THE BLOOD BRAIN BARRIER- NECESSARY BUT CHALLENGING
Near the top of the list of difficulties in treating DIPG is the biology of the brain’s protective layer- the blood brain barrier or ‘BBB’. Protecting against the entry of pathogens (anything that may produce disease), the BBB separates the body’s circulating blood from the delicate brain and fluids of the central nervous system. Endothelial cells form the walls of the vessels comprising the BBB and are thought to house most of the protective properties of the layer’s defence.
To study brain cancer in a laboratory, cells are isolated from brain tissue and then ‘cultured’ in a sterile flask. Optimal nutrient and temperature conditions see the cells grow and multiply, and are then used as an artificial model of the brain at a cellular level. Cell culture models of brain cancer are useful in suggesting a drug’s ability to reduce or halt cancer cell growth and induce apoptosis (cell death) but do not inform investigators as to whether a drug will reach the tumour in an animal model, or the ultimate goal, in human patients.
Dr Duchatel is currently investigating the endothelial permeability of candidate drugs for DIPG treatment. His laboratory-cultured endothelial cells will act as a model of the BBB and further guide Dr Dun’s work on selecting which pharmacological agents are likely to be most-promising in animal models based on their ability to pass from the bloodstream, into the brain, and then into the tumour itself.