A genetically engineered virus that is linked to the common cold has shown promise as a treatment for aggressive brain tumours.
Glioblastoma is the most common and fatal type of brain cancer, with most patients surviving fewer than 14 months after diagnosis.
Current treatments include surgery, radiotherapy and chemotherapy - but these do not significantly improve prognosis.
Researchers from Queen Mary University of London, the Chinese Academy of Sciences and Capital Medical University in Beijing genetically engineered an adenovirus, a type of virus associated with common colds, to deliver potent immune-boosting proteins to eight patients with glioblastoma tumours.
They found that it was safe and effective, and complete remission was achieved in one patient.
The protein can slow the growth of tumours but is very toxic in its natural form.
To limit its toxicity, researchers engineered a version that restricts its release from cells, limiting it to the area surrounding the tumour.
Professor Yaohe Wang, co-lead author of the study and inventor of the virus being tested, said: “Most existing oncolytic viruses are ineffective at low doses and too toxic at higher doses.
“The key challenge is how to increase efficacy without causing harmful side effects.
“We believe our approach offers a way forward.”
He added: “It’s like yin and yang.
“This virus enhances the positive signals that encourage the immune system to attack the tumour, but it could also be paired with treatments that block the tumour’s ability to suppress the immune system.”
The use of genetically engineered viruses to target cells is known as oncolytic virotherapy.
Scientists have previously explored whether the Zika virus could be used to destroy brain cancer cells.
Researchers from Duke-NUS Medical School found that the Zika virus vaccine was able to target fast-growing cancerous cells in the adult brain.
In 2015, the US Food and Drug Administration (FDA) approved the first oncolytic virus immunotherapy for the treatment of skin cancer.
The treatment involves a herpes virus that has been engineered to be less likely to infect healthy cells but also produce an immune-boosting protein called GM-CSF.
