In a significant step forward for the development of a potential new cancer treatment, scientists have found how a common cold virus can kill tumours and trigger an immune response, like a vaccine, when injected into the blood stream.
Researchers from Britain's Leeds University and the Institute of Cancer Research (ICR) said by hitching a ride on blood cells, the virus was protected from antibodies in the blood stream that might otherwise neutralise its cancer-fighting abilities.
The findings suggest viral therapies like this, called reovirus, could be injected into the blood stream at routine outpatient appointments - like standard chemotherapy - making them potentially suitable for treating a range of cancers.
The study, part-funded by the charity Cancer Research UK and conducted on 10 patients with advanced bowel cancer, confirmed that reovirus attacks on two fronts - killing cancer cells directly and triggering an immune response that helps eliminate leftover cancer cells.
"Viral treatments like reovirus are showing real promise in patient trials. This study gives us the very good news that it should be possible to deliver these treatments with a simple injection into the blood stream," said Kevin Harrington from ICR, who co-led the study and published it in the journal Science Translational Medicine on Wednesday.
Harrington said if viral treatments had been found only to work when injected directly into tumours, that would have been a significant barrier to their widespread use.
"But the finding that they can hitch a ride on blood cells will potentially make them relevant to a broad range of cancers," he said.
Reovirus is being investigated by several research teams around the world - including scientists at Canada's Oncolytics Biotech Inc - because it has shown an ability to infect and kill cancer cells without affecting normal tissue.
"We also confirmed that reovirus was specifically targeting cancer cells and leaving normal cells alone, which we hope should mean fewer side-effects for patients," Harrington said.
Cancer killed 7.6 million people worldwide in 2008, the most recent year for which the World Health Organisation has full data. The number of cancer cases is expected to surge by more than 75 percent across the world by 2030.
The 10 patients in the study were all due to have surgery on tumours that had spread to their livers. During outpatient appointments in the weeks before their surgery, they were given up to five doses of the experimental reovirus treatment.
When researchers looked at pieces of tissue removed during surgery up to four weeks later, they found what they described as "viral factories" of active virus in the tumour - but not in the normal liver tissue.
This confirmed the reovirus had been delivered specifically to the cancer cells after being injected into the blood stream.
"It seems that reovirus is even cleverer than we had thought," said University of Leeds' researcher Alan Melcher.
"By piggybacking on blood cells, the virus is managing to hide from the body's natural immune response and reach its target intact. This could be hugely significant for the uptake of viral therapies like this in clinical practice."
El Nino has devastated Mozambique's Gorongosa park with political tensions threatening the park
Cupping therapy is an ancient form of alternative medicine in which a therapist puts special cups on skin for a few minutes to create suction, the therapy itself dates back to the time of the Prophet Muhammad.
The Earth has hit a record high with an overall globel temperature the highest ever on record
The National Institute of Health may fund research into mixed embryos to better understand human diseases and develop therapies to treat them.
Travel across multiple time zones disrupts circadian rhythms resulting in jet lag
After five years the radiation levels in the Pacific Ocean are close to normal levels after a nuclear meltdown in the city
A trilateral pledge will see a jump from the current collective clean power levels of about 37% to 50% by 2025
Around 6.5 million deaths globally are attributed each year to poor air quality inside and outside, making it the world's fourth-largest threat to human health, behind high blood pressure, dietary risks and smoking
New World Drug Report research identifies heroin as deadliest drug
Zika has caused alarm throughout the Americas since cases of the birth defect microcephaly were reported in Brazil, the country hardest hit by the outbreak
Philadelphia has become the first big city in the US to place a tax on soda to tackle the obesity crisis
Average global temperatures startlingly higher than normal between March-May
Government study provides strongest evidence of cell phone health effects
The reason for the high-level threat in the area is the presence there of Aedes aegypti mosquitoes, which carry the Zika virus that health authorities say causes birth defects in newborns
Three-day African Utility Week conference begins in South African city of Cape Town