Embryonic Stem Cell Technique That Doesn’t “Harm” Embryos is Problematic

Bioethics   |   Rebecca Taylor   |   Jan 16, 2013   |   5:57PM   |   Washington, DC

It happens almost every time. When I write a piece about embryonic stem cell research, I get an e-mail or comment, sometimes polite, most of the time not, that goes something like this, “If you were not such a scientifically-ignorant pro-lifer, you would know that Advanced Cell Technology (ACT) can make embryonic stem cells without harming the embryo at all. I am much smarter than you and now that you are enlightened with this revelation, you can support embryonic stem cell research like I do.”

I am very aware of ACT’s patented “single cell blastomere technology” which removes a single cell from an 8-10 celled embryo and then grows embryonic stem cells from the single-cell biopsy. (A “blastomere” is a cell from an early embryo.) From the ACT website:

ACT’s proprietary, patented single-blastomere technology enables the derivation of hESCs from human blastomeres using a single-cell biopsy technique similar to Pre-implantation Genetic Diagnosis (PGD). The biopsy procedure does not destroy or harm the embryo, nor does it interfere with the embryo’s developmental potential. PGD is often used in in vitro fertilization (IVF) clinics to assess the genetic health of pre-implantation embryos. The cell lines produced using this technique appear to be identical to the hESC lines derived from later-stage embryos, derived using techniques that destroy the embryo’s developmental potential.

I and many of my fellow pro-lifers know about ACT’s “advance” that supposedly removes all objections to embryonic stem cell research. We know about it; it just does not allay our issues with research on human embryos.

Being pro-life means more than just being concerned with embryo-destruction. We pro-lifers understand that these embryos are complete human organisms, albeit early in development, and so deserve respect and protection. Is taking a single cell from such a young human being for research respecting and protecting them? Would anyone promoting this procedure be willing to let ACT remove 1/8th of their offspring in the name of stem cell research?

ACT says this procedure does not harm the embryo or interfere with the “embryo’s developmental potential.” I am sure they are sure that the embryo, while in the embryonic stage, is not visibly harmed. ACT says this procedure is like pre-implantation genetic diagnosis (PGD) used in IVF. Let us see what fertility experts say about the inherent risks of PGD. From The Fertility Authority:

The risks of PGD include damage to the embryo during the biopsy procedure, according to Serena H. Chen, M.D., a New Jersey reproductive endocrinologist with IRMS Reproductive Medicine at Saint Barnabas. “The good news is that embryos damaged by PGD appear to experience an “all or none” effect — they stop growing, rather than sustain long-term damage,” she says. Embryos that continue to grow after the biopsy do not become abnormal as a result of the biopsy and are not at greater risk for miscarriage or birth defects.

However, “There is a general misconception that the whole embryo biopsy process is just another ‘option’ in the IVF/embryo transfer menu, like ICSI, assisted hatching, blastocyst transfer, cryopreservation and so forth. The most important thing to remember about PGD/PGS is that it is an invasive technology,” says Michael Tucker, Ph.D., Scientific Director and Chief Embryologist at Georgia Reproductive Specialists in Atlanta. “At least one cell or more must be removed from each embryo to enable the assessment to take place, and as such it is not a procedure that should be undertaken lightly. For single gene defects and chromosomal structural anomalies that have a high probability of appearing in the next generation, then such an invasive procedure as embryo biopsy is justifiable, even though the embryo viability might be partially compromised.”

So it seems embryos are damaged by the biopsy process. It is an “invasive procedure that should not be undertaken lightly.”

And for the embryos that survive the biopsy, what are the long term risks? No one really knows. But a study in mice suggests that PGD does have some long term effects. From the American Medical Network:

Ran Huo, Qi Zhou and colleagues used a mouse model to examine how a blastomere biopsy, as the key manipulation during the PGD procedure, could affect fetal, neonatal and adult development.

They found that there were no differences in embryo development prior to uterine implantation in the biopsied and control groups, which is consistent with results found in humans. However, following implantation, successful births from biopsied embryos were significantly lower than in controls.

Following birth, the authors tracked many physical and behavioral properties; the two groups of mice were similar in many respects, though mice in the biopsied group on average had higher body weight and poorer memory in maze tests. To get a more detailed picture of these memory defects, the authors performed a proteomic analysis of adult mouse brains; 36 proteins displayed significant differences between biopsied and control groups, 17 of which are closely associated with neurodegenerative disorders like Alzheimers and Down Syndrome.

The authors suggest that the developing nervous system may be sensitive to blastomere biopsy, and that more studies should be performed to address any possible long-term adverse effects of PGD to ensure its safety.

These researchers are calling for more research into the safety of PGD because in mice, a biopsy of the embryo caused lower birth rates and markers for neurological disorders.

So I am not convinced that ACT’s technique does no harm, ever. How about we stop experimenting on very young human beings without their consent? How about we stop taking their parts as if they were no more than harvestable biological material?



In addition, ACT has a patent on this technique which means other researchers are still destroying embryos to harvest embryonic stem cells.

“Single cell blastomere technology” may sound good, but it really does nothing to address the concerns of pro-lifers about the creation, manipulation and harm done to nascent human life in the name of science.