Induced pluripotent stem cells (iPS cells) are specialised adult cells that have been reprogrammed to behave like embryonic stem cells. They were first made by Shinya Yamanaka in 2006, using mouse skin fibroblasts, and from human cells in 2007.How they are made
Specialised cells have most of the genes needed for pluripotency switched off. Scientists switch these back on by introducing genes that code for four transcription factors (Oct4, Sox2, Klf4 and c-Myc). The genes are usually inserted using a viral vector. The transcription factors activate the network of genes that keeps a cell undifferentiated, and a small proportion of cells become pluripotent.
Uses
• Cells from a patient can be turned into iPS cells and then into the affected cell type, giving a model of that person's disease for research and drug testing.
• In the future, tissue made from a patient's own iPS cells could be transplanted without rejection. Early trials have used retinal cells made from iPS cells.Problems
• One of the genes, c-Myc, is an oncogene, and viral vectors insert DNA into the host chromosomes, so there is a risk of cancer.
• The process has low efficiency: only a small fraction of treated cells are fully reprogrammed.
• iPS cells are not identical to embryonic stem cells and may not differentiate as reliably.
Specialised cells have most of the genes needed for pluripotency switched off. Scientists switch these back on by introducing genes that code for four transcription factors (Oct4, Sox2, Klf4 and c-Myc). The genes are usually inserted using a viral vector. The transcription factors activate the network of genes that keeps a cell undifferentiated, and a small proportion of cells become pluripotent.
Uses• Cells from a patient can be turned into iPS cells and then into the affected cell type, giving a model of that person's disease for research and drug testing.
• In the future, tissue made from a patient's own iPS cells could be transplanted without rejection. Early trials have used retinal cells made from iPS cells.Problems
• One of the genes, c-Myc, is an oncogene, and viral vectors insert DNA into the host chromosomes, so there is a risk of cancer.
• The process has low efficiency: only a small fraction of treated cells are fully reprogrammed.
• iPS cells are not identical to embryonic stem cells and may not differentiate as reliably.