Brain cancers such as glioma are extraordinarily deadly.
Once diagnosed, there are no cures. This is because the brain is very difficult to access and treat safely. The current treatment is to surgically remove as much of the tumour as possible, followed by chemotherapy or radiotherapy. However, chemotherapy and radiotherapy are extremely toxic and cannot do much more than buy time before recurrence. Recurrence occurs because some cancer cells will always survive by diffusing away from the tumour, spreading deep into the healthy brain like mould spores through bread. These diffused cancer cells cannot be surgically removed, and the level of chemotherapy or radiotherapy necessary to remove them would destroy the brain.
Eliminating these diffused cancer cells is key to curing brain cancer, and the most promising approach to achieve this is to use light. Certain light wavelengths can shine through the brain without harming it. These lights can stimulate cells to produce more “ROS” molecules, by-products of cell metabolism. Picture brain cells as rechargeable batteries, and the amount of ROS in them as the amount of charge they have. Healthy cells are usually only partially charged, and so have the capacity for a bit more when stimulated. Cancer cells, on the other hand, are already fully charged, which is necessary for them to be cancerous. As a result, forcing even more charge into them causes them to overload and die.
This means that such light therapies can specifically kill cancer cells, whilst leaving healthy cells intact.
However, there is a major limitation to generating ROS with light. The only current approach to generate ROS with light is photodynamic therapy, which requires a drug to be added to the cells first. But because the brain is so difficult to access safely, getting this drug into the brain is a major issue. This drug dependence applies various limitations to the treatment, which has prevented photodynamic therapy from being widely beneficial to patients. Scientists are close to making photodynamic therapy ready for widespread clinical use following decades of refinement, but the dependence on drugs will always restrict the benefits it can achieve.
The GlioLight project aims to take some of the first steps to revolutionise the treatment of brain cancer, by developing the world’s first light therapy to generate ROS, directly, without any drugs.
“Direct Light Therapy” (DLT for short) uses 1267nm wavelength light, a very different wavelength than those used for photodynamic therapy. GlioLight partners previously demonstrated that 1267nm light can directly generate ROS and reduce tumour growth, offering a glimpse at the potential of DLT. However, these findings were very preliminary, and little is known about how DLT works or how to use it best.
Enter the GlioLight project, which aims to investigate the effects of 1267nm light on glioma and healthy brain cells, optimise treatment regimens for best outcomes, and develop hardware that may one day deliver DLT to human brains. The path to bring DLT technology to the clinic to benefit those suffering from cancer will be long, challenging, and full of uncertainty. It may be decades before the technology is ready for the world, but GlioLight could be the seed that eventually grows into the cure for glioma and other brain cancers.