Scientists break blood-brain barrier to allow cancer drugs in

Oxford University scientists have found a way of delivering drugs more effectively to treat life-threatening cancers that have spread to the brain. The study, in mice and tissue samples, used a protein called TNF that can track down sites in the brain where cancer has spread by recognising a marker found only on tumour blood vessels. The researchers found that TNF can home in on these sites and temporarily open the blood-brain barrier (BBB) allowing drugs to pass from the blood system into the tumour. The BBB acts as a shield that prevents potentially dangerous particles such as bacteria entering the brain. But it's this same shield that stops cancer drugs reaching tumours that have spread to the brain. The TNF protein only broke down the BBB in the blood vessels that pass through the tumour, leaving the healthy parts of the brain undamaged by potentially toxic drugs. The research showed that when TNF is injected into the bloodstream, the breast cancer drug herceptin (trastuzumab) - which is not normally able to cross the BBB - can reach cancer cells in the brain.