The undoing of differentiation by four defined factors: A big step forward towards generating patient specific pluripotent stem cells

摘要

Embryonic stem cells (ESC), derived from the inner cell mass of the blastocyst, are pluripotent cells capable of differentiating to all somatic and germ cells of the body. ESC were first isolated from mouse blasto-cysts in 1981 . It was not until their isolation from human blastocysts in 1998 that ESC were viewed as an inexhaustible source of cells that might be used for regenerative medicine, even though the allogeneic nature of ESC-derived cells or tissues would necessitate life long immunosuppressive therapy. The need to destroy human blastocysts has also raised ethical concerns. Although near-autologous ESC, created using somatic cell nuclear transfer (SCNT) , would circumvent the allogeneic nature of ESC, the need for unfertilized human oocytes and the possibility to exploit this technology for reproductive cloning raises further ethical concerns.