Drug to reactivate immune cells could treat brain cancer

Researchers in Canada have discovered that glioblastoma samples contained certain types of immune cells that usually fight tumour generating cells. It was found that reactivating the immune cells by administering a new drug to mice that had glioblastomas, resulted in the animals living for a longer period of time compared to mice that were not treated with the drug. 

The study, performed by researchers from the University of Calgary's Hotchkiss Brain Institute (HBI) and Southern Alberta Cancer Research Institute, was published in 'Nature Neuroscience'.

Glioblastoma is the most deadly form of brain cancer and, while treatments already exist, patients diagnosed with this type of tumour have an average survival time of only 15 months. Less than one in 20 live for more than five years after diagnosis. 

Brains contain immune cells called microglia that help to protect against infection and injury. They work like immune cells in other areas of the body and so detect stem cells than are becoming tumour cells - brain tumour initiating cells (BTICs) - which grow very quickly within the brain, ultimately becoming a tumour. 

While the microglia works to destroy the cancerous cells before they become a tumour, eventually the BTICs are able to disable them, resulting in rapid tumour growth, explains Dr V. Wee Yong from the Southern Alberta Cancer Research Institute.

The first phase of the study included taking microlgia from patients without and gliomas to be cultured with BTICs from patients with gliomas. It was found that the microglia were successfully able to stop of the BTICs from growing. 

The researchers then moved on to testing the drug amphotericin B (AmpB) in mice that had brain tumours that were caused by both mouse and human-derived BTICs. Daily treatment of the mice with the drug successfully reactivated the mice's microglia, resulting in the slowing of tumour growth.  

While the drug is quite a harsh one, according to Doctor Yong, the study found that when administered in small doses, it was both effective and well tolerated. AmpB has never been used in human treatment, but it could be used in future clinical trials due to these promising results.