Highlights from the Dateline NBC broadcast
Dateline NBC & Dr. Kiessling
Dateline reporter Josh Mankiewicz interviewed Foundation director, Dr. Ann Kiessling, about why human embryonic stem cell research is so controversial. Dr. Kiessling’s responses were based on the following information:
The rancorous US debate about embryonic stem cells bespeaks a healthy society, with genuine, deeply-held concern about each and every being it engenders, the tiniest and the sickest. Everyone, on both sides of the debate, wants to do what’s right.
But what is “right?”
Should frozen embryos “left-over” in fertility clinics be “sacrificed” to create the stem cells to treat heart failure, autoimmune diseases, diabetes, osteoporosis, cancer, Alzheimer’s disease, Parkinson’s disease, spinal cord injuries, and birth defects? (Science pdf)
The answer is not necessarily.
In fact, “left-over” frozen embryos are not the most useful sources of pluripotent stem cells for therapy. Their major problem is that human embryonic stem cells will have the same tissue compatibility problems as other transplanted organs.
What stem cells should be used for therapy? There are two types that have not been part of the debate. Pluripotent human stem cells for therapy developed from activated eggs and nuclear transplantation.
Type 1: “Activated eggs” (Parthenotes)
Human eggs are huge cells with the capacity to resume cell division without being fertilized by sperm. This occurs naturally in women, giving rise to dermoid cysts and teratomas. Women are born with about one million eggs. By the time they are 50 years old, the eggs have all died. Thus, about 20,000 eggs naturally die each year, in the ovary; she ovulates about a dozen.
The challenge is to harness the capacity of the egg to start over, to give rise to new, pluripotent stem cells, once it is activated. This is a natural, obvious source of stem cells for ovulating women with serious diseases, such as diabetes and spinal cord injury, because they will not have the tissue rejection problems.
Activation of human eggs for stem cells was first reported in 2001, (pdf article) but a continuous line of stem cells was not achieved. The research is ongoing in Bedford Stem Cell Research Laboratories with private funding; the research cannot be funded by federal dollars because of the moratorium on funding research on all “activated” human eggs.
Parthenote stem cells were developed from a monkey egg in 2000 (pdf article), and have been shown to give rise to the same types of cells as stem cells derived from human embryos “left over” in fertility clinics. They are currently being used in several lines of research, including treating Parkinson’s disease in monkeys.
Type 2: Nuclear Transplant stem cells (Ovasomes: somatic (“body”) cells from (“ova”) eggs)
Eggs have the remarkable capacity to “remodel” genetic information introduced into them, just like it “remodels” sperm at fertilization. This powerful capacity is not fully understood. It can erase the memory in the genes of a skin cell that made it a skin cell, and convert it back to a pluripotent stem cell. It does this without its own chromosomes. Then, when activated, the egg uses the new genetic information to divide into a line of stem cells genetically identical to the skin cell donor. Because this same basic technology led to cloning Dolly the sheep in 1997, there is fear it could lead to cloning a human. Such fears could be set aside by proper legislation to outlaw using nuclear transplantation technology to clone a human.
Attempts to develop human nuclear transplant stem cells (ovasomes) were first reported in 2001, but the activated eggs stopped dividing, and stem cells did not develop (pdf article). In March, 2004, the first ovasomes (nuclear transplant stem cells) were developed in a laboratory in Korea (pdf article). The cells were shown to develop into all the same cell types as human embryonic stem cells and the monkey parthenote stem cells.
Current status of research:
Congress placed a moratorium on funding research on all forms of activated human eggs, including parthenotes and nuclear transplanted eggs, in 1996. President Bush extended the moratorium to include funding the derivation of stem cells from “left-over” human embryos in 2001.
Therefore, the research can go on only in privately funded laboratories. The Bedford Stem Cell Research Foundation is currently conducting research with unfertilized human eggs. The eggs are donated by woman recruited and cared for by the rigorous guidelines developed specifically for stem cell research by an ethics advisory board chaired by Professor Ron Green, Dartmouth College. As a Massachusetts public charity, the BSCRF conducts controversial stem cell research under public scrutiny and ethical guidelines, while taking advantage of low administrative costs.
The House of Representatives has twice passed a bill that would outlaw all research on activated human eggs. Fortunately, the Senate has not passed the bill, so for the present, the research remains legal, but not fundable by federal dollars.
Hopes for the near future:
- That the House of Representative’s bill outlawing all research on activated human eggs not be allowed to become the law of the land.
- That sufficient private funding be available to continue the research to develop stem cells from unfertilized human eggs; funding from private sources is potentially equal to funding available through the National Institutes of Health.
With a total budget of approximately 30 billion dollars spread over nearly 20 Institutes and programs, the NIH distributes about 18 billion dollars a year to US scientists. Without cutting funds to other meritorious programs, the NIH will not be able to dedicate substantial funds to pluripotent stem cell research for several years, even if the research is approved by President Bush. Thus, the funds must come from the private sector.
- That the moratorium on federal funding be re-written to not include research on unfertilized human eggs, thus making available federal research funds in addition to the private funds.