Fused bi-heteroaryl substituted hydantoin compounds as TACE inhibitors.

We have identified a series of hydantoin-derived TNF-a converting enzyme (TACE) inhibitors containing a pendant fused bi-heteroaryl group, which demonstrate sub-nanomolar potency (Ki), excellent activity in human whole blood assay, and improved DMPK profiles over prior series.

Investigation the mechanism of the apoptosis induced by lactacystin in gastric cancer cells.

The study aims to investigate the relationship between nuclear factor (nuclear factor kappa B (NF-κB)) viability and lactacystin-mediated cell apoptosis in gastric cancer cells. Two gastric cancer cell lines (MKN28 and SGC7901) were treated with lactacystin-a proteasome inhibitor for 24 h. The cell viability, toxicity, and death were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. DNA binding viability of NF-κB and caspase-3 viability were analyzed by ELISA; the expression of p65 NF-κB nuclear protein was detected by immunocytochemistry and Western blot. Lactacystin reduced DNA binding viability of NF-κB (t = 3.0,P = 0.013) and the NF-κB viability (compared to the 5, 10 µmol/L MKN28 cell (p53 mutant) line, P < 0.001) and the expression of p65 NF-κB nuclear protein decreased parallelled to concentrations of lactacystin in MKN28 cell line, while without obvious effects on NF-κB viability in SGC7901 cell line (P = 0.381), while the viability of caspase-3 increased also along with the raising of lactacystin concentrations (compared to control, 5 µmol/L: SGC7901 cell line P = 0.029, MKN28 cell line P < 0.001; 10 µmol/L: SGC7901 cell line, P < 0.001, MKN28 cell line, P < 0.001). It was concluded that lactacystin had diversified killing effects on gastric cancer cells. The mechanism may be related to induce the apoptosis by downregulation of nuclear factor kappa B viability. There may be additional cell survival/death pathway in SGC7901 gastric cancer cells.

Discovery of novel spiro 1,3,4-thiadiazolines as potent, orally bioavailable and brain penetrant KSP inhibitors.

Kinesin spindle protein (KSP) is a mitotic kinesin that is expressed only in proliferating cells and plays a key role in spindle pole separation, formation of a bipolar mitotic spindle, as well as centrosome separation and maturation. Inhibition of KSP has the potential to provide anti-tumor activity while avoiding peripheral neuropathy associated with some microtubule-targeted drugs. Based on MK-0731 and related heterocyclic compounds targeting the KSP monastrol binding site, structurally constrained spiro-cyclic KSP inhibitors were designed. In particular, rapid evaluation and optimization of the novel spiro 1,3,4-thiadiazolines resulted in a series of potent KSP inhibitors demonstrating mechanism based activities in cells, including induction of the mitotic marker phospho-histone H3 and induction of monaster spindle formation. Further optimization of the pharmacokinetic (PK) properties afforded MK-8267 as a potent, orally bioavailable and brain penetrant KSP inhibitor which showed anti-tumor activity in preclinical xenograft models.

Intranasal immunization with live attenuated influenza vaccine plus chitosan as an adjuvant protects mice against homologous and heterologous virus challenge.

Our previous studies have proven the adjuvanticity of chitosan in mice when administered with inactivated and subunit influenza vaccine. In this study, we investigated the adjuvant effect of chitosan on the immunogenicity and protective efficacy of a live attenuated influenza vaccine. Mice were inoculated intranasally with live attenuated influenza vaccine plus chitosan and then challenged with a high, lethal dose of homologous or heterologous virus. Antibody responses, secretion of IFN-γ by spleen cells, body weight loss, survival rates, and residual lung virus titers were tested. The results demonstrated that live attenuated influenza vaccine with chitosan adjuvant not only protected mice completely against challenge with the homologous virus but also provided good cross-protection against a heterologous virus. In addition, chitosan as adjuvant could significantly increase the levels of antigen-specific antibodies and the population of IFN-γ-secreting T cells. These results reveal the potential of chitosan as a candidate adjuvant for use in a live attenuated influenza vaccine.

2-(2-Aminothiazol-4-yl)pyrrolidine-based tartrate diamides as potent, selective and orally bioavailable TACE inhibitors.

TNF-α converting enzyme (TACE) inhibitors are promising agents to treat inflammatory disorders and cancer. We have investigated novel tartrate diamide TACE inhibitors where the tartrate core binds to zinc in a unique tridentate fashion. Incorporating (R)-2-(2-N-alkylaminothiazol-4-yl)pyrrolidines into the left hand side amide of the tartrate scaffold led to the discovery of potent and selective TACE inhibitors, some of which exhibited good rat oral bioavailability.

Design, synthesis and SAR of thienopyridines as potent CHK1 inhibitors.

A novel series of CHK1 inhibitors based on thienopyridine template has been designed and synthesized. These inhibitors maintain critical hydrogen bonding with the hinge and conserved water in the ATP binding site. Several compounds show single digit nanomolar CHK1 activities. Compound 70 shows excellent enzymatic activity of 1 nM.

Structure and activity relationships of tartrate-based TACE inhibitors.

The syntheses and structure-activity relationships of the tartrate-based TACE inhibitors are discussed. The optimization of both the prime and non-prime sites led to compounds with picomolar activity. Several analogs demonstrated good rat pharmacokinetics.

Novel TNF-α converting enzyme (TACE) inhibitors as potential treatment for inflammatory diseases.

Our research on hydantoin based TNF-α converting enzyme (TACE) inhibitors has led to an acetylene containing series that demonstrates sub-nanomolar potency (K(i)) as well as excellent activity in human whole blood. These studies led to the discovery of highly potent TACE inhibitors with good DMPK profiles.

The discovery of novel tartrate-based TNF-alpha converting enzyme (TACE) inhibitors.

A novel series of TNF-alpha convertase (TACE) inhibitors which are non-hydroxamate have been discovered. These compounds are bis-amides of L-tartaric acid (tartrate) and coordinate to the active site zinc in a tridentate manner. They are selective for TACE over other MMP's. We report the first X-ray crystal structure for a tartrate-based TACE inhibitor.

Discovery and SAR of hydantoin TACE inhibitors.

We disclose inhibitors of TNF-alpha converting enzyme (TACE) designed around a hydantoin zinc binding moiety. Crystal structures of inhibitors bound to TACE revealed monodentate coordination of the hydantoin to the zinc. SAR, X-ray, and modeling designs are described. To our knowledge, these are the first reported X-ray structures of TACE with a hydantoin zinc ligand.

SCH 2047069, a novel oral kinesin spindle protein inhibitor, shows single-agent antitumor activity and enhances the efficacy of chemotherapeutics.

Kinesin spindle protein (KSP) is a mitotic kinesin required for the formation of the bipolar mitotic spindle, and inhibition of this motor protein results in mitotic arrest and cell death. KSP inhibitors show preclinical antitumor activity and are currently undergoing testing in clinical trials. These agents have been dosed intravenously using various dosing schedules. We sought to identify a KSP inhibitor that could be delivered orally and thus provide convenience of dosing as well as the ability to achieve more continuous exposure via the use of dose-dense administration. We discovered SCH 2047069, a potent KSP inhibitor with oral bioavailability across species and the ability to cross the blood-brain barrier. The compound induces mitotic arrest characterized by a monaster spindle and is associated with an increase in histone H3 and mitotic protein monoclonal 2 phosphorylation both in vitro and in vivo. SCH 2047069 showed antitumor activity in a variety of preclinical models as a single agent and in combination with paclitaxel, gemcitabine, or vincristine.