Grant: Project Grant

Recent research progress has made many types of cancer curable. This development led to a new situation where the post-cancer quality of life became a significant concern for cancer patients. Preservation of the ability to have children draws a particular interest in the patients and their families. For male patients, the only approach to protect their fertility is currently sperm banking. This approach, however, is not applicable to boys before puberty. Thus, childhood cancer patients face a significant risk of infertility, long before they are ready to make decisions about childbearing and household formation, which also places burdens on their parents and their future partners. An emerging concept of therapeutic approach to this problem is based on sperm-making stem cells. These cells continuously produce millions of sperm everyday throughout life after puberty. Although sperm production is not fully functional in prepubertal boys, these sperm-producing stem cells do exist from the time of birth. Thus, these cells can be harvested and freeze-stored before cancer therapy, and transplanted back to the patients afterwards when they are ready to form a family. This scheme has been feasible and routinely operational in mice. This year, the first clinical trial of male fertility restoration for boys who survived childhood cancers and freeze-stored their testis tissues over a decade ago was done. We now live in an exciting time to make this approach closer to routine. However, as seen in any novel techniques, this strategy of male fertility restoration is not without limitations. The proposed study addresses three limitations to establish this new technology: to isolate human sperm-producing stem cells; to propagate these cells in test dishes; and to purge cancer cells from testis biopsies to avoid reintroduction of cancer to cancer survivors.