Researchers have found a key player in brain tumour formation that may lead to new therapies for a deadly and incurable cancer.
The study is the first to show that a protein called OSMR (Oncostatin M Receptor) is required for glioblastoma tumours to form.
Glioblastoma is one of the most deadly cancers, resistant to radiation, chemotherapy and difficult to remove with surgery, researchers said.
"The fact that most patients with these brain tumours live only 16 months is just heartbreaking," said Arezu Jahani-Asl from University of Ottawa in Canada.
Researchers studied human brain tumour stem cells taken from glioblastoma patients.
If a single one of these brain tumour stem cells is left behind after surgery, it can create a whole new tumour. Researchers found that blocking OSMR activity in these cells prevented them from forming tumours in mouse brains.
"Being able to stop tumour formation entirely was a dramatic and stunning result. It means that this protein is a key piece of the puzzle, and could be a possible target for future treatments," said Michael Rudnicki from Ottawa Hospital.
Researchers looked at 339 tumour samples from human glioblastoma patients. They found that the higher the OSMR expression, the faster the patient died.
This was confirmed in mouse studies, where animals injected with human brain tumour stem cells with low OSMR expression lived 30 per cent longer than those infected with tumour stem cells with normal OSMR expression.
Researchers already knew that an active form of the epidermal growth factor receptor called EGFRvIII drove tumour formation in glioblastoma, but so far therapies targeting this receptor have not worked against brain cancer.
They learned that EGFRvIII needs to bind with OSMR before it can send out any tumour-forming signals.
This new understanding could pave the way for more effective treatments, not only for glioblastomas, but also for other cancers with highly amplified EGFR expression like breast, lung and cervical cancers, researchers said.
"This study raises the exciting prospect of potential new targets for a lethal disease," said Azad Bonni from Washington University in the US.
The findings were published in the journal Nature Neuroscience.
