Biomedical subjects

Raphaël Geney

Publications and source records attributed to Raphaël Geney.

6 recordsLinked to original sources

PubMed2005

Use of the tubulin bound paclitaxel conformation for structure-based rational drug design.

A new computational docking protocol has been developed and used in combination with conformational information inferred from REDOR-NMR experiments on microtubule bound 2-(p-fluorobenzoyl)paclitaxel to delineate a unique tubulin binding structure of paclitaxel. A conformationally constrained macrocyclic taxoid bearing a linker between the C-14 and C-3'N positions has been designed and synthesized to enforce this "REDOR-taxol" conformation. The novel taxoid SB-T-2053 inhibits the growth of MCF-7 and LCC-6 human breast cancer cells (wild-type and drug resistant) on the same order of magnitude as paclitaxel. Moreover, SB-T-2053 induces in vitro tubulin polymerization at least as well as paclitaxel, which directly validates our drug design process. These results open a new avenue for drug design of next generation taxoids and other microtubule-stabilizing agents based on the refined structural information of drug-tubulin complexes, in accordance with typical enzyme-inhibitor medicinal chemistry precepts.

Binding Sites↗

PubMed2004

Design and synthesis of de novo cytotoxic alkaloids through mimicking taxoid skeleton.

Based on a common pharmacophore model and the hypothesis that the baccatin core of taxoids is a scaffold securing the proper orientation of the side chains, a bicyclic alkaloid scaffold was designed as a baccatin surrogate. Using this scaffold, two novel macrocyclic and open-chain 'taxoid-mimicking' compounds were synthesized. Two of these 'taxoid-mimics', 2 and 3, were found to possess cytotoxicity with micromolar level IC50 values against human breast cancer cell lines.

Alkaloids↗

PubMed2003

BMS-184476 Bristol-Myers Squibb.

BMS-184476 is a taxane analog under development by Bristol-Myers Squibb for the potential treatment of solid tumors. By February 2001, it had entered phase II trials and, as of May 2002, phase II studies had been carried out in patients with a number of tumor types, including breast, ovarian and non-small-cell lung cancer.

Animals↗

PubMed2003

109881 Aventis.

109881 is an orally and intravenously active taxoid in development by Aventis Pharma (formerly Rhône-Poulenc Rorer) as a potential treatment for a variety of taxoid-resistant solid tumors, such as brain and lung cancers. As of April 2000, the compound was in phase IIa trials in the US, France, Belgium and Germany. Phase II trials were ongoing in May 2001, and the company was evaluating an oral formulation at this time.

Animals↗

PubMed2002

Overcoming multidrug resistance in taxane chemotherapy.

Paclitaxel (Taxol) and docetaxel (Taxotère) are currently two of the most important anticancer drugs in cancer chemotherapy. However, clinical treatment with these taxane agents often encounters undesirable side effects and multidrug resistance (MDR) caused by overexpression of P-glycoprotein (Pgp). Photoaffinity labeling of Pgp using photoreactive radiolabeled paclitaxel analogs along with molecular modeling has revealed a unique binding region for paclitaxel on the C-terminal half of Pgp. Highly efficient taxane-based MDR reversal agents (TRAs) have been developed. Extensive structure-activity relationship (SAR) studies have led to the development of new generation taxanes that possess 2-3 orders of magnitude higher potencies against human cancer cell lines expressing the MDR phenotype. One of these taxanes, SB-T-1 10131 (IDN5109, BAY59-8862), exhibits excellent activity against a variety of drug-sensitive and drug-resistant cancer cell lines as well as human tumor xenografts in mice. This taxane is orally active with excellent bioavailability, and is currently undergoing phase II human clinical trials. Novel taxane-antibody immunoconjugates have shown very promising results for tumor-specific delivery and release of an extremely cytotoxic taxane, wherein epidermal growth factor receptor is used as the specific antigen on the tumor surface of human squamous cancer xenograft in SCID mice.

ATP Binding Cassette Transporter, Subfamily B↗

PubMedDate not supplied

Electronic effects on the regio- and enantioselectivity of the asymmetric aminohydroxylation of O-substituted 4-hydroxy-2-butenoates.

Regio- and enantioselectivity in the asymmetric aminohydroxylation (AA) reaction of O-substituted 4-hydroxy-2-butenoates as well as the mechanism of the reaction were studied. When the electronic properties of the phenyl group in a substrate were altered by using different substituents, two conflicting trends were observed: The O-benzoyl substrates showed greater regio- and enantioselectivity when an electron-donating substituent was attached at the C-4 position of the phenyl group, while the O-benzyl substrates exhibited better regio- and enantioselectivity with an electron-withdrawing substituent at the C-4 position of the phenyl moiety. Thus, these results have disclosed hitherto unknown remarkable electronic effects in the AA reaction. Detailed analysis of possible electronic interactions in the chiral catalyst-substrate complex has revealed the importance of dipolar aromatic-aromatic interactions between the aromatic substituent of the substrate and the nitrogen heteroaromatic moiety of the chiral ligand for effective regiocontrol as well as enantioface selection in the AA reaction. A plausible model of the key intermediate in the AA reaction of O-substituted 4-hydroxy-2-butenoates is proposed.

Amination↗