When post-pubescent males undergo anti-cancer treatments that have the potential to render them infertile, they have the option of preserving some of their sperm beforehand and having it kept frozen until a time in the future if or when they decide they want it.
The same option is not available to pre-pubescent males who undergo anti-cancer treatments designed to save their lives but that also put their future fertility at great risk. But now there may be a way to do preserve their fertility, thanks to researchers at the University of Pennsylvania School of Veterinary Medicine. Yes, veterinary medicine.
Fertility in males is a function of spermatogonial stem cells. They exist from birth and are found within the siminiferous tubules of the testes. At or near puberty, these stem cells start to create the cells that will become sperm. Unfortunately, for very young cancer patients, radiotherapy and chemotherapy can kill the stem cells, rendering many boys infertile before they ever had a chance at fertility.
Some hospitals and cancer centers have begun to freeze these stem cells in the hopes that future technology would be able to find a way to re-introduce them into the individual when he is of-age, but nobody knew whether the cells would even survive freezing for that long, or whether they would work once implanted. That's where the vet researchers come in.
Their findings have appeared in Human Reproduction, indicate that, at least in the mice whose spermatogonial stem cells they froze in the 1990s, not only do they survive the deep freeze, they also know where to go once implanted in mice--meaning they migrated to the testes and embedded themselves in the right place--and they can generate active sperm. They know this last aspect because they used some of the newly created and extracted sperm to successfully fertilize eggs in the lab, and because one of the male mice, when put with females, successfully fathered offspring.
Source: Medical News Today