The tissues of the prostate, a gland in the male reproductive system, generate aberrant cells in prostate cancer. In older men, prostate cancer is more prevalent.
For men with advanced prostate cancer, hormone therapy is the go-to treatment. Androgens from sex, such as testosterone, can promote the growth of prostate cancer.
To limit or prevent the action of androgens during treatment, physicians may utilize medications, surgery, or other hormones.
Androgens are hormones that promote the growth of prostate cells; their removal through medication or surgery results in a 90% reduction in prostate size.
Even so, the tumor can eventually come back, and when it does, it normally won’t respond to more hormone therapy. Another risk is that it will spread to other organs.
Revelations Made From New Studies
A recent study from Memorial Sloan Kettering researchers sheds light on how the prostate can recover so quickly. And it’s not what the scientists had predicted at first.
The Broad Institute’s Drs. Charles Sawyers and Aviv Regev studied how healthy prostate tissue regenerates following androgen deprivation therapy.
The National Cancer Institute (NCI) of the NIH provided some funding for the research. Science published the findings on May 1st, 2020.
A limited population of stem cells that are in charge of rebuilding the gland was what was generally anticipated.
Instead, almost every cell that survived following hormone deprivation therapy helped the prostate gland regenerate.
The Cellular Structure Of The Prostate Gland
Single-cell RNA sequencing (scRNA seq), a potent tool, assisted the researchers in making their discovery.
With the help of this type of analysis, researchers may determine which genes are active simultaneously in a large number of different tissue cells.
The study team carried out scRNA seq on roughly 14,000 cells in the mouse prostate gland. Using these data, they could completely map out the cell types present in a typical mouse prostate.
With this knowledge, the researchers could later identify which cell types remained in the prostate after the mice underwent androgen deprivation therapy and which divided to repopulate the gland after androgen was reintroduced.
These studies showed that almost all of the prostate’s luminal cells were dividing, as opposed to just a small portion, as would be predicted if the gland’s regeneration was mostly the result of a stem cell population.
Additionally, it was evident that the luminal cells, which normally produce fluids, had developed skills that they would not typically possess in an animal with intact hormones.
In addition to their animal studies, the researchers used prostate tissue from men who had undergone treatment for prostate cancer to do scRNA seq.
Similar patterns of luminal prostate cells with stem cell characteristics were discovered. This suggests that what is accurate for mice may also be accurate for people.
Contradictions With Existing Theories
The study’s results defy a conventional theory of how stem cells renew and mend tissue.
According to this theory, stem cells are a unique and distinctive sort of cell that may give rise to a variety of cell types while still having the ability to increase.
However, recent research, including this one, has questioned how broadly applicable this concept is to many organs.
This study demonstrates that fully differentiated cells can develop into stem cells, at least in the prostate.
Previous research revealed that some prostate cancer cells can change who they are.
For instance, they can rewire themselves to develop into a specific kind of prostate cell that does not require androgen to thrive. The term for this is lineage plasticity.
Prostate cancer cells eventually become resistant to hormone-blocking treatments partly because of lineage plasticity.
Conclusions Of The Research
The researchers examined prostate tissue from humans after reaching new conclusions from the tissue of mice.
Similar luminal populations were found in samples from men with prostate cancer who had undergone androgen deprivation therapy.
Androgen deprivation therapy could have positive and negative effects. Many cells die, but those that survive have this stem-like characteristic.
The results imply that differentiated and stem-like luminal cells, rather than merely a small number of stem cells, may be responsible for prostate regeneration after hormone therapy.
Improved prostate cancer treatment may result from knowing how luminal cells have this increased capacity to renew. There may be important ramifications for treatment, but the most recent findings are unclear.