For parents of 130 boys on average each year in Canada, a terrifying diagnosis of testicular cancer is only the start of their worries. Treating the cancer—while life saving—can result in permanent infertility. That’s because the side effects of chemotherapy or irradiation treatments can sometimes damage “germline stem cells,” scarce stem cells that produce sperm.
Reproducing these special stem cells using currently available therapies has proved challenging for medical scientists.
But a USask research team has significantly improved a technique for preserving and replicating germline stem cells from newborn animal testes. The hope is that the technique may one day be able to help restore boys’ fertility by taking testes tissue samples and freezing them to later produce germline stem cells.
The research, led by USask PhD graduate Awang Hazmi Awang-Junaidi, has been published in Reproduction, Fertility and Development and the Journal of Animal Science and Biotechnology.
“Freezing semen from young cancer patients before they undergo treatments is usually how a boy’s future fertility is protected, but pre-teen boys do not produce sperm so there’s nothing to freeze. Our technique could solve this problem,” said USask veterinary biomedical sciences professor Ali Honaramooz, Awang-Junaidi’s supervisor.
“Our technique could also help save species at risk of extinction and help valuable livestock reproduce.”
Early results on mice using the USask technique have shown that germline stem cells taken from piglets successfully regenerate pig testes tissue in about two weeks, and are also able to produce functional sperm over time. The body functions of pigs are similar to those of the human body, so pigs are a good model.
“Our new cell culture system helps increase the number of germline stem cells available and preserves them for longer—even years, which is crucial for reproduction therapies,” said Awang-Junaidi, now a veterinary senior lecturer at Universiti Putra Malaysia.
“We found that the younger the piglet donor, the better their testes cells had potential for producing new tissue,” he said. “Knowing this, we can estimate that for human applications a similar procedure would work best in boys and teenagers.”
While the USask results are promising, more research has to be done before applying the technique to humans, Honaramooz cautions. The research is funded by the federal agency NSERC.
Germline stem cells may also have the potential to become any type of tissue in the body, unlocking a possible new source for future stem cell therapies, Honaramooz said.
The USask team’s novel method for culturing germline stem cells has also shown that these cells display features similar to embryonic stem cells. The researchers add, however, that more work is needed to prove the cells’ potential.
The researchers also plan to study how environmental toxins may affect the ability of germline stem cells to treat infertility.
“The increase in human testicular cancer is thought to be linked to an increase in toxic substances in the environment, so a next step of this research involves toxicological studies to determine how the germline stem cells are affected,” said Honaramooz.
Federica Giannelli is a CGPS-sponsored graduate student intern in the USask research profile and impact unit.
This article first ran as part of the 2020 Young Innovators series, an initiative of the USask Research Profile and Impact office in partnership with the Saskatoon StarPhoenix.
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