RESUMEN
Inhibitors of the Hsp90 molecular chaperone are showing considerable promise as potential chemotherapeutic agents for cancer. Here, we describe the structure-based design, synthesis, structure-activity relationships and pharmacokinetics of potent small-molecule inhibitors of Hsp90 based on the 4,5-diarylisoxazole scaffold. Analogues from this series have high affinity for Hsp90, as measured in a fluorescence polarization (FP) competitive binding assay, and are active in cancer cell lines where they inhibit proliferation and exhibit a characteristic profile of depletion of oncogenic proteins and concomitant elevation of Hsp72. Compound 40f (VER-52296/NVP-AUY922) is potent in the Hsp90 FP binding assay (IC50 = 21 nM) and inhibits proliferation of various human cancer cell lines in vitro, with GI50 averaging 9 nM. Compound 40f is retained in tumors in vivo when administered i.p., as evaluated by cassette dosing in tumor-bearing mice. In a human colon cancer xenograft model, 40f inhibits tumor growth by approximately 50%.
Asunto(s)
Antineoplásicos/síntesis química , Proteínas HSP90 de Choque Térmico/antagonistas & inhibidores , Isoxazoles/síntesis química , Resorcinoles/síntesis química , Animales , Antineoplásicos/farmacocinética , Antineoplásicos/farmacología , Unión Competitiva , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Cristalografía por Rayos X , Ensayos de Selección de Medicamentos Antitumorales , Polarización de Fluorescencia , Proteínas HSP90 de Choque Térmico/metabolismo , Humanos , Isoxazoles/farmacocinética , Isoxazoles/farmacología , Ratones , Ratones Desnudos , Modelos Moleculares , Trasplante de Neoplasias , Resorcinoles/farmacocinética , Resorcinoles/farmacología , Relación Estructura-Actividad , Trasplante HeterólogoRESUMEN
Starting from the tetrapeptide Ac-pYEEI-NHMe and using a structure-based approach, we have designed and synthesised a peptidomimetic ligand for p56(lck) SH2 domain containing a conformationally restricted replacement for the two glutamate residues. We have explored replacments for the isoleucine residue in the pY+3 pocket and thus identified 1-(R)-amino-3-(S)-indaneacetic acid as the most potent replacement. We also report the X-ray crystal structures of two of the antagonists.
