Sunday, August 1, 1999 Published at 16:19 GMT 17:19 UK
Protein brakes prostate cancer
Most prostate cancers are surgically removed
A protein can prevent the aggressive form of prostate cancer from spreading to other parts of the body, say scientists.
Although the discovery was made using rats, the researchers say the finding will help develop new therapies for the human form of the disease.
Prostate cancer is one of the most common forms of cancer, affecting many men in middle age.
Often it is discovered early and can be surgically removed, but if it proves aggressive it can spread and attack the rest of the body.
Professor Mark Hendrix led the research at the University of Iowa and published her team's findings in the journal Cancer Research.
"The results of this study provide a potential new therapeutic strategy for targeting invasive prostate cancer," she said.
The team found that restoring levels of a protein called E-cadherin prevents the cancer spreading.
Professor David Lubaroff, who took part in the research, said: "The correlation between the expression of the E-cadherin protein and the spreading of prostate cancer to distant sites may provide a nother weapon in the battle against this deadly disease."
The researchers already knew that there were reduced levels of E-cadherin in patients with advanced cancer, and some research suggested there was a direct link between levels of the protein and the ability of cancer to spread.
However, until now there was no direct evidence that restoring levels of the protein - which helps hold cells together - could inhibit the progress of the cancer.
The University of Iowa team took prostate cancer cells from a rat and restored the missing E-cadherin.
This caused the cancer cells to stick together, suggesting that they would be unlikely to break off and spread around the body.
The team is now looking at developing gene therapies to apply the discovery to humans.
Professor Hendrix said: "The outcome of these studies could form the basis of the development of new clinical strategies for the treatment of prostate cancer."
And Professor Richard Williams, head of urology at the university, said: "This study is a prime example of the enormous potential that molecular biologic techniques have to change the behaviour of cancer cells.
"When directly applied to patients, this discovery raises great hope of limiting the spread of prostate cancer within the body and thus improving survival."