate their function, for example in cell division.


Test compounds were studied for their ability to inhibit tau phosphorylation or inhibit α-synuclein in animals and in cell culture.

Fluorescence Probes for Protease and Glycosidase

We have synthesized and evaluated a series of hydroxymethyl rhodamine derivatives and found an intriguing difference of intramolecular spirocyclization behavior: the acetylated derivative of hydroxymethyl rhodamine green (Ac-HMRG) exists as a closed spirocyclic structure in aqueous solution at physiological pH, whereas HMRG itself takes an open nonspirocyclic structure. Ac-HMRG is colorless and nonfluorescent, whereas HMRG is strongly fluorescent.

 

 

 

On the basis of these findings, we have developed a general design strategy to obtain highly sensitive fluorescence probes for proteases and glycosidases, by replacing the acetyl group of Ac-HMRG with a substrate moiety of the target enzyme. Specific cleavage of the substrate moiety in the nonfluorescent probe by the target enzyme generates a strong fluorescence signal.

 

 

 

To confirm the validity and flexibility of our strategy, we designed and synthesized fluorescence probes for leucine aminopeptidase (Leu-HMRG), fibroblast activation protein (Ac-GlyPro-HMRG), and β-galactosidase (βGal-HMRG).

 

 

All of these probes were almost nonfluorescent due to the formation of spirocyclic structure, but were converted efficiently to highly fluorescent HMRG by the target enzymes.

 

 

We confirmed that the probes can be used in living cells. These probes offer great practical advantages, including high sensitivity and rapid response (due to regulation of fluorescence at a single reactive site), as well as resistance to photobleaching, and are expected to be useful for a range of biological and pathological investigations.

 

 

 

Adventures in Kinase Inhibitor Design and Optimization

Through the Looking Glass: Adventures in Kinase Inhibitor Design and Optimization

 

Robert D. Clark *

Department of Life Sciences, Simulations Plus, Inc., 42505 10th Street West, Lancaster, California 93534, United States

J. Med. Chem., 2013, 56 (5), pp 1796–1798

DOI: 10.1021/jm400243u

Abstract

Developing a viable new drug candidate is difficult.

Developing one that is a small molecule kinase inhibitor that binds competitively with respect to ATP with superb selectivity is even more difficult, which makes the design and optimization work described by Jimenez et al. (J. Med. Chem., DOI: 10.1021/jm301465a) particularly remarkable.

 

 

 They took a lead from a high-throughput screen against protein kinase C θ (PKCθ) through a series of optimization steps, culminating in the demonstration of in vivo activity in mice. Having identified and improved the hinge-binding “warhead” at one end of their lead molecule, they proceeded to use structure-based design tools to guide modification of the other end to enhance selectivity over a closely related isoform of the kinase. With that accomplished, they used a series of protection and deprotection maneuvers to modify the central portion of the series scaffold to further enhance potency against the target while also improving pharmacokinetic properties.

 

 

The project was a success at the preclinical level: oral administration of the ultimate analogue obtained was effective at suppressing interleukin-2 induction in mice.

 

 

 

 

Ortho Directed Metallation for Indole Synthesis

6-Azaindoles from aminopyridines

Epigenetic Regulator I-BET762

Benzodiazepine & Benzoxazepine Inhibitors: 2013 JMC

Antiinflammatory Activity of 8-Substituted-4-anilino-6-aminoquinoline-3-carbonitriles

Using molecular modeling and crystallographic data of the EGFR kinase domain with and without an EGFR kinase-specific 4-anilinoquinazoline inhibitor (erlotinib, Tarceva), we hypothesized that we could diminish the inhibition of EGFR kinase by substitution at the C-8 position of our 4-anilino-6-aminoquinoline-3-carbonitrile leads.


The 8-substituted-4-anilino-6-aminoquinoline-3-carbonitriles were prepared from the appropriate 2-substituted 4-nitroanilines. Modifications to the C-6 and C-8 positions led to the identification of compounds with increased inhibition of TNF-α release from LPS-stimulated rat and human blood, and these analogues were also highly selective for Tpl2 kinase over EGFR kinase.



Further structure−activity based modifications led to the identification of 8-bromo-4-(3-chloro-4-fluorophenylamino)-6-[(1-methyl-1H-imidazol-4-yl)methylamino]quinoline-3-carbonitrile, which demonstrated in vitro as well as in vivo efficacy in inhibition of LPS-induced TNF-α production.

Selective DDR1 Receptor Tyrosine Kinase Inhibitor

We identified a mutation in the hinge region of DDR1, G707A, that confers >20-fold resistance to the ability of DDR1-IN-1 to inhibit DDR1 autophosphorylation and can be used to establish what pharmacology is DDR1-dependent.


A combinatorial screen of DDR1-IN-1 with a library of annotated kinase inhibitors revealed that inhibitors of PI3K and mTOR such as GSK2126458 potentiate the antiproliferative activity of DDR1-IN-1 in colorectal cancer cell lines.



DDR1-IN-1 provides a useful pharmacological probe for DDR1-dependent signal transduction.

Dinaciclib Interacts with the Acetyl-Lysine Recognition Site of Bromodomains

 

https://en.wikipedia.org/wiki/Dinaciclib

Dinaciclib is a potent inhibitor of cyclin-dependent kinases (CDKs), which recently advanced to Phase III clinical trials for the treatment of leukemia.



We determined the crystal structure of dinaciclib in complex with CDK2 at 1.7 Å resolution, revealing an elaborate network of binding interactions in the ATP site, which explains the extraordinary potency and selectivity of this inhibitor.


Remarkably, dinaciclib also interacted with the acetyl-lysine recognition site of the bromodomain testis-specific protein BRDT, a member of the BET family of bromodomains.


The binding mode of dinaciclib to BRDT at 2.0 Å resolution suggests that general kinase inhibitors (“hinge binders”) possess a previously unrecognized potential to act as protein–protein inhibitors of bromodomains.


The findings may provide a new structural framework for the design of next-generation bromodomain inhibitors using the vast chemical space of kinase inhibitors.

Tau Aggregation Inhibitors

Agents capable of preventing the misfolding and sequestration of the microtubule-stabilizing protein tau into insoluble fibrillar aggregates hold considerable promise for the prevention and/or treatment of neurodegenerative tauopathies such as Alzheimer’s disease.

 

 

Because tauopathies are characterized by amyloidosis that is restricted to the central nervous system (CNS), plausible candidate compounds for in vivo evaluation must both prevent tau fibrillization and achieve significant brain levels.

 

 

Recently, we reported the discovery of the aminothienopyridazine (ATPZ) class of tau aggregation inhibitors

 

and now describe a series of new analogues that are both effective inhibitors of tau fibrillization and display significant brain-to-plasma exposure ratios after administration to mice.

 

 

 

Further, two of the most promising examples, 15 and 16, were found to reach significant brain exposure levels following oral administration. Taken together, these results suggest that examples from the ATPZ class hold promise as candidates for in vivo efficacy studies in animal models of neurodegenerative tauopathies.

Tau Complex Inhibition by Prototype Inhibitors

Kinetic Studies of Cdk5/p25 Kinase:

Phosphorylation of Tau and Complex Inhibition by Two Prototype Inhibitors








These studies served as a necessary kinetic backdrop for investigations of the mechanism of inhibition by prototype inhibitors :

N4-(6-aminopyrimidin-4-yl)-sulfanilamide (APS) and 1-(5-cyclobutyl-thiazol-2-yl)-3-isoquinolin-5-yl-urea (CTIU).


We found that the cdk5/p25-catalyzed phosphorylation of tau follows a rapid equilibrium, random kinetic mechanism, as evidenced by initial velocity analysis indicating sequential addition of tau and ATP, and studies of the mechanism of inhibition by substrate analogue AMP, product ADP, and analogues of peptide substrate H1P. Identical mechanistic conclusions were drawn when H1P was the phosphoryl acceptor.



Subsequent studies of inhibition by APS and CTIU revealed that
both compounds can bind to all four steady-state forms of the enzyme,
to form the complexes E:I, E:I:tau, E:I:ATP, and E:I:tau:ATP.



These results contrast with reported claims that APS and CTIU are competitive inhibitors of the binding of ATP.

Type II Kinase Inhibitors

 

 

 

A number of well-known type II inhibitors (ATP-noncompetitive) that bind kinases in their DFG-out conformation were tested against wild-type LRRK2 and the most common Parkinson’s disease-linked mutation, G2019S.

 

 

We found that traditional type II inhibitors exhibit surprising variability in their inhibition mechanism between the wild type (WT) and the G2019S mutant of LRRK2.

 

 

The type II kinase inhibitors were found to work in an ATP-competitive fashion against the G2019S mutant, whereas they appear to follow the expected noncompetitive mechanism against WT.

 

 

 

Because the G2019S mutation lies in the DXG motif (DYG in LRRK2 but DFG in most other kinases) of the activation loop, we explored the structural consequence of the mutation on loop dynamics using an enhanced sampling method called metadynamics.

 

 

 

The simulations suggest that the G2019S mutation stabilizes the DYG-in state of LRRK2 through a series of hydrogen bonds, leading to an increase in the conformational barrier between the active and inactive forms of the enzyme and a relative stabilization of the active form.

 

 

The conformational bias toward the active form of LRRK2 mutants has two primary consequences. (1)

 

 

 

The mutant enzyme becomes hyperactive, a known contributor to the Parkinsonian phenotype, as a consequence of being “locked” into the activated state, and (2) the mutation creates an unusual allosteric pocket that can bind type II inhibitors but in an ATP-competitive fashion.

 

 

 

Our results thus suggest that developing type II inhibitors, which are generally considered superior to type I inhibitors because of desirable selectivity profiles, might be especially challenging for the G2019S LRRK2 mutant.

 

 

 

P450 Oxidation Site: A RS Prediction

がん幹細胞療法の入口

◆　癌細胞の　親玉　をたたく新薬（旧薬）：

スフファサラジン

慶応佐谷先生のグループが行っている癌化学療法のねらいは、

がんの親玉（癌幹細胞）を　既存の薬をつかってやっつけるという

古い薬による　新しい　癌幹細胞療法　の開発だ。

 

 

本日1日の日経朝刊

または先日の　ニュースステーションでも

取り上げられた。

 

古い薬（既存薬）の方が、開発期間が短縮できること、

安全性が　ある程度保障されている点が　大きなメリットであり、

従って、薬の価格も　低く抑えられる　

理想の創薬＝理想の転薬＝リポジション創薬

だ。