In 2007, scientists developed a breakthrough method to convert adult cells of the body into an embryonic stem cell-like state referred to as reprogramming or induced pluripotent stem (iPS) cells.  This offered the hope that future cell-based therapies can be genetically matched to the patient, without needing drugs to prevent rejection.

So, why do we need human embryonic stem cells, adult and iPS cells?

• Human embryonic stem cells can become any cell type in the body through differentiation (a property known as totipotency) but it is essential that we know more about the molecular properties to determine the quality and potential of the human iPS cells.
• Human iPS cells produced in different labs around the world are not identical. Human embryonic stem cells, considered the “gold standard,” have been studied for over 12 years.  Recent studies have identified important differences between the two.

Scientists at University of Wisconsin–Madison compared the ability of both types of pluripotent cells to form human neurons in a laboratory setting and found a gene flaw causes iPS cells to grow more slowly and age more quickly then embryonic stem cells.¹

Singapore scientists discovered a particular gene that makes it easier to turn a type of human cell into a pluripotent stem cell, but the gene doesn’t work with mouse embryonic stem cells.  This highlights the difference between the species and the need to use human cells in research. ²

Researchers at Hebrew University in Israel are warning that using a patient’s own stem cells to replace diseased or damaged tissues could raise cancer risks. ³

• To work with iPS cells, embryonic stem cells are needed to determine the best laboratory practices.

Progress in biomedical research would have been far slower if the isolation and study of human embryonic stem cells had not provided the critical groundwork needed to produce human iPS cells.  Embryonic stem cells serve as THE standard for totipotency (total capacity to generate new cells) and all induced pluripotent stem cell and adult stem cell potential for differentiation must be measured against these cells.  At this stage of the research, we still need both.