Geldanamycin is a benzoquinone ansamycin antibiotic that binds to Hsp90 (Heat Shock Protein 90) and alters its function. HSP90 client proteins play important roles in the regulation of the cell cycle, cell growth, cell survival, apoptosis, angiogenesis and oncogenesis.

Geldanamycin induces the degradation of proteins that are mutated in tumor cells such as v-Src, Bcr-Abl and p53 preferentially over their normal cellular counterparts. This effect is mediated via HSP90. Despite its potent antitumor potential, geldanamycin presents several major drawbacks as a drug candidate (namely, hepatotoxicity) that have led to the development of geldanamycin analogues, in particular analogues containing a derivatisation at the 17 position:

• 17-AAG
• 17-DMAG

References

• Bedin M, Gaben AM, Saucier C, Mester J. Int J Cancer. 2004 May 1;109(5):643-52. Geldanamycin, an inhibitor of the chaperone activity of HSP90, induces MAPK-independent cell cycle arrest.