Researchers at Genentech, in San Francisco, found that the prostate contains adult stem cells that are capable of building a new prostate gland.

In mice, the researchers were able to reconstitute an entire prostate gland from prostate stem cells. Wei-Qiang Gao, PhD, and colleagues at Genentech Inc., South San Francisco, say the same king of cells can be found in humans.

Gao’s team extracted some key cells from adult mouse prostate glands and cultured them in the laboratory. The cells were grafted on to a mouse kidney, where they developed into a full-sized prostate gland in just a few weeks. The study demonstrates the capacity of a single cell to develop into en entire organ.

A stem cell is generally characterized by the presence of various cell markers on its surface. Three markers had previously been associated with stem cells in the prostate. Genentech researchers discovered an additional marker, called CD117. They found the same marker seen in mouse stem cells in human adult prostate stem cells.

“CD117 prostate stem cells can generate functional, secretion-producing prostates when transplanted,” Gao and colleagues wrote in their report, published on Wednesday in the journal Nature.  “This is, to our knowledge, the first report to demonstrate prostate generation from a single adult stem cell,” they added.

The study’s authors say that the identification of single cells capable of generating an entire organ “has important implications for tissue repair and regrowth” and it could provide insight into how the disease develops. Learning more about this process could lead to new ways of fighting the disease.

Adult stem cells, one of the three main types of stem cells, are found throughout the body after embryonic development and they divide to replace dying cells and regenerate damaged tissue. Other two types of stem cells are embryonic stem cells that are found in blastocyst (an early stage embryo) and induced pluripotent stem cells, also called iPS cells that are derived from an adult somatic cell using genes and viruses.

If the new method can be applied to human cells, it may offer a safer way to examine the process involved in the development of prostate cancer in its earlier stages and to see how this cell population helps regulate growth in the prostate. Theoretically, the new method could be used to grow replacement prostate glands for men who underwent surgeries to remove their glands as part of their cancer treatment.

Prostate cancer is the ninth most common cancer worldwide, but is the number one non-skin cancer among American men. It seems that this type of cancer affected 18% of United States men and led to death of 3% in 2005 only. According to the estimates of the American Cancer Society (ACS), about 186,000 men will be diagnosed with prostate cancer by the end of this year. Almost 28,000 men loose the battle with the disease each year.