A library of drugs that are in clinical trials or use was screened for inhibitors of hypoxia-inducible factor 1 (HIF-1). Twenty drugs inhibited HIF-1-dependent gene transcription by >88% at a concentration of 0.4 μM. Eleven of these drugs were cardiac glycosides, including digoxin, ouabain, and proscillaridin A, which inhibited HIF-1α protein synthesis and expression of HIF-1 target genes in cancer cells. Digoxin administration increased latency and decreased growth of tumor xenografts, whereas treatment of established tumors resulted in growth arrest within one week. Enforced expression of HIF-1α by transfection was not inhibited by digoxin, and xenografts derived from these cells were resistant to the anti-tumor effects of digoxin, demonstrating that HIF-1 is a critical target of digoxin for cancer therapy.
|Original language||English (US)|
|Number of pages||8|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|Publication status||Published - Dec 16 2008|
- Cancer therapy
- Tumor xenograft
ASJC Scopus subject areas