Skip to main content
Accessibility|Contact|Privacy|Terms of Service

Testes Stem Cells can Change into Other Body Tissues

  • Published: 2009-01-14 (Revised/Updated 2010-07-11) : Author: Stanford University School of Medicine
  • Synopsis: Scientists isolated stem cells from human testes that differentiate into the three main types of tissues of the body.

Main Document

Scientists at the Stanford University School of Medicine The Turek Clinic in San Francisco have succeeded in isolating stem cells from human testes.

The cells bear a striking resemblance to embryonic stem cells - they can differentiate into each of the three main types of tissues of the body - but the researchers caution against viewing them as one and the same.

According to the study, the testes stem cells have different patterns of gene expression and regulation and they do not proliferate and differentiate as aggressively as human embryonic stem cells.

The findings, published in the January issue of the journal Stem Cells, are in contrast to those reported in a recent Nature paper, which concluded that the cells were, in fact, as pluripotent as embryonic stem cells. Pluripotent cells can become any cell in the body and form tumors called teratomas when transplanted into mice.

"It's time to reinterpret the data," said Renee Reijo-Pera, PhD, professor of obstetrics & gynecology at Stanford, "and to accept that we're beginning to discover many different types of stem cells. Although they are all related to each other, they also all have unique therapeutic applications in which they surpass other family members."

Reijo-Pera, who is the director of Stanford's Center for Human Embryonic Stem Cell Research and Education, collaborated with male infertility specialist Paul Turek, MD, director of The Turek Clinic in San Francisco, to conduct the research. Reijo-Pera and Turek are co-senior authors of the study.

The stem cells from the testes seem to hover in a gray area between true pluripotency and the more limited, tissue-specific multi-potency exhibited by many types of adult stem cells. They termed the cells "multi-potent germline stem cells." Germ cells are those cells in the body that differentiate to make sperm and eggs.

Playing to these cells' strengths - in this case, their likely ability to differentiate into cells involved in male reproduction - may be a wiser choice than trying to pigeonhole them as embryonic-stem-cell-wannabes, said Reijo-Pera.

"These cells could potentially treat infertility or other diseases in men," Turek said.

But the lure of pluripotency is strong. An easily accessible source of unmodified, pluripotent human cells would allow physicians and researchers to create cell lines and tissues identical to others in the donor's body. Theoretically such cells could be used as a perfectly matched therapy for that particular donor - perhaps to generate new cartilage to repair a knee injury or new neurons to treat nerve damage. Alternatively, the technique could be used to derive cell lines carrying specific disease-causing mutations - from a man with Parkinson's, for example-on which to conduct research.

Coaxing specialized, or differentiated, adult cells to regress back into a more malleable, embryonic-stem-cell-like state (a process called "induced pluripotency") would also allow scientists to realize the therapeutic benefits of embryonic cells without the thorny ethical problems that plague cells derived from embryos. Until recently, however, the reprogramming of differentiated cells required the use of viruses to introduce specific genes into the cells, which may limit their therapeutic usefulness.

The researchers used cells obtained via biopsies conducted to diagnose male infertility in 19 of the clinic's patients. Each patient's cells were cultured in a manner similar to human embryonic stem cells; two of the 19 samples yielded cell lines with many characteristics of the pluripotent cells. One of the two patients from whom the cell lines were derived withdrew from the study and his samples were discarded.

Further study on the remaining cell line indicated that it expressed many, but not all, genes associated with pluripotency. The cells could also be induced to differentiate into decidedly non-testicular neural cell precursors and they expressed the telomerase enzyme essential to keep pluripotent cells young and unspecialized. However, when the researchers examined the cells' patterns of methylation - a modification to DNA that affects gene expression - they found that the newly derived cell line was less-thoroughly methylated as compared to human embryonic stem cells in one region and more heavily methylated than human embryonic stem cells in another region.

Finally, when the researchers injected the human stem cells into mice with compromised immune systems, they showed only a limited ability to form a teratoma - a kind of tumor formed of many cell types. Teratoma formation resulting from the aggressive proliferation and differentiation of transplanted stem cells is a hallmark of true pluripotency. Together, the results suggest that the stem cells isolated from male testes have some, but not all the characteristics of true pluripotent cells.

"It's not yet possible to completely re-create human embryonic stem cells from germline cells," said Reijo-Pera, "These cells differ in gene expression, methylation and in their ability to form teratomas. But it's the fact that they are different that makes them so interesting. Suggesting otherwise would do a disservice to the research community by overlooking the fact that these cells are a unique cell type that could be really useful in the study of human germ cell formation."

Reference: Other Stanford collaborators on the research include graduate students Nina Kossack and Cory Nicholas; research assistant Ha Nam Nguyen; and postdoctoral scholar Shawn Chavez, PhD. The research was funded by the Gottlieb Daimler and Karl Benz Foundation, the California Institute of Regenerative Medicine and the National Institutes of Health.

Stanford University Medical Center integrates research, medical education and patient care at its three institutions - Stanford University School of Medicine, Stanford Hospital & Clinics and Lucile Packard Children's Hospital at Stanford. For more information, please visit the Web site of the medical center's Office of Communication & Public Affairs at mednews.stanford.edu

The Turek Clinic is a next-generation men's health-care medical practice specializing in issues facing men of reproductive age. The practice was founded by Paul Turek in May 2008. For more information visit www.TheTurekClinic.com

Similar Topics

1 : Smart Cells Releases 1st Sample to Treat Autism : Smart Cells.
2 : Discovery May Result in Medication to Build Stronger Muscles Even in Old Age : Karolinska Institutet.
3 : Sensory Interneurons from Stem Cells Enable the Sense of Touch : University of California - Los Angeles Health Sciences.
4 : COPD Patients See Improvement from Stem Cell Therapy : Lung Institute.
5 : Stem Cell Therapy to Relieve Joint Pain : Dr. Mark Wagner.
From our Regenerative Medicine section - Full List (94 Items)


Submit disability news, coming events, as well as assistive technology product news and reviews.


Loan Information for low income singles, families, seniors and disabled. Includes home, vehicle and personal loans.


Famous People with Disabilities - Well known people with disabilities and conditions who contributed to society.


List of awareness ribbon colors and their meaning. Also see our calendar of awareness dates.


Blood Pressure Chart - What should your blood pressure be, and information on blood group types/compatibility.





1 : Autism Prevalence Increases to 1 in 59 US Children
2 : Yelp Reviews of Nursing Homes Tend to Focus on Staff Attitudes and Responsiveness
3 : Non-Invasive Spinal Stimulation Enables Paralyzed People to Regain Use of Hands
4 : What if You Could Know Your Mild Cognitive Impairment Would Not Progress?
5 : Millennials Fail to Understand Dangers of Tanning
6 : Appetite Loss After Exercising Explained
7 : Bias Keeps Women with Higher Body Weight Away From the Doctor
8 : Smart Hoteliers are Building a Healthier Future


Disclaimer: This site does not employ and is not overseen by medical professionals. Content on Disabled World is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of a physician or other qualified health provider with any questions you may have regarding a medical condition. See our Terms of Service for more information.

Reporting Errors: Disabled World is an independent website, your assistance in reporting outdated or inaccurate information is appreciated. If you find an error please let us know.

© 2004 - 2018 Disabled World™