A new insight into the interaction of cisplatin with DNA: ROA spectroscopic studies on the therapeutic effect of the drug.

Raman optical activity (ROA) spectroscopy has been applied for the first time to study the interaction of cisplatin with DNA. The knowledge about the structure of DNA-metal ion cross-links and hence the mechanism of the drug action is fundamental for the development of new antitumor drugs. At the same time, there is an urgent need to search for new methods for monitoring of this effect at the therapeutic dose of a drug. We have demonstrated that ROA spectroscopy is a sensitive technique with the capability to follow the structural alteration of the whole DNA molecule upon drug binding via a direct observation of transformation undergoing within chiral sugar moieties. A ROA profile delivers clear evidence of a partial transition from the B-DNA to the A-form due to the formation of cisplatin-DNA cross-links.