Reprogramming of human somatic cells to pluripotency with defined factors

Pluripotency pertains to the cells of early embryos that can generate all of the tissues in the organism. Embryonic stem cells are embryo-derived cell lines that retain pluripotency and represent invaluable tools for research into the mechanisms of tissue formation. Recently, murine fibroblasts have been reprogrammed directly to pluripotency by ectopic expression of four transcription factors ( Oct4 , Sox2 , Klf4 and Myc ) to yield induced pluripotent stem (iPS) cells. Using these same factors, we have derived iPS cells from fetal, neonatal and adult human primary cells, including dermal fibroblasts isolated from a skin biopsy of a healthy research subject. Human iPS cells resemble embryonic stem cells in morphology and gene expression and in the capacity to form teratomas in immune-deficient mice. These data demonstrate that defined factors can reprogramme human cells to pluripotency, and establish a method whereby patient-specific cells might be established in culture. Stem cells get personal Another important step in the rapidly developing world of human stem cells is reported in this issue. Human cells taken from adult donors have been reprogrammed to produce iPS (induced pluripotent stem) cells, resembling embryonic stem cells in their main characteristics. It may soon be possible to use such procedures routinely to isolate patient-specific cells in culture. This paper reports the ability to isolate human donor biopsies and use transcription factors to derive induced Pluripotent Stem (iPS) cells from fetal, neonatal, and adult human primary cells, including dermal fibroblasts isolated from a skin biopsy of a healthy adult volunteer. The human iPS cells resembled embryonic stem cells in their morphology and gene expression. These data establish a method to isolate iPS cells from patients, suggesting that it may be possible to use this procedure to isolate patient-specific cells in culture.