Potential Anticancer Activity of Auranofin

Gold compounds have a long history of use in medicine. Auranofin was developed more than 30 years ago as an oral therapy for rheumatoid arthritis. Now, however, auranofin is rarely used in clinical practice despite its efficacy for treating rheumatoid arthritis because more novel antirheumatic medications are available. Although its use in clinical practice has decreased, studies on auranofin have continued and it shows promise for the treatment of several different diseases, including cancer and bacterial and parasitic infections. Several potential novel applications of auranofin for treating human disease have been proposed. Auranofin inhibits the activity of thioredoxin reductase (TrxR), an enzyme of the thioredoxin (Trx) system that is important for maintaining the intracellular redox state. Particularly in cancers, TrxR inhibition leads to an increase in cellular oxidative stress and induces apoptosis. TrxR overexpression is associated with aggressive tumor progression and poor survival in patients with breast, ovarian, and lung cancers. The Trx system may represent an attractive target for the development of new cancer treatments. Therefore, the TrxR inhibitor auranofin may be a potent anticancer agent. This review summarizes the current understanding of auranofin for cancer therapy.