Cancer research: Breakthrough gives treatment hope
Scientists have identified the process behind the development of some of the most lethal forms of breast cancer known to medical science.
Researchers at the Dana-Farber Cancer Institute pinpointed a complex sequence of molecular interactions that only occur in 10% of breast cancers, including some of the deadliest.
The sequence begins with the over-production of cyclin D1, a common protein that helps control cell growth.
This serves to over-stimulate a molecular switch, known as CDK4 kinase, which in turn leads it to release a number of virulent cancer cells.
If these cells contain a mutated malign form of the HER2 gene, they are notoriously difficult to treat.
According to one recent study, the seven-year survival rate for women suffering from breast cancers involving the HER2 gene was just 13%.
Herceptin, the breast cancer drug that has hit the headlines due to the health service's refusal to pay for it, has shown promising signs of inhibiting HER2 mutation. Other drugs, such as Gleevec, also work by disrupting the action of kinases.
The researchers treated mice with a combination of genes to shed light on the chemistry between each part of the sequence.
They found that the interaction between cyclin D1 and CDK4 was not only behind the creation of cancer cells, but that the uninterrupted continuation of that process was vital for cancer growth to continue.
The scientists believe their discovery may prove crucial in the development of a drug that blocks CDK4 and could be used in conjunction with Herceptin to treat patients with particularly aggressive breast tumours.
"We are going to see in the next five years a movement away from treating all tumours with the same drugs and instead match specific drugs to tumours based on their molecular characteristics," said Dr Peter Sicinski, researcher at the Dana-Farber institute.
"Scientists now need to show that inhibiting CDK4 function can actually disrupt breast cancer growth, and then find a safe, reliable way of doing so in cancer patients.
"This process may take many years, but results like these show the progress we are making in our understanding of how cancer develops and how we could treat it even more successfully," he added.
