Business Weekly - Cambridge, UK

A study conducted by the University's Pathology department has found that the cell-signalling molecules employed by the body's immune system, cytokines, also have a direct effect on milk production in breast cells, creating signals that could be misinterpreted and lead to the formation of cancer.

In the event of an immune response to viral or parasitic invasion, the body produces cells to attack and repel the foreign bodies.

To keep up the number of defenders, each new cell releases signalling compounds called cytokines to stimulate the continued production of immune cells.

The recent study, conducted by Dr Walid Khaled in the Department of Pathology, shows that mammary glands use the same cytokine molecules to illicit a reproductive response in milk-producing cells located in the breast.

The breast employs 'Type 2 T helper' cytokines, usually associated with repelling parasites, to signal resting duct cells to begin dividing and differentiating to produce large numbers of milksecreting cells.

The study was able to conclusively demonstrate the findings in a mouse model, showing that that without the presence of Type two cytokines, growth of milk-producing cells reduced markedly.

Dr Walid Khaled said: "This really was an unexpected discovery. Up until now we thought that breast development was controlled by just steroid and peptide hormones."

The discovery has also prompted the idea that a misinterpretation of the chemical signals telling cells to multiply could create cancerous growth.

"The discovery of this role played by aspects of the immune system will open up new avenues for examining the development of breast cancer, particularly in women who have just had a baby, a time when there is a greater risk of breast cancer," said Dr Khaled.

Dr Khaled also said that the findings had prompted new studies looking at the link between this chemical signaling system and cancer in other parts of the body.

"It is vital that we understand the processes involved as it is when these normal developmental events go wrong that we are at risk of cancer developing," said Dr Christine Watson, who leads the research group at the University of Cambridge.