Researchers in Spain have developed a way to monitor the effects of chemotherapy drugs which they say could lead to better targeted, less aggressive treatments for cancer patients.

Maria Montes-Bayón and colleagues at the University of Oviedo have found a method to quantify the points, called adducts, on DNA where an anticancer drug binds. The approach could lead to better understanding and monitoring of the treatment process, said Montes-Bayón.

The team incubated DNA with the anticancer drug, cisplatin and treated the mixture with an enzyme that cut the DNA into small fragments. The group used an HPLC column to separate the DNA mixture and a mass spectrometer to monitor the levels of phosphorus and platinum in the separated fragments. In this way, they could detect and quantify where the platinum-containing drug had bound to the phosphorus-containing DNA.

Platinum-containing drugs work by inhibiting DNA replication in cancer cells and stopping them dividing, explained Montes-Bayón. Although cisplatin is mainly selective for tumour cells, it can also affect healthy cells, causing unpleasant side effects in patients undergoing chemotherapy. Montes-Bayón said that the team's aim was to make anticancer treatments more selective for tumour cells and less unpleasant for the patients. For this they needed to better understand the processes occurring and be able to monitor them.

Jörg Bettmer from the Johannes Gutenberg University of Mainz, Germany, said that Montes-Bayón's approach 'clearly demonstrates the common value of complementary elemental and structural mass spectrometry in biochemical applications.'

So far the team have worked with DNA samples in vitro. Montes-Bayón said that future work would involve investigating adducts formed in living cells.

Michael Smith