Fat cells release a specific protein that plays a key role in advancing prostate cancer in mice, reports a study published in Nature Communications. This newly-discovered mechanism adds support to the idea that obesity influences the aggressiveness of prostate cancer, and may also facilitate the development of alternative therapeutic strategies for this disease.

Increasing evidence supports the association of obesity with a greater risk of aggressive prostate cancer. However, the underlying mechanisms have been unclear up to now.

Catherine Muller and colleagues show that cultured mouse and human fat cells secrete a protein called CCL7, which binds to a specific receptor, called CCR3, expressed by prostate cancer cells, and that this bond initiates cancer cell migration and dissemination. They then study around 40 mice - some on a high fat diet and others on a normal diet - and find that local invasion of prostate cancer cells is enhanced in obese mice due to the presence of more fat tissue. They also show that expression of the CCR3 receptor in human prostate cancer tumours from tissue samples is associated with an aggressive form of the disease and migration of cancer cells outside the prostate gland in the surrounding fat tissue.

The authors propose that these results in mice could be used in the future to develop drugs to treat prostate cancer in human patients.