Researchers at the University of Southern California have successfully grown human, testosterone-producing cells in the lab, paving the way to someday treat low testosterone with personalized replacement cells.
In the Proceedings from the National Academy of Sciences, scientists describe how they transformed stem cells into functioning Leydig cells—the cells in the testes that produce the male sex hormone.
“Our study provides a way to generate possible transplantation materials for clinical therapies, as well as a path toward testing and developing new drugs,” says Vassilios Papadopoulos, dean of the USC School of Pharmacy, who led the research.
Millions of men have low testosterone, or hypogonadism, which impacts mood, fertility, sexual function, obesity and bone density. And testosterone replacement therapy is a multibillion-dollar industry. Testosterone tapers off naturally with age but can also decrease suddenly due infections like mumps, or cancer treatment during childhood.
Testosterone replacement therapy—injected, taken orally or applied as a gel—reverses many of these symptoms. “You feel better, you lose weight, erectile function returns,” Papadopoulos says. “Men love testosterone.” However, treatment for “low T” is linked to side effects such as infertility, increased risk of prostate cancer and cardiovascular diseases. In addition, topical treatments can rub off on close contacts, inadvertently exposing others to the drug. A transplant of lab-grown testosterone-producing cells, perhaps injected into fatty tissue, could potentially bypass those side effects, researchers say.
However, human transplantation of Leydig cells is at least “a few years away,” he says.