Spanish scientist in landmark cancer discovery
12 April 2007, BARCELONA - A Spanish scientist is behind a landmark discovery of four genes responsible for the lethal spread of breast cancer.
12 April 2007
BARCELONA - A Spanish scientist is behind a landmark discovery of four genes responsible for the lethal spread of breast cancer.
Prof Joan Massague led the team which found a new insight into how to treat the disease more effectively.
A number of genes are already known to contribute to the spread to the lungs.
But Prof Joan Massagué and colleagues at Memorial Sloan Kettering Cancer Centre, New York, now show how four co-operate to promote the formation of new tumour blood vessels, the release of cancer cells into the bloodstream, and the penetration of tumour cells from the bloodstream into the lung.
The gene set comprises EREG, MMP1, MMP2 and Cox2 and the abnormal activation of all four enables the breast cancer to invade the lungs.
Although shutting off these genes individually can slow cancer growth and metastasis, the researchers found that turning off all four had a dramatic effect.
Prof Massagué said: "The remarkable thing was that while silencing these genes individually was effective, silencing the quartet nearly completely eliminated tumour growth and spread."
In experiments on human breast tumours implanted in mice, the researchers also found that they could reduce the growth and spread of the disease by simultaneously targeting two of the proteins produced by these genes, using drugs already on the market. "We found that the combination of these two inhibitory drugs was effective, even though the drugs individually were not very effective," said Prof Massagué. "This really nailed the case that if we can inactivate these genes in concert, it will affect metastasis."
The researchers now want to test combination therapy with the drugs - cetuximab (trade name Erbitux) and celecoxib (Celebrex) - to treat breast cancer metastasis.
The other two genes are matrix metalloproteinases (MMP1 and MMP2) that participate in the formation of new blood vessels. Although there are efforts to find drugs to inhibit them, none is in clinical use "owing to toxicities due to the large number of MMPs that function normally in our bodies and that the existing inhibitors may be acting on", said Prof Massagué.
His team is now studying the genes that enable breast cancer to spread to other parts of the body, such as the bone.
A second study published in Nature, shows that scientists in Texas have isolated 87 genes that seem to affect how sensitive human cancer cells are to certain chemotherapy drugs.
The study highlights a new way to screen for alterations in cancer cells that make them specifically sensitive to treatments, so that they may leave normal tissue relatively unharmed.
[Copyright EFE with Expatica]
Subject: Spanish news