Thanks to modern medicine, more than 70 percent of patients survive childhood leukemia. But the side effects can be devastating as chemotherapy can often irreversibly damage the parts of the male reproductive system that produce spermatozoa, causing male infertility. Up until now, the only option for the preservation of fertility in leukemia patients was to store sperm for later use before the commencement of the chemotherapy treatment. For young leukemia sufferers however, this presents a problem, as mature cells do not develop until the onset of puberty. Consequently, young children are unable to utilize such techniques.
While research into the transplantation of the patients own germ cells after chemotherapy shows promise for restoring fertility, a major problem has been the risk of contamination by leukemia cells, which may trigger a relapse of the disease. But now, an article in the Journal of Clinical Investigation suggests a new technique, developed by researchers from Osaka University, that may solve the problem.
Akira Tsujimura and co-researchers have developed a method in which healthy germ cells, including spermatogonial stem cells, can be distinguished and completely separated from leukemia cells in mice, and then harvested and preserved. These cells were then transplanted into the gonads of healthy recipient mice previously exposed to chemotherapeutic agents. The germ cells were transplanted successfully and the mice were able to produce healthy infants.
The successful birth of offspring of recipient mice - without the transmission of leukemia - suggests that the autotransplantation of carefully sorted germ cells after anticancer treatment may be a viable method for preserving fertility in humans.
But the researchers point out that there are still a number of obstacles to overcome before the procedure is ready for humans. These include: the ability to harvest a sufficient number of healthy germ cells without significant tissue loss; ensuring the isolation of germ cells from the population of malignant cells to avoid relapse; and ensuring that isolated germ cells are able to undergo normal spermatogenesis. The researchers are upbeat however, and believe the procedure has great potential for the treatment of infertility following chemotherapy.
