Stem cells found in men's testicles could someday be used to grow organs and tissues needed to fight disease, researchers at the Weill Cornell Medical College in New York City have found.

Their findings are to be published in Thursday's issue of Nature.

During the study, scientists also discovered that the spermatogonial progenitor stem cells expressed a marker or cellular identifier called GPR125, making the highly specific cells more easily distinguishable.
(Associated Press)

Scientists obtained spermatogonial progenitor stem cells (SPCs), which generate the precursors to sperm and determine fertility, from mouse testicles.

These cells were allowed to "soak" in their specially designed cell culture conditions and gradually transformed into "multi-potent adult spermatological-derived stem cells," which are transmutable, meaning they can morph into other types of cells in the body.

These cells were then transplanted back under the skin of mice and developed into functional blood vessels, cardiac cells and brain cells.

During the study, scientists also discovered that the spermatogonial progenitor stem cells expressed a marker or cellular identifier called GPR125, making the highly specific cells more easily distinguishable.

"One problem with working with SPCs is that they've been extremely difficult to identify. We discovered that, within the testicular environment, only SPCs express a particular marker called GPR125," said Dr. Marco Seandel, a researcher at the Howard Hughes Medical Institute and researcher-medical oncology fellow at Memorial Sloan-Kettering Cancer Center in New York City.

"That's a quantum leap forward in terms of being able to harvest and work with these cells."

Human studies still needed

Research conducted by other researchers has shown that adult cells can be reprogrammed to acquire stem-cell potential. However, this process, called "induced pluripotency," has resulted in a generation of multi-potent stem cells that carried an increased risk of transforming into malignant cells.

"What's really novel about our work is that — unlike induced pluripotency — these mouse SPCs do not require any addition or tweaking of genes to get them to form the multi-potent cells that then go on to produce all of these cell types," notes senior author Dr. Shahin Rafii, Arthur Belfer professor of genetic medicine and director of the Ansary Stem Cell Center for Regenerative Medicine at Weill Cornell Medical College.

He said the "switch" that would allow researchers to control the stem-cell transformation process on demand has not yet been discovered. And he warned that human studies are needed before testicular cells become an alternative source of stem cells.

"Nevertheless, it appears that these unique specialized spermatogonial cells could be an easily obtained and manipulated source of stem cells with exactly the same capability to form new tissues that we see in embryonic stem cells," said Rafii.

The researchers hope the findings of the study will eventually lead to the regeneration of organs in people with heart disease, Alzheimer's, Parkinson's, stroke, diabetes and other medical conditions.