Development of a Purine-Scaffold Novel Class of Hsp90 Binders that Inhibit the Proliferation of Cancer Cells and Induce the Degradation of Her2 Tyrosine Kinase
摘要:
The first published synthesis and characterization of a purine-scaffold library of hsp90 inhibitors is presented. The purine-scaffold represents a platform for the creation of easily synthesizable and derivatizable soluble molecules that are amenable for oral administration. The most active compound of the series (71) exhibits binding to hsp90 comparable to the natural product derivative 17AAG that is now in Phase I clinical trial as a cancer therapeutic. 71 Induces the degradation of Her2 tyrosine kinase and arrests the MCF-7 breast cancer cell line at low micromolar concentrations (IC50 = 2 muM). (C) 2002 Elsevier Science Ltd. All rights reserved.
Development of a Purine-Scaffold Novel Class of Hsp90 Binders that Inhibit the Proliferation of Cancer Cells and Induce the Degradation of Her2 Tyrosine Kinase
摘要:
The first published synthesis and characterization of a purine-scaffold library of hsp90 inhibitors is presented. The purine-scaffold represents a platform for the creation of easily synthesizable and derivatizable soluble molecules that are amenable for oral administration. The most active compound of the series (71) exhibits binding to hsp90 comparable to the natural product derivative 17AAG that is now in Phase I clinical trial as a cancer therapeutic. 71 Induces the degradation of Her2 tyrosine kinase and arrests the MCF-7 breast cancer cell line at low micromolar concentrations (IC50 = 2 muM). (C) 2002 Elsevier Science Ltd. All rights reserved.
Structural differences in binding pockets of members of the HSP90 family can be exploited to achieve differential degradation of kinases and other signaling proteins through the use of designed small molecules which interact with the N-terminal binding pocket with an affinity which is greater than ADP and different from the ansamycin antibiotics for at least one species of the HSP90 family. Moreover, these small molecules can be designed to be soluble in aqueous media, thus providing a further advantage over the use of ansamycin antibiotics. Pharmaceutical compositions can be formulated containing a pharmaceutically acceptable carrier and a molecule that includes a binding moiety which binds to the N-terminal pocket of at least one member of the HSP90 family of proteins. Such binding moieties were found to have antiproliferative activity against tumor cells which are dependent on proteins requiring chaperones of the HSP90 family for their function. Different chemical species have different activity, however, allowing the selection of, for example Her2 degradation without degradation of Raf kinase. Thus, the binding moieties possess an inherent targeting capacity. In addition, the small molecules can be linked to targeting moieties to provide targeting of the activity to specific classes of cells. Thus, the invention further provides a method for treatment of diseases, including cancers, by administration of these compositions. Dimeric forms of the binding moieties may also be employed.