Prostate gland grown from a single stem cell

Researchers in the US have reported growing a new prostate gland in mice transplanted with a single stem cell. It is hoped that the finding will shed new light on the development of prostate cancer.

The prostate is a gland found near the bladder in males, which aids semen production. In older men, it can become inflamed and have serious medical implications, including cancer. Every year 10,000 men die from prostate cancer in the UK, with a quarter of all new cancers diagnosed in men being prostate cancer.

The team of scientists at Genentech Inc in San Francisco first discovered a protein on the cell surface of the prostate stem cells, named CD117, which enabled their identification. The markers used previously were also found on other cell types, making differentiation of these particular cells difficult. Using this protein, they isolated the stem cell responsible for the growth of the gland and, to confirm its identity, transplanted it back into the kidney of the mouse. Within eight weeks, the researchers noted characteristic prostate tissue architecture and were able to measure secretion of specific prostate chemical markers in 14 of 97 single cell transplants.

The results, reported in the journal Nature, will help scientists examine how these specific stem cells regulate growth in the prostate, and also investigate any contribution they may have in the progression of prostate cancer. Many scientists believe that stem cells in normal tissue are involved in the development of cancer due to their ability to self-regulate growth.

Leisa Johnson, a molecular biologist at Genentech and co-author of the study, has mentioned further implications for the work, saying that 'if the CD117 cell population does lead to tumour initiation or cancer recurrence, this cell marker could become a therapeutic target'.

Any hopes for the discovery to be used for regeneration of prostate glands to replace those removed in cancer have been repressed, however, by speculation that the benefits of older men having the gland would not justify the procedure. Complex surgery would also be required to reconnect the gland to the urethra and the nerve system controlling its activity.

John Neate, the chief executive of The Prostate Cancer Charity, said that the work was 'an important piece in the jigsaw of our understanding of the role that stem cells play in the prostate' and the development of cancer.