The Proliferation of Pre-Pubertal Porcine Spermatogonia in Stirred Suspension Bioreactors Is Partially Mediated by the Wnt/β-Catenin Pathway

Male survivors of childhood cancer are at risk of suffering from infertility in adulthood because of gonadotoxic chemotherapies. For adult men, sperm collection and preservation are routine procedures prior to treatment; however, this is not an option for pre-pubertal children. From young boys, a small biopsy may be taken before chemotherapy, and spermatogonia may be propagated in vitro for future transplantation to restore fertility. A robust system that allows for scalable expansion of spermatogonia within a controlled environment is therefore required. Stirred suspension culture has been applied to different types of stem cells but has so far not been explored for spermatogonia. Here, we report that pre-pubertal porcine spermatogonia proliferate more in bioreactor suspension culture, compared with static culture. Interestingly, oxygen tension provides an avenue to modulate spermatogonia status, with culture under 10% oxygen retaining a more undifferentiated state and reducing proliferation in comparison with the conventional approach of culturing under ambient oxygen levels. Spermatogonia grown in bioreactors upregulate the Wnt/ β-catenin pathway, which, along with enhanced gas and nutrient exchange observed in bioreactor culture, may synergistically account for higher spermatogonia proliferation. Therefore, stirred suspension bioreactors provide novel platforms to culture spermatogonia in a scalable manner and with minimal handling.

National Cancer Institute's Cancer and Aging Priorities

Modern improvements in cancer detection and treatment coupled with the implementation of population-based cancer prevention and control strategies have contributed to a sustained decline in overall cancer mortality rates. Although this trend is promising, challenges at the nexus of cancer and aging are, in turn, becoming more prominent. Older adults (age 65 years and older) are the largest growing segment of the U.S. population, and aging into older adulthood is disproportionally associated with the incidence of common cancers. Many survivors of childhood cancer will live for decades after cancer treatment and mature into older age. Strategic investments in aging research will contribute to population health by preserving or improving healthspan and ensuring equitable access to – and benefit from – advances in cancer prevention, control, and population science. This presentation will describe ongoing cancer and aging efforts at the National Cancer Institute, including programmatic priorities and current funding opportunities.

Endocrinology aspects of other clinical or physiological situations

This chapter covers endocrine aspects of a variety of conditions and situations. It explains the symptoms and investigations of hypoglycaemia along with its management; mastocytosis, cancer and the associated endocrine sequalae of survivors of childhood cancer, syndromes of ectopic hormone production, and associated disorders. It then covers the effects on endocrinology on liver and renal diseases, and in the critically ill. Differential diagnosis of endocrine disorders is outlined, alongside the effects of stress and exercise on the endocrine system. Finally, alternative therapies are discussed.