NCIt definition : The hydrochloride salt of a small-molecule inhibitor of heat shock protein 90 (HSP90)
with antiproliferative and antineoplastic activities. Retaspimycin binds to and inhibits
the cytosolic chaperone functions of HSP90, which maintains the stability and functional
shape of many oncogenic signaling proteins and may be overexpressed or overactive
in tumor cells. Retaspimycin-mediated inhibition of HSP90 promotes the proteasomal
degradation of oncogenic signaling proteins in susceptible tumor cell populations,
which may result in the induction of apoptosis.;