A simple yeast-based system for analyzing inhibitor resistance in the human cancer drug targets Hsp90 alpha/beta

作者：Millson Stefan H; Prodromou Chrisostomos; Piper Peter W^*

来源：Biochemical Pharmacology, 2010, 79(11): 1581-1588.

DOI：10.1016/j.bcp.2010.01.031

• Hsp90
• Molecular chaperone
• Cancer
• Drug target
• Drug resistance
• Yeast

Heat shock protein 90 (Hsp90), a highly conserved molecular chaperone, is one of the most promising targets for cancer drug development. Whether any resistance to these Hsp90 inhibitor drugs could arise by Hsp90 mutation is still unknown. Yeast is readily engineered so that its essential Hsp90 function is provided by either isoform of the human cytosolic Hsp90, Hsp90 alpha or Hsp90 beta. However, its high intrinsic resistance to most drugs poses a major obstacle to the use of such Hsp90 alpha- or Hsp90 beta-expressing yeast cells as a model system to analyse whether drug resistance might arise by Hsp90 mutation. In order to overcome this problem, we have generated a strain that is both hypersensitive to Hsp90 inhibitors as it lacks multiple drug resistance genes, and in which different heterologous and mutant Hsp90s can be expressed by plasmid exchange. It is not rendered appreciably stress sensitive when made to express Hsp90 alpha or Hsp90 beta as its sole form of Hsp90. Should there be any development of resistance to the Hsp90 drugs now in cancer clinic trials, this system can provide a rapid initial test of whether any single nucleotide polymorphism appearing within the coding regions of Hsp90 alpha or Hsp90 beta could be a contributory factor in this resistance. We have used this strain to demonstrate that significant levels of resistance to the Hsp90 inhibitors radicicol and 17-allylamino-demethoxygeldanamycin (17-AAG) are generated as a result of the same single point mutation within the native Hsp90 of yeast (A107N), the human Hsp90 alpha. (A121N) and the human Hsp90 beta (A116N).

• 出版日期2010-6-1