Tricking the immune system into attacking tumors.

Nature reports on Chinese researchers who found a way to make the body get rid of cancer — by disguising tumors as transplanted pig organs, so the body rejects them:

Immunologist and surgeon Yongxiang Zhao at Guangxi Medical University in Nanning, China, wondered whether he could harness this runaway immune response and direct it against tumours.

To do so, Zhao and his colleagues combined lessons from transplant medicine with an anti-cancer strategy called oncolytic virotherapy, which has been around for decades, Litchy says. This approach harnesses viruses to either attack cancer cells or provoke the immune system into doing so.

For this therapy, Zhao’s team chose Newcastle disease virus, which can be fatal to birds, but causes only mild disease or none at all in humans. Applied to tumours on its own, the virus fails to elicit an immune response that is strong enough to be helpful clinically. So the team engineered Newcastle disease viruses to carry the genetic instructions for an enzyme called α 1,3-galactotransferase. This enzyme decorates cells with certain pig sugars — the very ones that provoke a fierce antibody attack in humans who receive a pig-organ transplant.

The researchers first tested the therapy in cynomolgus monkeys (Macaca fascicularis). Five monkeys with liver cancer that received only saline died an average of four months after treatment. But five monkeys with cancer that received the enzyme-encoding virus survived for more than six months.

The researchers then tested the enzyme-encoding virus in 23 people who had a variety of treatment-resistant cancers, including those of the liver, oesophagus, rectum, ovaries, lung, breast, skin and cervix…. Only two participants did not receive any benefit from the treatment, although two other people dropped out of the trial before the end of the first year.


You can read more of Zhong’s research here, in Cell.