Male fertility can be restored after chemotherapy
Many antitumor drugs selectively destroy rapidly dividing cells. Since in the conditions of the body, malignant cells cannot be distinguished from other cells whose vital activity implies active division, the unintended victims of chemotherapy inevitably become the progenitor cells of spermatogenesis. This leads to irreversible infertility of male patients who have undergone chemotherapy.
A possible solution to the problem for mature men who plan to have offspring after the end of treatment is to store sperm in a cryobank. Unfortunately, this option is unacceptable for boys who have not reached puberty. However, even very young boys have spermatogonia in their seminal glands – stem cells that begin to produce spermatozoa during puberty.
Researchers from the University of Pittsburgh School of Medicine, working under the guidance of Dr. Kyle Orwig, decided to test whether it is possible to restore lost fertility with the help of these cells. To do this, they took biopsies of the seminal gland tissue of male macaques who had reached and had not reached puberty, and placed them in liquid nitrogen for storage. After that, the monkeys underwent a course of chemotherapy, the side effect of which is the loss of fertility.
A few months after the end of therapy, their own spermatogonial stem cells were injected into the seminal glands of the animals under ultrasound control. As a result, spermatogenesis was restored in 9 out of 12 adult males and started functioning in 3 out of 5 young males after they reached puberty.
In another experiment, sperm cells from donor monkeys were injected into 6 infertile males. As a result, chimerism (simultaneous content of donor and recipient cells in sperm) was formed in 2 out of 6 animals. Artificial insemination of 85 eggs with the sperm of one of the males with proven chimerism of spermatozoa led to the formation of 81 embryos that successfully reached the stages of morula or blastocyst. Donor origin was confirmed for 7 out of 81 embryos.
The results obtained are very promising, since some specialized centers in the USA and other countries already cryopreservate samples of seminal gland tissue of pediatric patients before starting chemotherapy. This is done in the hope that in the future new methods of cell therapy will allow them to have their own biological children.
According to Dr. Orvig, many questions remain open. Should spermatogonial cells be injected immediately after the end of therapy, or does it make sense to wait for confirmation of the patient's cure from cancer, or even the moment when he will be ready to start a family? How can the risk of cancer recurrence be eliminated, since the patient's own untreated biological material may contain malignant cells? These and other issues need to be carefully worked out, but the success of the first experimental attempt inspires great hopes.
Articles by Hermann et al. Spermatogonial stem cell transplantation into Rhesus tests regenerates spermatogenesis producing functional sperm and Firlej et al. Stem Cell Therapy for Male Infertility Takes a Step Forward published in the journal Cell Stem Cell.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on the materials of the University of Pittsburgh Schools of the Health Sciences:
Male Fertility Can Be Restored After Cancer Treatment, Says Pitt Team.
06.11.2012