Target acquired (Image: Simon Fraiser/SPL)

GENETICALLY modified stem cells are to be injected into the brains of cancer patients, where they will convert an inactive cancer drug into a potent and targeted tumour-killing agent.

Stem cells are strongly attracted towards cancer cells, so it is hoped that as well as homing in on the main tumour, they will also be drawn to secondary growths, or metastases. This will enable higher doses of drug to be delivered to cancer cells while minimising the risk of side effects in the rest of the body.

A team led by Karen Aboody at …