Platinum Metals Rev., 1962, 6, (3), 91
Complex Platinum Compounds and Virus Activity
A Possible Means of Attack on Cancer Tumours
Among the many researches being undertaken into the likely causes and possible treatments of cancer, evidence has been accumulating to indicate that viruses may be involved in many types of the disease. Viruses contain proteins, nucleic acids and polypeptide linkages and therefore present obvious possibilities as co-ordinating agents for certain metal ions, with the further possibility that complex inorganic compounds might be used successfully in destroying or reducing their disease-producing activity.
At the meeting of the American Chemical Society held in Washington, D.C., in March a valuable step forward in this direction was reported by Dawn Francis, Dr Stanley Kirchner and Dr J. C. Bergman of the Department of Chemistry, Wayne State University, Detroit, working in collaboration with Dr Yung-Kang Wei of the National Research Council, Ottawa. Because it would be impossible to introduce a metal ion into a living system with the expectation that it would by-pass normal proteins and await complexing by co-ordination sites in the virus, these workers proposed to introduce metal ions as co-ordination complexes of intermediate stability; in this way it was hoped that they would be stable enough to escape reaction with normal proteins but not so stable as to resist attack by virus proteins.
Some complex inorganic compounds are known to be carcinostatic, among them 6-mercaptopurine, and the preparations made and tested in this research included this biologically active compound and its complexes with platinum and palladium. In tests with cancer tumours in mice, these latter two compounds proved to be extremely active, showing in fact a much greater activity than that of 6-mercaptopurinc itself. These results certainly lend support to the hypothesis put forward, but further closely controlled tests with 6-mercaptopurine on both complexed and uncomplexed forms are now being conducted.