A study at Tel Aviv University is said to have eradicated glioblastoma, a highly aggressive type of brain cancer.
The researchers were able to achieve this due to their discovery of two critical mechanisms in the brain that support tumour growth and survival. One protects cancer cells from the immune system, while the other supplies the energy required for rapid growth.
The work found that both mechanisms are controlled by brain cells called astrocytes, and in their absence, the tumour cells die.
The study was led by PhD student Rita Perelroizen, under the supervision of Dr Lior Mayo of the Shmunis School of Biomedicine and Cancer Research and the Sagol School of Neuroscience, in collaboration with Prof Eytan Ruppin of the National Institutes of Health (NIH) in the USA. The paper was published in the scientific journal Brain.
The crucial role of astrocytes
Mayo said: “Instead of focusing on the tumour, we focused on its supportive microenvironment, that is, the tissue that surrounds the tumour cells.
“Under the microscope we found that activated astrocytes surrounded glioblastoma tumours. Based on this observation, we set out to investigate the role of astrocytes in glioblastoma tumour growth.”
The researchers found that in the presence of astrocytes, the cancer killed all animals with glioblastoma tumours within four to five weeks. When they eradicated the astrocytes near the tumour, the cancer disappeared within days, and all treated animals survived. Even after discontinuing treatment, most animals survived.
A unique therapeutic opportunity
Next, the researchers engineered the astrocytes near the tumour to stop expressing a specific protein that transports cholesterol (ABCA1). With no access to cholesterol, the tumour essentially ‘starved’ to death in just a few days.
Mayo added: “Our findings suggest that, at least in the specific case of glioblastoma, the blood-brain barrier may be beneficial to future treatments, as it generates a unique vulnerability – the tumour’s dependence on brain-produced cholesterol. We think this weakness can translate into a unique therapeutic opportunity.”