By Eric Johnson
Prague - A team of US and Czech scientists has found that an ingredient in the milk of humans, cows and rats could be a key to preventing and treating breast cancer.
In addition, the team reported recently in the Czech Republic science journal Folia Microbiologica, their research into controlling the cellular ingredient "procathepsin D" could help in the fight against ovarian and prostate cancer.
Czech Academy of Sciences researcher Vaclav Vetvicka and colleagues from the University of Louisville spent the past 10 years experimenting with procathepsin D and its relative cathepsin D. These are molecules called peptides which are found inside cells and are controlled by hormones.
While searching for a link between procathepsin D and cancer, they found that a peptide is secreted by a cancerous cell and then apparently interacts with proteins swimming in the area between cells in ways that can help cancer spread.
"This interaction leads to the release of a signal resulting in faster growth and division of both parent and surrounding cancer cells," the researchers wrote.
The researchers reported finding an "activation peptide" that influences the overproduction and secretion of procathepsin D. This led to their conclusion that inhibiting procathepsin D could stop cancer from spreading.
The report included two suggestions for cancer treatment and prevention: immunising a person with antibodies that recognise and "bind" procathepsin D so that it cannot help cancer spread; or using gene therapy to inhibit the body's production of procathepsin D.
The research builds on earlier studies which suggested that women who breastfeed and those who were breastfed apparently have a lower risk of developing cancer.
Since procathepsin D is found in mother's milk, as well as in the milk of cows and rats, the researchers theorised that it may play a role in naturally immunising a woman against cancer.
The fact that the peptide is hormone-controlled also led the scientists to theorise that it "probably" could be used against ovarian cancer in women and prostate cancer in men. - Sapa-dpa