Mannose sugar, a nutritional supplement, can both slow tumour growth and enhance the effects of chemotherapy in mice with multiple types of cancer.
This lab study is a step towards understanding how mannose could be used to help treat cancer.
The results of the study, which was funded by Cancer Research UK and Worldwide Cancer Research, are published in Nature, today (Wednesday).
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. In this study, the researchers found that mannose can interfere with glucose to reduce how much sugar cancer cells can use*.
Professor Kevin Ryan, lead author from the Cancer Research UK Beatson Institute, said: "Tumours need a lot of glucose to grow, so limiting the amount they can use should slow cancer progression. The problem is that normal tissues need glucose as well, so we can't completely remove it from the body. In our study, we 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. This is early research, but 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."
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. They 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. 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.
Professor Kevin Ryan added: "Our next step is investigating why treatment only works in some cells, so that we can work out which patients might benefit the most from this approach. We hope to start clinical trials with mannose in people as soon as possible to determine its true potential as a new cancer therapy."
Mannose is sometimes used for short periods to treat urinary tract infections, but its long-term effects have not been investigated. It's important that more research is conducted before mannose can be used in cancer patients.
Martin Ledwick, Cancer Research UK's head nurse, said: "Although these results are very promising for the future of some cancer treatments, this is very early research and has not yet been tested in humans. Patients should not self-prescribe mannose as there is a real risk of negative side effects that haven't been tested for yet. It's important to consult with a doctor before drastically changing your diet or taking new supplements."
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Peer-reviewed
Experimental study
Cells and mice
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Notes to editor
*Mannose is taken up by the same transporter as glucose and impairs glucose metabolism.
**Cells with low levels of the enzyme phosphomannose isomerase (PMI) are more sensitive to mannose treatment than cells with high levels of PMI.
About Cancer Research UK
- Cancer Research UK is the world's leading cancer charity dedicated to saving lives through research.
- Cancer Research UK's pioneering work into the prevention, diagnosis and treatment of cancer has helped save millions of lives.
- Cancer Research UK receives no funding from the UK government for its life-saving research. Every step it makes towards beating cancer relies on vital donations from the public.
- Cancer Research UK has been at the heart of the progress that has already seen survival in the UK double in the last 40 years.
- Today, 2 in 4 people survive their cancer for at least 10 years. Cancer Research UK's ambition is to accelerate progress so that by 2034, 3 in 4 people will survive their cancer for at least 10 years.
- Cancer Research UK supports research into all aspects of cancer through the work of over 4,000 scientists, doctors and nurses.
- Together with its partners and supporters, Cancer Research UK's vision is to bring forward the day when all cancers are cured.
For further information about Cancer Research UK's work or to find out how to support the charity, please call 0300 123 1022 or visit http://www.cancerresearchuk.org. Follow us on Twitter and Facebook.
About Worldwide Cancer Research
Worldwide Cancer Research is the leading UK charity, based in St Andrews, Fife, funding research into any type of cancer, anywhere in the world.
They have invested over £180 million in research grants to some of the world's best scientists across 34 different countries. The charity has 107 active projects across 17 countries happening now. http://www.worldwidecancerresearch.org.
Journal
Nature