Human feeder layer system derived from umbilical cord stromal cells for human embryonic stem cells

Objective: To evaluate the potential of human umbilical cord-derived stromal cells (hUCSCs) as a human feeder for human embryonic stem cells (ESCs). Design: Prospective study. Setting: Laboratory of Molecular Genetics and Stem Cell Differentiation, Dental Research Institute, School of Dentistry, Seoul National University. Intervention(s): The hUCSCs were established, and human ESCs were cultured on established hUCSCs without serum. Main Outcome Measure(s): Cell-surface markers, karyotyping, and teratoma formation. Result(s): Primary cultures of hUCSCs from individual umbilical cords were maintained by an established protocol. Human ESCs on hUCSC layers were successfully maintained in serum-free culture medium past passage 30. Compared with hESCs on mouse feeder cells, the hESCs on hUCSCs showed similar levels of pluripotency-related cell-surface markers, self-renewal capacity, and teratoma formation in immune-deficient mice. These ESCs cultured on hUCSCs had a normal karyotype, even after long-term culture. Conclusion(s): The hUCSCs supported self-renewal of hESCs in serum-free conditions. This culture system has the potential to facilitate the development of clinical-grade hESCs for regenerative medicine. (Fertil Steril (R) 2010; 93: 2525-31. (C) 2010 by American Society for Reproductive Medicine.)