Total synthesis of (+)-A83586C, (+)-kettapeptin and (+)-azinothricin: powerful new inhibitors of beta-catenin/TCF4-and E2F-mediated gene transcription

Herein we describe our asymmetric total syntheses of (+)-A83586C, (+)-kettapeptin and (+)-azinothricin. We also demonstrate that molecules of this class powerfully inhibit beta-catenin/TCF4- and E2F-mediated gene transcription within malignant human colon cancer cells at low drug concentrations.

Development of an immunobiosensor assay for the beta-adrenergic compound zilpaterol

A surface plasmon resonance biosensor method was developed to measure zilpaterol residues in sheep urine. A CM-5 sensor chip previously reacted with ethylenediamine to produce an aminoethyl group was coupled with 4-carboxybutyl zilpaterol activated using EDC/NHS. Five polyclonal and four monoclonal antibodies were screened for their suitability to detect low levels of zilpaterol using the biosensor technology. Total binding was greater for polyclonal than monoclonal antibodies, but a less diluted antibody solution was required for polyclonal antibodies. A fixed antibody concentration and various concentrations of zilpaterol were injected to obtain a standard curve for each antibody to allow for B-0 and IC50 determination. The stability of the assay was assessed by the consistency of B0 in repeated experiments extending at least six hours. A measure of non-specific binding allowed the assessment of the specificity of the antibody-immobilized ligand interaction. The effect of varying concentrations of urine on B-0 and IC50 was evaluated to assess the degree of

In vitro testing of Advanced JAX (TM) Bone Void Filler System: species differences in the response of bone marrow stromal cells to beta tri-calcium phosphate and carboxymethylcellulose gel

The Advanced JAX (TM) Bone Void Filler System (AJBVFS) is a novel bone graft material manufactured by Smith and Nephew Orthopaedics Ltd. and comprises beta tri-calcium phosphate granules with carboxymethylcellulose (CMC) gel as a handling agent. This study investigated the potential, in vitro, of the AJBVFS to function as a delivery system for cell therapy to enhance healing of bone defects. The attachment of rabbit bone marrow stromal cells (rbBMSCs), human BMSCs (hBMSCs) and human bone-derived cells (hBDCs) to JAX (TM) granules and the effect of CMC gel on cell proliferation and differentiation were investigated. There were slight species differences in the number and morphology of cells attached on the JAX (TM) granules with less rbBMSC attachment than human. All cells tolerated the presence of CMC gel and a reduction in cell number was only seen after longer exposure to higher gel concentrations. Low concentrations of CMC gel enhanced proliferation, alkaline phosphatase (ALP) expression and ALP activity in human cells but had no effect on rbBMSC. This study suggests that AJBVFS is an appropriate scaffold for the delivery of osteogenic cells and the addition of CMC gel as a handling agent promotes osteogenic proliferation and differentiation and is therefore likely to encourage bone healing.

Bone growth into a ceramic-filled defect around an implant - The response to transforming growth factor beta 1

Synthetic bone substitutes provide an alternative to autograft but do not give equivalent clinical results. Their performance may be enhanced by adding osteogenic growth factors. In this study, TGFbeta1 was absorbed on to a carrier of 0 tricalcium phosphate and Gelfoam(R) and used to fill a defect around a tibial implant in a rat model of revision arthoplasty.

Reaction of tetracyanoethylene with alpha,beta-unsaturated ketones

Synthesis and Chemistry of simple tetracyanoalkanes is well studied. We performed tetracyanoethylation of unsaturated ketones with an active double bond in alpha-position. The reaction of tetracyanoethylene with alpha,beta-unsaturated ketones may result in four probable products depending on the character of substituents.

RUNX3 attenuates beta-catenin/T cell factors in intestinal tumorigenesis

In intestinal epithelial cells, inactivation of APC, a key regulator of the Wnt pathway, activates beta-catenin to initiate tumorigenesis. However, other alterations may be involved in intestinal tumorigenesis. Here we found that RUNX3, a gastric tumor suppressor, forms a ternary complex with beta-catenin/7CF4 and attenuates Wnt signaling activity. A significant fraction of human sporadic colorectal adenomas and Runx3(+/-) mouse intestinal adenomas showed inactivation of RUNX3 without apparent beta-catenin accumulation, indicating that RUNX3 inactivation independently induces intestinal adenomas. In human colon cancers, RUNX3 is frequently inactivated with concomitant beta-catenin accumulation, suggesting that adenomas induced by inactivation of RUNX3 may progress to malignancy. Taken together, these data demonstrate that RUNX3 functions as a tumor suppressor by attenuating Wnt signaling.

Cells deficient in the base excision repair protein, DNA polymerase beta, are hypersensitive to oxaliplatin chemotherapy

A significant proportion of human cancers overexpress DNA polymerase beta (Pol beta), the major DNA polymerase involved in base excision repair. The underlying mechanism and biological consequences of overexpression of this protein are unknown. We examined whether Pol beta, expressed at levels found in tumor cells, is involved in the repair of DNA damage induced by oxaliplatin treatment and whether the expression status of this protein alters the sensitivity of cells to oxaliplatin. DNA damage induced by oxaliplatin treatment of HCT116 and HT29 colon cancer cells was observed to be associated with the stabilization of Pol beta protein on chromatin. In comparison with HCT116 colon cancer cells, isogenic oxaliplatin-resistant (HCT-OR) cells were found to have higher constitutive levels of Pol beta protein, faster in vitro repair of a DNA substrate containing a single nucleotide gap and faster repair of 1,2-GG oxaliplatin adduct levels in cells. In HCT-OR cells, small interfering RNA knockdown of Pol beta delayed the repair of oxaliplatin-induced DNA damage. In a different model system, Pol beta-deficient fibroblasts were less able to repair 1,2-GG oxaliplatin adducts and were hypersensitive to oxaliplatin treatment compared with isogenic Pol beta-expressing cells. Consistent with previous studies, Pol beta-deficient mouse fibroblasts were not hypersensitive to cisplatin treatment. These data provide the first link between oxaliplatin sensitivity and DNA repair involving Pol beta. They demonstrate that Pol beta modulates the sensitivity of cells to oxaliplatin treatment. Oncogene (2010) 29, 463-468; doi:10.1038/onc.2009.327; published online 19 October 2009