PROSTATES of older mice have been found to contain a higher quantity of luminal progenitor cells, which generate new prostate tissue, than of younger mice. Research carried out by a team at UCLA explains why the prostate organ grows as men age, which increases the risk of a number of conditions, including prostate cancer.
As people age, their organs, such as the kidneys and liver, tend to lose mass, along with bone and muscle mass decreasing over time. However, the prostate tends to grow over time, resulting in >50% of men experiencing benign prostate hyperplasia: enlarged prostate impacting the urethra. Previous research has demonstrated that progenitor cells are diminished in number in organs that have shrunk with age.
“Understanding what’s causing the prostate to grow with age helps us to consider strategies to prevent the expansion of these cells and possibly reduce a person’s risk for prostate growth or disease,” explained researcher Andrew Goldstein, member of the Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research at UCLA, California, USA.
The researchers studied the prostates from two groups of mice: 3-month-old mice, equivalent to young adult humans, and 24-month-old mice, representing 80-year-old humans. When comparing the prostates, they found that the older group had heavier and larger prostates and had a higher level of luminal progenitor cells.
“We thought it was a real possibility that older cells would have a reduced capacity to generate prostate tissue when we took them out of the prostate, so it was a surprising and important finding that there’s really no difference between old cells and young cells in their ability to form prostate tissue,” continued Goldstein.
These cells were then isolated and grown to create prostate organoids. Luminal cells from the older animals were able to form organoids just as effectively as those from the younger group, and the older organoids were typically even larger than those from the younger mice. Results showed that only 6% of the luminal prostate cells found in younger mice were progenitors, compared to 21% in older mice. This, combined with ability to still form new tissue, offers an explanation as to why the prostate grows as men age, bringing with it the increased risk of prostate cancer and benign prostatic hyperplasia.