In August 2006, Advanced Cell Technology reported that company scientists had successfully generated human embryonic stem cells (hESCs) using an approach that does not destroy the developmental potential of embryos. The technique was reported in an article appearing in the journal Nature. The article described a method for deriving stem cells from human blastomeres with a single-cell biopsy technique called Preimplantation Genetic Diagnosis (PGD). This technique is used in in vitro fertilization (IVF) clinics to assess the genetic health of preimplantation embryos. The cell lines produced using this technique appeared to be identical to hESC lines derived from later stage embryos using techniques that destroy the embryo’s developmental potential. ACT had previously reported the successful use of a similar technique in mice in Nature in October 2005. To create hESC lines, the researchers used single cells obtained from unused embryos produced by IVF for clinical purposes. Nineteen stem-cell outgrowths and two stable hES cell lines were obtained. These cell lines were genetically normal and retained their potential to form all of the cells in the human body, including nerve, liver, blood, vascular, and retinal cells that could potentially be used to treat a range of human diseases.
The blastomere technology has been reproduced and peer-reviewed on several occassions. In June 2007, ACT announced at the fifth annual meeting of the International Society for Stem Cell Research (ISSCR) in Cairns, Australia, that it had reproduced its work by successfully producing a human embryonic stem cell line without destroying an embryo at its lab in Worcester, Massachusetts. In January 2008, ACT together with colleagues announced the development of five hESC lines without the destruction of embryos. The new method was published in the journal Cell Stem Cells, published by Cell Press. The peer-reviewed technique was initially carried out by ACT scientists under the direction of Robert Lanza, M.D., and then independently replicated by scientists on the West Coast. Single cells were removed from the embryos using a technique similar to PGD. The biopsied embryos continued to develop normally and were then frozen. The cells that were removed were cultured utilizing a proprietary methodology that recreates the optimal developmental environment, which substantially improved the efficiency of deriving stem cells to rates comparable to using the traditional approach of deriving stem cells from the inner cell mass of a whole blastocyst stage embryo. The stem cells were genetically normal and differentiated into cell types of all three germ layers of the body, including blood cells, neurons, heart cells, cartilage, and other cell types of potentially therapeutic significance. The paper also addressed several other important issues. First, the stem cells were derived without culturing multiple cells from each embryo together and at efficiency levels similar to that reported for conventional stem cell derivation techniques using blastocysts. Second, it addressed ethical objections that the derivation system required co-culture with hESCs from other embryos that were destroyed. The study demonstrated that hESC co-culture is not an essential part of the derivation procedure. The stem cell lines generated in the study appeared to have the same characteristics as other hESC lines, including expression of the same markers of pluripotency, self-renewing capacity, genetic stability, and ability to differentiate into derivatives of all three germ layers of the body.
Other existing technologies derive hESCs from the inner cell mass of later-stage embryos known as blastocysts, destroying their potential for further development. The destruction of the embryo’s ability to develop further has caused the most significant amount of controversy over human embryonic stem cell research. Moreover, the destruction of the embryo’s developmental potential has also caused the federal government (via the executive branch) to ban the use of federal funds to research embryonic stem cell science in humans, despite Congress’s voting in favor of lifting the ban. ACT’s approach generates human embryonic stem cells from a single cell obtained from an 8-cell-stage embryo and does not impact the developmental potential of the embryo – directly addressing the executive branch’s concerns.
In September 2007, the National Institutes of Health (NIH) announced that it would begin implementing President George W. Bush’s Executive Order to explore methods to expand the number of approved pluripotent stem cell lines “without creating a human embryo for research purposes or destroying, discarding, or subjecting to harm a human embryo or fetus.” The announcement followed an Executive Order issued by President Bush on June 20, 2007, requiring that “The Secretary of Health and Human Services … conduct and support research on the isolation, derivation, production, and testing of stem cells that are capable of producing all or almost all of the cell types of the developing body and may result in improved understanding of or treatments for diseases and other adverse health conditions, but are derived without creating a human embryo for research purposes or destroying, discarding, or subjecting to harm a human embryo or fetus.” ACT’s blastomere program was cited by the NIH as an alternative method in its implementation plan. The NIH plan calls for “aggressively pursuing an assessment of the potential of alternative sources of pluripotent stem cell lines, including altered nuclear transfer; single cell embryo biopsy, and reprogramming, or dedifferentiation of somatic cells, such as skin cells.” Should the company’s blastomere technique satisfy NIH qualifications, ACT could qualify for federal funding from the NIH.