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Neurabin I is a brain-specific actin-binding protein. Here we show that neurabin I binds protein phosphatase 1 (PP1) and inhibits PP1 activity. Neurabin I interacted with PP1alpha in an overlay assay, in yeast two-hybrid interaction analysis, and in coprecipitation and co-immunoprecipitation experiments. Neurabin I also copurified with both the alpha and gamma isoforms of PP1. A glutathione S-transferase (GST)-neurabin I fusion protein (residues 318-661) containing the putative PP1 binding domain (residues 456-460) inhibited PP1 activity (K(i) = 2.7 +/- 1.2 nM). This fusion protein was also rapidly phosphorylated in vitro by PKA (K(m) = 6 microM) to a stoichiomtry of 1 mol/mol. The phosphorylated residue was identified as serine 461 by HPLC-MS analysis of a tryptic digest. Phosphorylation of GST-neurabin I (residues 318-661) by PKA significantly reduced its binding to PP1 by overlay and by glutathione-Sepharose coprecipitation assays. A 35-fold decrease in inhibitory potency was also observed using a S461E mutant, which mimics phosphorylation of S461. These findings identify a signaling mechanism involving the regulation of PP1 activity and localization mediated by the cAMP pathway.

Summary A series of ( E )-3-(4-hydroxy-5-methoxyindole-7-yl)-2-methylpropenoic acids was prepared and the inhibitory activities of its members on IL-1 generation were evaluated in an in vivo system using the rat carboxymethyl cellulose-lipopolysaccharide (CMC-LPS) air-pouch model. Many compounds in this new series were found to be inhibitors of IL-1 generation. Structure-activity relationships indicated that a methyl substituent at the 1- and 3-positions on the indole ring are important for activity and that a 3,4,5-trimethoxy-substituted 2-phenyl group on the indole ring is suitable to give compounds exhibiting inhibition after oral administration. Among the compounds evaluated, ( E )-3-[1,3-dimethyl-4-hydroxy-5-methoxy-2-(3,4,5-trimethoxyphenyl)indole-7-yl]-2-methylpropenoic acid ( 15m ), which inhibited IL-1 generation by human monocytes stimulated with various reagents such as LPS, opsonized zymosan and immune complexes, showed inhibitory activity in the rat CMC-LPS model after oral administration.

c-Met is the cellular receptor for hepatocyte growth factor (HGF) and is known to be dysregulated in various types of human cancers. Activation of the HGF/c-Met pathway causes tumor progression, invasion, and metastasis. Vascular endothelial growth factor (VEGF) is also known as a key molecule in tumor progression through the induction of tumor angiogenesis. Because of their key roles in tumor progression, these pathways provide attractive targets for therapeutic intervention. We have generated a novel, orally active, small molecule compound, E7050, which inhibits both c-Met and vascular endothelial growth factor receptor (VEGFR)-2. In vitro studies indicate that E7050 potently inhibits phosphorylation of both c-Met and VEGFR-2. E7050 also potently represses the growth of both c-met amplified tumor cells and endothelial cells stimulated with either HGF or VEGF. In vivo studies using E7050 showed inhibition of the phosphorylation of c-Met and VEGFR-2 in tumors, and strong inhibition of tumor growth and tumor angiogenesis in xenograft models. Treatment of some tumor lines containing c-met amplifications with high doses of E7050 (50-200 mg/kg) induced tumor regression and disappearance. In a peritoneal dissemination model, E7050 showed an antitumor effect against peritoneal tumors as well as a significant prolongation of lifespan in treated mice. Our results indicate that E7050 is a potent inhibitor of c-Met and VEGFR-2 and has therapeutic potential for the treatment of cancer.

Background Lenvatinib is an oral inhibitor of multiple receptor tyrosine kinases (RTKs) targeting vascular endothelial growth factor receptor (VEGFR1-3), fibroblast growth factor receptor (FGFR1-4), platelet growth factor receptor α (PDGFR α), RET and KIT. Antiangiogenesis activity of lenvatinib in VEGF- and FGF-driven angiogenesis models in both in vitro and in vivo was determined. Roles of tumor vasculature (microvessel density (MVD) and pericyte coverage) as biomarkers for lenvatinib were also examined in this study. Method We evaluated antiangiogenesis activity of lenvatinib against VEGF- and FGF-driven proliferation and tube formation of HUVECs in vitro. Effects of lenvatinib on in vivo angiogenesis, which was enhanced by overexpressed VEGF or FGF in human pancreatic cancer KP-1 cells, were examined in the mouse dorsal air sac assay. We determined antitumor activity of lenvatinib in a broad panel of human tumor xenograft models to test if vascular score, which consisted of high MVD and low pericyte coverage, was associated with sensitivity to lenvatinib treatment. Vascular score was also analyzed using human tumor specimens with 18 different types of human primary tumors. Result Lenvatinib inhibited VEGF- and FGF-driven proliferation and tube formation of HUVECs in vitro. In vivo angiogenesis induced by overexpressed VEGF (KP-1/VEGF transfectants) or FGF (KP-1/FGF transfectants) was significantly suppressed with oral treatments of lenvatinib. Lenvatinib showed significant antitumor activity in KP-1/VEGF and five 5 of 7 different types of human tumor xenograft models at between 1 to 100 mg/kg. We divided 19 human tumor xenograft models into lenvatinib-sensitive (tumor-shrinkage) and relatively resistant (slow-growth) subgroups based on sensitivity to lenvatinib treatments at 100 mg/kg. IHC analysis showed that vascular score was significantly higher in sensitive subgroup than relatively resistant subgroup (p

Eribulin mesylate (eribulin), a novel microtubule-targeted inhibitor, was approved ‘inoperable or recurrent breast cancer’ on April 2011 in Japan. In therapeutic system, trastuzumab is used for patients with HER2-positive breast cancer but the safety of combination of eribulin with trastuzumab is not established. And so, we conducted the clinical phase I study of eribulin in combination with trastuzumab in patients with HER2-positive breast cancer to evaluate dose limiting toxicity (DLT), and investigate tolerability and safety. Six patients with prior chemotherapy including trastuzumab and taxanes for advanced or metastatic breast cancer were evaluated in DLT evaluation periods (for 21 or 28 days after drug administration). Eribulin (1.4 mg/m2) was administered as an IV bolus on days 1 and 8 every 3-week cycle, which is approved dosage and schedule, and trastuzumab was administered as an IV infusion weekly (method A). As a result, no adverse events corresponding to DLT were observed, and the common adverse events were neutropenia and leukopenia. On day 15 after drug administration, one of six patients showed the slight decrease in left ventricular ejection fraction, but it was recovered on day 22. And thus, the combination of eribulin with trastuzumab was tolerable in DLT evaluation periods, and the safety profile in this study was similar to that in the past clinical studies of eribulin monotherapy. On the other hand, since the acute cardiac failure was observed, it was thought that the assessment of cardiac function in the combination of eribulin with trastuzumab should be carried out carefully.

Synthesis of prostaglandin A2 (PGA2) by means of a route involving enzymatic reactions is described. Enantioselective reduction and hydrolysis of trans-3, 4-bis(methoxycarbonyl)cyclopentanone (1) were examined using yeasts or enzymes, and it was found that (+)- and (-)-1 are easily obtained by an enzymatic procedure. Compound (+)-1 was converted to the Corey intermediate for PGA2 via the regioselective hydrolysis of the (+)-diacetate (8) with porcine pancreatic lipase. This synthesis based on the enzymatic approach was proved to be useful for the synthesis of both PGA and PGE from (-)-1.

SummaryEribulin mesylate (Halaven®) is a novel inhibitor of microtubule dynamics that has demonstrated a survival benefit in patients with locally recurrent or metastatic breast cancer who previously received at least two chemotherapeutic regimens including an anthracycline and a taxane. Although trastuzumab is indicated for patients with human epidermal growth factor receptor 2 positive (HER2+) breast cancer, a phase 1 study to evaluate tolerability/safety of eribulin mesylate with trastuzumab has not been conducted. Therefore, a study of eribulin mesylate in combination with trastuzumab was conducted to evaluate dose limiting toxicity (DLT), tolerability/safety, pharmacokinetics (PK), and efficacy and to estimate the recommended dose in Japanese patients with advanced or recurrent HER2+ breast cancer. Eribulin mesylate (1.4 mg/m2) was administered on days 1 and 8 of every 3 week cycle. Trastuzumab was administered with a 4 mg/kg loading dose followed by 2 mg/kg weekly doses or with an 8 mg/kg loading dose followed by 6 mg/kg tri-weekly doses. A total of 12 patients (six for each regimen) received eribulin mesylate and trastuzumab. No DLT was observed and the recommended dose of eribulin mesylate in combination with trastuzumab was estimated as 1.4 mg/m2. Common adverse events were neutropenia, leukopenia, anaemia and alopecia. This combination therapy was well tolerated and the neutropenia observed was manageable. No PK drug-drug interaction between eribulin and trastuzumab was observed. Since a transient ejection fraction decreased was observed in two patients, cardiac function should be routinely assessed in patients receiving the combination therapy of eribulin mesylate with trastuzumab (ClinicalTrials.gov Identifier: NCT01432886).

Synthesis of prostaglandin A2 (PGA2) by means of a route involving enzymatic reactions is described. Enantioselective reduction and hydrolysis of trans-3, 4-bis(methoxycarbonyl)cyclopentanone (1) were examined using yeasts or enzymes, and it was found that (+)- and (-)-1 are easily obtained by an enzymatic procedure. Compound (+)-1 was converted to the Corey intermediate for PGA2 via the regioselective hydrolysis of the (+)-diacetate (8) with porcine pancreatic lipase. This synthesis based on the enzymatic approach was proved to be useful for the synthesis of both PGA and PGE from (-)-1.