An extract from a wild flower could one day be used to treat a wide range of aggressive cancers, a study suggests.
The discovery could lead to new treatments
Researchers in the United States have found that cyclopamine, which is a compound of corn lily, may be able to shrink tumours.
They believe it could be an effective treatment for cancer of the pancreas, stomach, oesophagus and biliary tract.
The tests were carried out on mice and on human cells in a laboratory, so further studies are needed to see if it could be effective in humans.
However, other research has also indicated that cyclopamine may help in the fight against cancer.
A study published last year suggested it may be able to treat medulloblastoma - the most common form of aggressive brain cancer in children.
Another study, published earlier this year, found it could stop the damage done to the lungs by smoking and prevent lung cancer.
These latest findings, published in Nature, are based on two separate studies.
In the first study, Dr Philip Beachy and colleagues at Johns Hopkins University School of Medicine found that high levels of a protein called Sonic Hedgehog - named after the cartoon character - may trigger tumours in the oesophagus, stomach, biliary tract and pancreas.
This protein plays an important role in the early development of unborn babies, helping them to grow.
However, there is a growing belief that if it is activated later in life it may trigger cancer.
In tests on mice, the researchers were able to use cyclopamine to block this protein.
After 12 days of treatment, they found that the tumours were significantly smaller.
Tests on mice
In the second study, Dr Sarah Thayer and colleagues at Massachusetts General Hospital and Harvard Medical School found that cyclopamine had a similar impact on mice with cancer of the pancreas.
The findings have raised hopes that cyclopamine could be a potentially new treatment for these types of cancer.
"The hedgehog signalling pathway has been implicated in a number of different cancers," said Elaine Vickers of Cancer Research UK.
"Two new studies provide evidence that it is overactive in cancers of the oesophagus, stomach and pancreas, all of which are currently difficult to treat.
"The researchers also demonstrate that cyclopamine, a compound that targets the hedgehog pathway, is an effective treatment for these cancers in mice.
"Cancers of the digestive system are responsible for many thousands of deaths each year in the UK and new treatments are the focus of much research.
"Cyclopamine could represent an exciting anti-cancer compound but the results so far have been limited to mice.
"Many years of further investigation are needed before we know whether targeting the hedgehog pathway has any use in treating human cancer."