Anti-Tumour Potential of Gold Compounds
The use of gold compounds in medicine, namely for the remediation of the symptoms associated with rheumatoid arthritis (RA), is well known. Subsequently, other medicinal applications of gold compounds have been investigated. Thus, gold compounds have been evaluated for anti-HIV, anti-malarial and anti-tumour activities. It is the putative anti-tumour activity of gold compounds, both gold(I) and gold(III), that will form the focus of this presentation .
Interest in the anti-tumour activity of gold(I) compounds has a firm foundation based on the observation that patients undergoing chrysotherapy, i.e. gold therapy, had reduced rates of malignancy. Work on gold(III) species most likely arises from the wide use of cisplatin, containing the isoelectronic platinum(II) centre. This overview will summarise advances in research towards developing new anti-tumour drugs containing gold as gold(I) and gold(III). Targeting biological targets such as mitochondrial DNA by tetrahedrally coordinated gold(I) phosphine complexes and DNA by square planar gold(III) species are both aspects of this search for new drugs undergoing investigation. In the same way, the generation of heterometallic species and those containing functionalised phosphines are also under scrutiny. One of the most potent series of gold(I) compounds are the phosphinegold(I) thiolates, i.e. analogues of auranofin, an orally-administered drug used in the treatment of RA. High levels of activity are often observed, especially when the thiolate ligand is derived from a sulfur-containing drug or metabolite. Particularly exciting is the high cytotoxcity exhibited by certain phosphinegold(I) thiolates in cisplatin-resistant cell lines, the apparent specificity against certain cancer cell lines and high levels of tolerance in small mammals.
Acknowledgements. On-going work in this area is supported by National University of Singapore (R-143-000-139-112) and the Biomedical Research Council (Singapore).
 E.R.T. Tiekink, Critical Reviews in Oncology/Hematology, 2002, 42, 225-248.
drug, arthritis, Cancer, thiolate, phosphine, Gold