This topic has been dominated in recent years by the use of platinum complexes in the clinical treatment of cancer but covers a broad field ranging from effects on viruses, bacteria, use of gold complexes in arthritis, and even nitroprusside as a vasodilator. All these uses and effects have their origin in the inorganic chemistry of these complexes and their interactions with biological molecules. In platinum antitumor chemistry our objective is to design and develop complexes acting by new mechanisms of action. Complexes acting by different mechanisms may display an altered spectrum of antitumor activity and especially activity in cisplatin-resistant lines. Two disadvantages are, however, that the complexes have limited activity against many common human cancers and that they are susceptible to the phenomenon of acquired drug resistance.
Resistance arises for a number of reasons and enhanced repair of DNA lesions is an important factor.
Thus, there may exist a molecular mechanism to overcoming resistance. These features are further correlated with the antitumor activity and compared with the relevant properties of cisplatin. These series are of particular interest because they must, by definition, bind to DNA in a different manner to cisplatin. Thus, at least two demonstrably different mechanisms to cisplatin must operate. These are the first new mechanisms shown to operate for platinum complexes.