Restoring Fertility in Sterile Childhood Cancer Survivors by Autotransplanting Spermatogonial Stem Cells: Are We There Yet?

Table 1

Selected milestones in the history of spermatogonial stem cell research.

Year	Author	Highlighted findings	Species	References
1966	Clermont	Initial histological description of Apale and Adark spermatogonia	Human	[35]
1971	Huckins	Model for renewal and differentiation of spermatogonia and existence of “spermatogonial stem cells” (SSCs)	Rat	[36]
1994	Brinster and Avarbock	First successful transplantation of testis-derived cells from one mouse to another resulting in donor-derived F1 progeny	Mouse	[18]
1998	Nagano et al.	In vitro maintenance of SSCs for 4 months on a somatic feeder layer	Mouse	[37]
1999	Schlatt et al.	Xenotransplantation of primate testis cell suspensions from one primate into the testes of another	Macaque	[23]
2002	Nagano et al.	First report on successful colonization of mouse testes after xenotransplanting human SSCs	Human	[38]
2003	Kanatsu-Shinohara et al.	Prolonged in vitro propagation of SSCs using GDNF, without immortalization of the cells in culture	Mouse	[29]
2005	Keros et al.	Proof of successful cryopreservation of testicular biopsies without decreasing structural integrity	Human	[39]
2005	Kanatsu-Shinohara et al.	Long-term propagation of SSCs under serum free and feeder free conditions	Mouse	[40]
2009	Sadri-Ardekani et al.	Long-term propagation of adult SSCs in vitro with retainment of functionality	Human	[31]
2011	Sadri-Ardekani et al.	Long-term propagation of prepubertal SSCs with retainment of functionality	Human	[30]
2012	Hermann et al.	Production of functional sperm by infertile prepubertal macaques after autotransplantation, capable of fertilizing oocytes	Macaque	[21]