A University of Texas at San Antonio professor has demonstrated a new procedure that could restore fertility to people who must undergo radiation and chemotherapy treatments for cancer.
UTSA Assistant Professor Brian Hermann worked in collaboration with researchers at the University of Pittsburgh School of Medicine’s Magee-Womens Research Institute (MWRI) to develop a technique he came up with during his post-doctoral studies.
The treatment involved the removal of testicular stem cells from a monkey prior to chemotherapy. The stem cells were then frozen and stored until after the cancer treatments, at which time they were transplanted into the monkey to restart sperm production and restore fertility.
The results of the study were published last month in Cell Stem Cell, a leading journal in stem cell biology. Hermann’s research is funded by a $3.5 million grant from the Eunice Kennedy Shriver National Institute of Child Health and Human Development.
“This is a really exciting milestone for this research,” says John McCarrey, director of the San Antonio Cellular Therapeutics Institute. “This is the first time that anybody has been able to show the concept works in a primate model, and that is an important step in moving the research forward to clinical trials.”
The research is particularly significant for young boys facing cancer treatments. While men are able to store their own sperm for future use in the fertility clinic, this is not an option for boys before puberty who are not yet making sperm. But, all prepubertal boys have spermatogonial stem cells (SSCs) in their testes, which could be used for transplantation.
Research hurdles
The research must still overcome a number of hurdles before it can become a common clinical practice, however.
“This research demonstrates the proof of principle — that the concept works in primates and has a good chance of working in humans,” Hermann says. “We need to better understand the optimal timing of transplantation, how to prepare testicular stem cells for transplantation and make them safe for transplantation, and how to maximize their ability to restart sperm production.”
Hermann says one key concern is making sure that transplanting the stem cells does not reintroduce the cancer. It would not be acceptable to risk the life of the patient for this kind of therapy, Hermann says. But there are also many non-cancer patients who could benefit from the procedure, including those undergoing bone marrow transplants for immune deficiencies and other problems.
“We could work with some of the non-cancer patients first to establish that it is a viable procedure,” Hermann says. “There are currently only a handful of clinics around the world that will remove and preserve testicular stem cell samples from prepubertal patients, and that limits the availability of candidates. Until more clinics get on board and save stem cells for patients, we are limited in what we can do to test transplantation in clinical trials.”
Hermann says he has not looked into the commercialization possibilities for the therapy yet because there is still much work that needs to be done first. “We need to have more information on the efficacy in humans, but this is a big step forward,” he says.
Hermann says he has no doubt the market is there once the therapy is ready because people are already signing up to be tissue donors. But until now, the technology has only worked in very small mammals, so succesffully demonstrating its use in primates is a big deal.
If the research is successful, it could also prove to be beneficial in other areas were transplanting stem cells may help patients with neuro-degenerative diseases and other health problems, Hermann adds.
Hermann joined the UTSA College of Sciences’ faculty in summer 2011, following a post-doctoral fellowship at MWRI alongside Associate Professor Kyle Orwig. At UTSA, he is continuing to focus his research on basic and translational studies of spermatogonial stem cells to preserve fertility in boys treated for cancer and related diseases.
“For a long time, oncologists have been unable to address the long-term consequences of life-saving chemotherapy and radiation treatments such as infertility,” Hermann says. “That is now beginning to change as laboratory research such as this study provides new experimental options for patients facing infertility after cancer.”
Hermann says he is hopeful that within the next five years the country will see its first human patients benefitting from this procedure. In the meantime, he plans to do more collaborative work with researchers around the country as well as in San Antonio.
He notes that the University of Texas Health Science Center at San Antonio has good infertility infrastructure in place where a lab and clinic could be set up.
To learn more about Hermann’s research, visit http://hermannlab.utsa.edu.