The Development of Hsp90β-Selective Inhibitors to Overcome Detriments Associated with pan-Hsp90 Inhibition

The 90 kD heat shock proteins (Hsp90) are molecular chaperones that are responsible for the folding of select proteins, many of which are directly associated with cancer progression. Consequently, inhibition of the Hsp90 protein folding machinery results in a combinatorial attack on numerous oncogenic pathways. Seventeen small-molecule inhibitors of Hsp90 have entered clinical trials for the treatment of cancer, all of which bind the Hsp90 N-terminus and exhibit pan-inhibitory activity against all four Hsp90 isoforms, which may lead to adverse effects. The development of Hsp90 isoform-selective inhibitors represents an alternative approach toward the treatment of cancer and may limit some of these detriments. Described herein, is a structure-based approach to develop isoform-selective inhibitors of Hsp90 beta, which induces the degradation of select Hsp90 clients without concomitant induction of Hsp90 levels. Together, these initial studies support the development of Hsp90 beta-selective inhibitors as a method for overcoming the detriments associated with pan-inhibition.

Automated summary

Hsp90 proteins play a crucial role in cancer progression, and inhibiting their activity may be beneficial for cancer treatment. Current Hsp90 inhibitors target all isoforms, potentially leading to adverse effects. Utilizing Hsp90 beta-selective inhibitors as a new approach for cancer therapy holds promise in reducing side effects.