Characterization of the cellular and antitumor effects of MPI-0479605, a small-molecule inhibitor of the mitotic kinase Mps1.

Mps1 is a dual specificity protein kinase that is essential for the bipolar attachment of chromosomes to the mitotic spindle and for maintaining the spindle assembly checkpoint until all chromosomes are properly attached. Mps1 is expressed at high levels during mitosis and is abundantly expressed in cancer cells. Disruption of Mps1 function induces aneuploidy and cell death.

Discovery and SAR of methylated tetrahydropyranyl derivatives as inhibitors of isoprenylcysteine carboxyl methyltransferase (ICMT).

A series of tetrahydropyranyl (THP) derivatives has been developed as potent inhibitors of isoprenylcysteine carboxyl methyltransferase (ICMT) for use as anticancer agents. Structural modification of the submicromolar hit compound 3 led to the potent 3-methoxy substituted analogue 27. Further SAR development around the THP ring resulted in an additional 10-fold increase in potency, exemplified by analogue 75 with an IC(50) of 1.

Oxindole derivatives as inhibitors of TAK1 kinase.

Several series of oxindole analogues were synthesized and screened for inhibitory activity against transforming growth factor-β-activating kinase 1 (TAK1). Modifications around several regions of the lead molecules were made, with a distal hydroxyl group in the D region being critical for activity. The most potent compound 10 shows an IC(50) of 8.

Analogues of 4-[(7-Bromo-2-methyl-4-oxo-3H-quinazolin-6-yl)methylprop-2-ynylamino]-N-(3-pyridylmethyl)benzamide (CB-30865) as potent inhibitors of nicotinamide phosphoribosyltransferase (Nampt).

We have shown previously that the target of the potent cytotoxic agent 4-[(7-bromo-2-methyl-4-oxo-3H-quinazolin-6-yl)methyl-prop-2-ynylamino]-N-(3-pyridylmethyl)benzamide (CB38065, 1) is nicotinamide phosphoribosyltransferase (Nampt). With its cellular target known we sought to optimize the biochemical and cellular Nampt activity of 1 as well as its cytotoxicity. It was found that a 3-pyridylmethylamide substituent in the A region was critical to cellular Nampt activity and cytotoxicity, although other aromatic substitution did yield compounds with submicromolar enzymatic inhibition.

Chemical proteomics identifies Nampt as the target of CB30865, an orphan cytotoxic compound.

Drug discovery based on cellular phenotypes is impeded by the challenge of identifying the molecular target. To alleviate this problem, we developed a chemical proteomic process to identify cellular proteins that bind to small molecules. CB30865 is a potent (subnanomolar) and selective cytotoxic compound of previously unknown mechanism of action.

2-Anilino-4-aryl-1,3-thiazole inhibitors of valosin-containing protein (VCP or p97).

Valosin-containing protein (VCP; also known as p97) is a member of the AAA ATPase family with a central role in the ubiquitin-degradation of misfolded proteins. VCP also exhibits antiapoptotic function and metastasis via activation of nuclear factor kappa-B signaling pathway. We have discovered that 2-anilino-4-aryl-1,3-thiazoles are potent drug-like inhibitors of this enzyme.

Discovery of N-(4-methoxyphenyl)-N,2-dimethylquinazolin-4-amine, a potent apoptosis inducer and efficacious anticancer agent with high blood brain barrier penetration.

As a continuation of our structure-activity relationship (SAR) studies on 4-anilinoquinazolines as potent apoptosis inducers and to identify anticancer development candidates, we explored the replacement of the 2-Cl group in our lead compound 2-chloro-N-(4-methoxyphenyl)-N-methylquinazolin-4-amine (6b, EP128265, MPI-0441138) by other functional groups. This SAR study and lead optimization resulted in the identification of N-(4-methoxyphenyl)-N,2-dimethylquinazolin-4-amine (6h, EP128495, MPC-6827) as an anticancer clinical candidate. Compound 6h was found to be a potent apoptosis inducer with EC(50) of 2 nM in our cell-based apoptosis induction assay.

Discovery of 2-chloro-N-(4-methoxyphenyl)-N-methylquinazolin-4-amine (EP128265, MPI-0441138) as a potent inducer of apoptosis with high in vivo activity.

Using a live cell, high-throughput caspase-3 activator assay, we have identified a novel series of 4-anilinoquinazolines as inducers of apoptosis. In this report, we discuss the discovery of 2-chloro-N-(4-methoxyphenyl)-N-methylquinazolin-4-amine, compound 2b (EP128265, MPI-0441138) as a highly active inducer of apoptosis (EC50 for caspase activation of 2 nM) and as a potent inhibitor of cell proliferation (GI50 of 2 nM) in T47D cells. Compound 2b inhibited tubulin polymerization, was effective in cells overexpressing ABC transporter Pgp-1, and was efficacious in the MX-1 human breast and PC-3 prostate cancer mouse models.

Protease-activated receptor 2, dipeptidyl peptidase I, and proteases mediate Clostridium difficile toxin A enteritis.

Background & Aims: We studied the role of protease-activated receptor 2 (PAR(2)) and its activating enzymes, trypsins and tryptase, in Clostridium difficile toxin A (TxA)-induced enteritis.

Methods: We injected TxA into ileal loops in PAR(2) or dipeptidyl peptidase I (DPPI) knockout mice or in wild-type mice pretreated with tryptase inhibitors (FUT-175 or MPI-0442352) or soybean trypsin inhibitor. We examined the effect of TxA on expression and activity of PAR(2) and trypsin IV messenger RNA in the ileum and cultured colonocytes.

The discovery of fluoropyridine-based inhibitors of the factor VIIa/TF complex--Part 2.

The activated factor VII/tissue factor complex (FVIIa/TF) is known to play a key role in the formation of blood clots. Inhibition of this complex may lead to new antithrombotic drugs. A fluoropyridine-based series of FVIIa/TF inhibitors was discovered which utilized a diisopropylamino group for binding in the S2 and S3 binding pockets of the active site of the enzyme complex.

The discovery of fluoropyridine-based inhibitors of the Factor VIIa/TF complex.

The activated Factor VII/tissue factor complex (FVIIa/TF) plays a key role in the formation of blood clots. Inhibition of this complex may lead to new antithrombotic drugs. An X-ray crystal structure of a fluoropyridine-based FVIIa/TF inhibitor bound in the active site of the enzyme complex suggested that incorporation of substitution at the 5-position of the hydroxybenzoic acid side chain could lead to the formation of more potent inhibitors through interactions with the S1'/S2' pocket.

Design, synthesis, and biological activity of potent and selective inhibitors of blood coagulation factor Xa.

Factor Xa (FXa) has materialized as a key enzyme for the intervention of the blood coagulation cascade and for the development of new antithrombotic agents. FXa is the lone enzyme responsible for the production of thrombin and therefore is an attractive target for the control of thrombus formation. We have designed and synthesized a unique series of quinoxalinone FXa inhibitors.

Platelet-rich plasma application in sinus graft surgery: Part I--Background and processing techniques.

The uses of cytokine growth factors in soft tissue applications has been reported on. The scientific background and various processing techniques to prepare the autologous materials are reviewed here. An ongoing research project to study grafting of the maxillary sinus for bone regeneration and implant site preparation with the growth factor Platelet Rich Plasma is outlined.