One of Assay Depot’s most popular blog posts of last year was an infographic depicting American attitudes towards stem cell research.  Part of that picture was a graph showing government spending on stem cell research.  In 2009, the NIH funded non-embryonic stem cell research to the tune of more than $350 million.  In 2010, that number dropped to less than $50 million.  Funding for embryonic stem cell research dropped by more than half, from $125 million in 2009 to less than $50 million in 2012.

Why the sudden drop in funding for stem cells?

It was probably due to a lawsuit filed by two scientists who were attempting to block federally-funded embryonic stem cell research on ethical grounds.  The lawsuit purported that such funding violated the 1998 Dickey-Wicker law, which prohibits taxpayer-based funding for any research that involves harm to human embryos.  This Monday, the Supreme Court refused to hear the appeal.  Stem cell research gets another green light.

In a field that has been victim to political winds, suffering constantly changing rules, there is hope that induced pluripotent stem (iPS) cells can avoid some of the ethical controversy that has plagued embryonic stem cell research.  iPS cells are pluripotent stem cells that are derived from terminally differentiated cells, such as blood, fat, bone marrow, and skin.  This reverse engineering of stem cells is accomplished by introducing four transcription factors, turned on in stem cells, into terminally differentiated cells.  This discovery has so revolutionized the field of stem cell research that its initial pioneer, Shinya Yamanaka, was awarded the 2012 Nobel Prize in Physiology or Medicine.  He shared the prize with John Gurdon, who developed the nuclear transfer techniques used in cloning that lay the groundwork for cell reprogramming.

stem cell

The discovery of induced pluripotent stem cells (iPS) has changed the field of regenerative medicine. iPS cells raise fewer ethical issues than embryonic stem cells. They also allow researchers to study hard-to-reach cells, such as heart cells or neurons, from specific patient populations. Image source: Junying Yu, University of Wisconsin-Madison

Because iPS cells are derived from consenting donors, some of the ethical issues associated with embryonic stem cells are avoided in iPS-based stem cell research.  In addition to changing people’s attitudes towards stem cell research, iPS cells have also changed the scope of stem cell research. Initially, the goal was to use stem cells as a therapeutic to treat disease.  While that is still one objective, another avenue of research is to make stem cells from patient populations and differentiate them into hard-to-study cell types.  These differentiated iPS cells can be used to identify molecular pathways involved in disease, to screen drugs, and to test drugs for cellular toxicity.  These concepts of “disease in a dish,” and creating virtual early-phase clinical trials in a tube, will be explored in our next blog post in this series.