Stem cells: you can't tell a cell by its cover.
Embryonic stem (ES) cells are capable of unlimited self-renewal and have the ability to give rise to all tissue types in the body. The use of human ES cells for tissue and cell therapeutics has been suggested, but is limited by ethical concerns as these cells are derived from the inner cell mass of human embryos. In addition, the need for HLA matching of ES cell-derived tissues for allogeneic transplantation would require a bank of several thousand ES cell lines to make tissue therapeutics practical. Recently, adult stem cells-of which those in bone marrow are the best studied-have been shown to be capable of multilineage differentiation into cells of various non-blood tissues. Umbilical cord blood (UCB) haematopoietic stem cells have been shown to be equivalent to bone marrow stem cells for reconstitution of the haematopoietic system. Preliminary studies have also demonstrated that UCB haematopoietic stem cells are multipotent and capable of differentiating into non-blood cell types. This observation raises the exciting possibility of replacing human ES cells for tissue and cell therapeutics with UCB blood haematopoietic stem cells that are normally discarded with the placenta after delivery.
Rogers
Ian
I
Division of Reproductive Sciences, Fran and Lawrence Bloomberg Department of Obstetrics and Gynecology, Samuel Lunenfeld Research Institute, Mount Sinai Hospital and The University of Toronto, Toronto, Ontario, Canada.
Casper
Robert F
RF
D000328:Adult; D001854:Bone Marrow Cells / Q000166:cytology*; D002454:Cell Differentiation / Q000502:physiology; D005312:Fetal Blood / Q000166:cytology*; D006801:Humans; D007231:Infant, Newborn; D033581:Stem Cell Transplantation; D013234:Stem Cells / Q000166:cytology*