Growing surplus of frozen embryos in China offers opportunities for the development of human embryonic stem cell banking

摘要

To realize the full potential of human embryonicnstem cells (hESCs) in regenerative medicine, thenmajor challenge is to overcome the immunologicalnbarrier in transplantation and transfusion therapy.nA promising approach is the banking ofnnumerous hESC lines derived from donated surplusnin vitro fertilized (IVF) embryos for subsequentnHLA-matching with patients [1]. This is anmuch more practical and economical solutionncompared with somatic cell nuclear transfern(SCNT) for the derivation of immunocompatiblenpatient-specific hESC lines [2], which is beset withnformidable technical challenges and ethical problemsnin donor oocyte procurement [3,4]. Thenabject failure of Hwang and co-workers to generateneven a single cloned hESC line, after havingnutilized more than 2000 donated humannoocytes [4], cast serious doubts on the usefulness ofnsuch research for future clinical applications [5,6].nEven if the proof-of-principle experiment fornnuclear transfer-derived hESCs is successfullynachieved sometime in the future; technical constraints,nhigh costs and the length of time that willnprobably be needed to produce adequate quantitiesnof customized therapeutic tissue by genomicnreplacement are compelling reasons to explorenother avenues for immune matching [1].