Understanding the role of bacteria in prostate cancer

Queen's University BelfastDr Andrew MacDowell£157,9432009 - 2012

Why we funded it

Recent studies have shown that P. acnes is the most common bacterium found in prostate cancer tissue, and that it is significantly associated with prostate inflammation. This is an important observation because current research suggests chronic inflammation may be important in the development of prostate tumours. Determining whether this bacterium is a cause of prostate cancer will have important implications for the development of future treatments and disease prevention strategies.

 

Scientific title

Understanding the role of Propionibacterium acnes in the aetiology of prostate cancer

 

Research project summary

In this study, Dr McDowell and his team propose to confirm that a common skin bacterium associated with acne, called Propionibacterium acnes, is present in the prostate gland of patients with prostate cancer where it could establish a long-standing infection that may lead to cancer. They also propose to demonstrate how the microbe could stimulate cancerous changes to develop in prostate cells.

The team will use novel antibodies to visualise P. acnes in prostate tissue removed from patients with prostate cancer, and also grow the bacteria and use DNA-based methods for detection to identify it. These studies are the first in the United Kingdom to investigate prostate cancer tissue for the presence of the infecting microbe. The team will investigate how the bacterium could cause cancerous changes by conducting experiments with immune cells, as well as normal and cancerous prostate cells, grown in the laboratory. The cells will be stimulated with different types of P. acnes bacteria to study any effects which may be important in cancer development.

The discovery that P. acnes is a common cause of many prostate cancers would be a very exciting and major breakthrough. It could lead to the early screening of men for this new risk-factor and the use of treatments, such as antibiotic therapy, to eradicate the organism before cancerous changes develop. This would make a significant difference to the lives of men by helping to reduce the incidence of this disease. Research programmes on other conditions have focused on development of P. acnes vaccines, and their progress could become relevant for prostate cancer if P. acnes is proven to be an important risk-factor.

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More info...

Recent studies have shown that P. acnes is the most common bacterium found in prostate cancer tissue where it is significantly associated with inflammation. Current research suggests chronic inflammation may be important in the development of prostate tumours. Within the prostate, P. acnes has been found inside cells and also as large groups of aggregated bacteria, characteristics that provide strong evidence that the bacterium causes a persistent or chronic infection.

Further evidence to support this view has been the actual observation of P. acnes in sequential prostate tissue samples taken from the same patient many years apart. This ability to persist for a long period of time within the prostate may reflect the microbe's ability to resist degradation by cells of the body's immune system. It is also noteworthy that the inflammation processes that develop in acne have many parallels with the type of inflammation commonly observed in the prostate gland, and also that two large studies have found a significant correlation between a history of acne and an increased risk of developing prostate cancer.

It is expected that we will be able to confirm the presence of P. acnes in prostate cancer tissue and also to estimate the extent to which prostate cancer patients living in Northern Ireland are infected with the bacterium. We also expect to demonstrate the degree to which the bacterium can stimulate biological chemicals that could cause cancerous changes.