Starving cancer cells of their oxygen supply could help them kill deadly tumours, new research suggests.
The simple technique, inspired by mountain climbers’ altitude training, ‘toughens up’ the immune system to seek and destroy tumours.
Israeli scientists showed the new immunotherapy treatment bolstered T cells – white blood cells with the specialised role of killing harmful cells.
Depriving the cells of oxygen shrunk tumours more effectively than conventional immunotherapy methods.
The simple technique, inspired by mountain climbers’ altitude training, ‘toughens up’ the immune system to seek and destroy tumours
Lead author Professor Guy Shakhar, from the Weizmann Institute of Science, said: ‘Killer T cells are the foot soldiers of cancer immunotherapy.
‘They are the ones to target and destroy cancerous cells, but they don’t always manage to eliminate the malignancy.
‘We’ve shown that by growing these T cells in an oxygen-poor environment, we can turn them into more effective killers.’
He added: ‘Just as altitude training increases endurance in humans, putting killer T cells through a ‘fitness regimen’ apparently toughens them up.’
The benefits of immunotherapy
Harnessing the immune system to battle malignancy – known as immunotherapy – has already started saving the lives of cancer patients in the past few years.
In one major version of this approach, T cells are removed from the patient’s blood and adapted to destroy cancerous cells. They are then returned.
This method has so far worked best against certain leukaemias and lymphomas, but not against solid tumors, trials have shown.
The new study of oxygen starvation, published in Cell Reports, is the first to show an effect against solid tumours.
It is also the first ever report on the cancer-fighting ability of oxygen starved T cells, the team of researchers said.
How was the study carried out?
For the laboratory trial on mice, the scientists grew T cells in an incubator with an oxygen concentration of just 1 per cent.
Altitude training teaches athletes to cope with oxygen concentrations of as low as 6.9 per cent – which is what climbers feel at the top of Mount Everest.
One group of mice were injected with the oxygen-starved T cells. The other were given T cells grown in normal conditions.
What did they find?
Oxygen-starved T cells proved much more effective at fighting the cancer, the results showed.
Mice treated with these cells lived longer and their tumors shrank much more dramatically compared with the mice treated with regular T cells.
However, it wasn’t because the oxygen-starved T cells penetrated tumours better – it was because they had higher levels of a destructive enzyme called granzyme B, which penetrates and kills cancerous cells.
If the findings are repeated in human trials, they could lead to an immediate means of improving immunotherapy against solid tumours.