Blue Penguin Report

By Red Sox Steve
Vagabond Guru

Last time, we examined the science behind DNA and stem cells. DNA is an instruction manual for the assembly of proteins that make up the human body, and stem cells are the earliest distinct units that make up specific parts of the human body. The potential to use DNA and stem cells for therapeutic purposes is the main driving force behind stem cell research in laboratories around the world. One of the key sources of funding for this research has been the US government, subject to policy distinctions made by each presidential administration starting around 1975.

In 1975, a US government entity called the Ethics Advisory Board (EAB) had been the only regulatory body with the power to award federal funding for In-Vitro Fertilization (IVF) research. At the time, IVF research was at the cutting edge of investigation into human embryos. Under Presidents Reagan and George H.W. Bush, the EAB was disbanded, and no embryotic research was funded. By 1994, the NIH, under President Clinton, had developed research guidelines for investigation of human embryos. In 1995 however, congress returned to Republican control, and a ban on both federal funding to create embryos for research and destructive embryotic research has been in place ever since. This was done via an amendment to the annual appropriations bill called the Dickey-Wicker amendment, and it has been attached to every appropriations bill since then.¹

In 1998, in Wisconsin, human stem cells were isolated and grown in a cell culture (under man-made and artificially controlled, external conditions) for the first time. The following year, the Department of Health and Human Services released a memo² to the NIH which stated that because stem cells extracted from human embryos were "pluripotent", they are not considered to be part of a living human embryo. As a result, the pluripotent stem cells which are extracted from human embryos do not fall under the federal ban on research funding, and any related research is eligible for federal funds.

To quickly revert to our earlier discussion, the term "pluripotent" (or, "pluripotency") refers to the fact that certain cells, in this case, stem cells, can differentiate into any type of cell needed by the human body; most immediately, they can form the three germ layers we discussed last time: the ectoderm, endoderm and mesoderm. Pluripotent stem cells, however, cannot form a fetus or human by themselves because they lack the ability to form a placenta, the organ within the womb that enables the uptake of nutrients by the fetus from the mother.

On August 9, 2001 President Bush made a speech³ in which he delineated his administration's policy on stem cell research: the government will permit funding on any embryonic stem cells that already exist as a result of IVF; however, no federal dollars will be set aside for research based on the extraction of new stem cells from embryos. In 2005 and 2006, a bipartisan bill passed both houses of congress to allow federal funding of research on stem cell lines from new embryos, but was vetoed both times by President Bush. The scientific rationale for Bush's opposition is that by removing stem cells from the embryo, scientists are destroying the possibility that those stem cells will go on to produce a living organism.

In March 2009, President Obama changed the policy again⁴, repealing the ban on funding of research with new stem cell lines. Similar to his predecessors, he wouldn't approve spending federal funds on work that would destroy the embryo solely for research purposes, or where ESCs were obtained from embryos created by processes like nuclear transfer (cloning) or parthenogenesis (reproduction).

Nuclear transfer requires the manual exchange of a nucleus (where the DNA is located) in an unfertilized egg for a nucleus containing DNA scientists wish to replicate. Parthenogenesis involves embryotic development without fertilization. In both cases, any extraction of stem cells would interrupt the growth and development of the embryo. Further, Obama's policy would ban federal funding where ESCs or induced pluripotent cells are introduced into "non-human primate blastocysts" or in animals where ESCs contribute to the germ line (recall our brief summary of the germ layers from last time).

Federal funding policy for stem cell research changes every time the White House changes parties, which stunts the growth of knowledge we can glean from research efforts. Currently, stem cell research has the federal funding it needs from the Obama administration, and new stem cell lines can be used for research. As we look forward in our discussion, we will explore the scientific challenges that researchers face, and take a look at potential therapies with ties to stem cell research.

Sources:

1) Journal of Law, Medicine & Ethics; Summer2010, Vol. 38 Issue 2, p191-203, 13p

2) 1999 memo: http://news.sciencemag.org/scienceinsider/Implementing%20New%20Federal%20hESC%20Research%20Policy.pdf

3) August 9, 2001 speech by G.W. Bush: http://www.c-spanvideo.org/program/CellResea/start/35/stop/679

4) March 9, 2009 speech by B. Obama: http://www.c-spanvideo.org/program/SSci/start/0/stop/1005