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.