May 26, 2009
In case you haven’t kept track (very hard to do with this area), there are an increasing number of publications detailing the advantages of iPS cells (induced pluripotent stem cells) over ES cells (embryonic stem cells).
iPS cells provide a relatively easy and inexpensive method for creation of ES-type cells directly from virtually any tissue source or individual. They were first developed in 2006 in mice by the Japanese scientist Shinya Yamanaka, and in November 2007 both Yamanakas lab and the lab of James Thomson in the U.S. showed that this same technique could work for human cells as well.
The original Yamanaka reprogramming technique involved adding four genes directly to a human cell such as a skin fibroblast cell, with the genes added using a viral vector. The technique has advanced rapidly in less than three years, and reprogramming of iPS cells has now been accomplished completely without the use of added DNA sequences, by using added protein reprogramming factors.
The behavior of iPS cells appears virtually indistinguishable from ES cells. Thomsons group in their seminal paper producing human iPS cells noted:
The human iPS cells described here meet the defining criteria we originally proposed for human ES cells, with the significant exception that the iPS cells are not derived from embryos.
Thomson has also pointed out the ethical advantage of iPS cells:
These cells possess the therapeutically desired characteristics of ES cells, namely indefinite self-renewal and pluripotency, without the requirement of human embryo destruction.
iPS cells fulfill the desire to create ES cells, with the added advantage of easy and cheap creation directly from a patient, and the potential for transplant match, but do all of this without the use of embryos, eggs, or cloning. Within one year of the first report of human iPS cells, at least 315 human iPS cell lines had been generated, and over 500 total human iPS cell lines have now been reported. In addition, iPS cell lines from patients suffering from various diseases have been created, covering 13 different diseases.
iPS cells provide all of the desired characteristics of pluripotent ES cells, and also distinct advantages in terms of their ethical creation as well as ease and cost of creation, and production directly from patients.
To see a semi-complete listing of recent iPS cell publications
To see a summary of human iPS cell lines created