Mannose sugar, a nutritional supplement, may both slow tumour growth and enhance the effects of chemotherapy in multiple types of cancer, a study conducted in mice has found.
The study, published in the journal Nature, is a step towards understanding how mannose could be used to help treat cancer. Tumours use more glucose than normal, healthy tissues.
However, it is very hard to control the amount of glucose in your body through diet alone.
The researchers from the University of Glasgow in the UK found that mannose can interfere with glucose to reduce how much sugar cancer cells can use.
“Tumours need a lot of glucose to grow, so limiting the amount they can use should slow cancer progression,” said Professor Kevin Ryan from the University of Glasgow.
“The problem is that normal tissues need glucose as well, so we can’t completely remove it from the body,” Ryan said.
The study found a dosage of mannose that could block enough glucose to slow tumour growth in mice, but not so much that normal tissues were affected.
“It is hoped that finding this perfect balance means that, in the future, mannose could be given to cancer patients to enhance chemotherapy without damaging their overall health,” said Ryan.
The researchers first examined how mice with pancreatic, lung or skin cancer responded when mannose was added to their drinking water and given as an oral treatment.They found that adding the supplement significantly slowed the growth of tumours and did not cause any obvious side effects.
To test how mannose could also affect cancer treatment, mice were treated with cisplatin and doxorubicin – two of the most widely used chemotherapy drugs.The researchers found that mannose enhanced the effects of chemotherapy, slowing tumour growth, reducing the size of tumours and even increasing the lifespan of some mice.Several other cancer types, including leukaemia, osteosarcoma, ovarian and bowel cancer, were also investigated.
Researchers grew cancer cells in the lab and then treated them with mannose to see whether their growth was affected. Some cells responded well to the treatment, while others did not, they said.
It was also found that the presence of an enzyme that breaks down mannose in cells was a good indicator of how effective treatment was.
