NEW YORK, Dec 27 (Reuters Health) -- A new technique, in which immature
sperm cells in mice are encouraged to develop into functioning sperm, might
someday restore fertility to human males, according to a report in the January
issue of Nature Medicine.
In a study, researchers collected immature sperm cells, known as germ stem
cells, from infertile mice, then transplanted them into the testes of a
different strain of infertile mice.
Eighty percent of the recipient mice began to produce normal sperm, the
research team observed. Four out of nine male mice that mated with normal female
mice were successful in reproducing.
"The possibility of obtaining offspring from males with (few or no sperm)
has improved considerably with the development of assisted reproductive
techniques, and testis cell transplantation should allow additional progress in
this area," according to study author Dr. Ralph Brinster and his team, from the
University of Pennsylvania School of Veterinary Medicine in Philadelphia.
The technique may be useful in treating childhood cancer survivors, who
are at risk for infertility due to cancer treatments, according to an
accompanying article by Dr. Howard Cooke, from Western General Hospital, and Dr.
Philippa Saunders, from the MRC Reproductive Biology Unit, both in Edinburgh,
Scotland.
While adult cancer patients can have sperm frozen before undergoing a
fertility-damaging treatment, this is not an option for boys who have not yet
gone through puberty, Cooke and Saunders note. They suggest that prior to
therapy, germ stem cells could be collected and frozen. Once the testicular
environment has recovered, the germ stem cells could be transplanted back to the
patient.
In most cases, the cause of infertility is unknown. However, Brinster's
team concludes that the new study has shed light on the process of sperm
development and may someday result in a practical therapy for male infertility.
