Embryonic Stem cell
lines are most conventionally isolated from the inner cell mass of very early embryos (blastocysts) and, in a few instances, from cleavage stage embryos. So far, there were no reports in the literature of human stem cell lines derived using an approach that can work without
Embryo destruction. A long awaited goal of acquisition of
Embryonic stem
cells for therapeutic use and other important applications, without the destruction of embryo was recently claimed to be achieved (Klimanskaya et al.,
Nature doi:10.1038/nature05142; 2006;
Nature, 24th Aug., 2006 issue) by the
research team of Advanced Cell Technology in Worcester, Mass.,
USA. It was discovered that a few (1-2) embryonic cells could be taken from a live embryo (while in uterus) for the establishment of stem cells lines, leaving the embryo to survive and develop normally. This was considered to be a medical milestone and a major turning point, paving way for beneficial gains in treating or curing diseases such as diabetes, spinal cord injuries and Alzheimer’s disease. The technique not only claimed to circumvent destruction of embryo, but also ensured that the biopsied cell does not develop into an embryo and is only useful toward generating the stem cell lines. Dr. Robert Lanza, the leader of this research team, was quite optimistic about this breakthrough study, but he also expressed his concern in that, whether this strategy would grow and widen or not, will ultimately depend only on politicians rather than scientists. The report was also followed by a backlash, as it became clear that all of the embryos used in this study, were destroyed and there were no live embryos remaining after the execution of the experimental protocols. Lanza as well as the journal Nature have been accused of hyping the results reported in the paper.This
study has reported an improvised method described by the team earlier. In that study, the group succeeded in cultivating mouse embryonic stem cell lines by removing just one cell from the mouse embryo (Chung et al., 2006). The procedure is described to be similar to that used for pre-implantation genetic diagnosis (PGD), normally utilized to check for genetic disorders during in vitro fertilization (IVF). In this case the embryos survive, as the technique doesn’t interfere with developmental potential of the embryo. The new research, however, took an extra painstaking effort, which deployed a very different technique. It involved the use of 16 human embryos left over from IVF. The group used single-cell biopsy technique to pluck one stem cell when the embryo was at the 8-10 cell stage. This is the same stage used for pre-implantation genetic diagnosis of the embryos. Excising a cell at this point and growing it further doesn’t interfere with embryonic development. However, as the cells apparently do not like being co-cultured alone, they were put into a dish with other cells. This technique helped them to keep them alive for a long time in culture conditions. Using this method, Lanza’s team managed to get two stable lines that behaved like the conventional stem cell lines. The lines have been proven to be genetically normal and have been tested to generate all the cell types of the body to further prove their authenticity. The real importance of this study that involved ten different experiments has the potential that we could indeed have the stem cell lines that are pluripotent from the embryos, which aren’t destroyed. With all the right kind of resources, we could thus recreate as many lines as the stem cell research community needs without unnecessarily harming or killing the embryos. However, this so called “ethical paper” which initially attracted the media excitement, has been under attack for several reasons now. Many of the known experts in the field have also been disappointed over this confusion so soon after the Woo-Suk–Schatten scandal in which they had claimed to create embryonic stem cell lines from cloned embryos. Although the paper is not scientifically incorrect, it only shows “a proof of principle” that a human embryonic cell line can be created from a single cell or blastomere, from a very early embryo which can survive but the reality is that none of the embryos survived in the experiments that were carried out. The Nature paper’s details and the supplementary information later made it clear that all the embryos were broken up, stating that 91 cells were used from 16 embryos. Only two stem-cell lines were created, so the efficacy was barely 2% which is much lower. Within minutes of the paper going live, Nature’s press office corrected its press release to say that Lanza’s experiments had destroyed some of the embryos, but a second note two days later confirmed that all the embryos were destroyed. Therefore, it would rather be more ethical to work on the embryos that are meant to be destroyed anyway. If research is done for the purpose of only getting around the law and for acquiring more funding, it makes things worse and also makes science look dishonest. As of now, science is in grave danger of devolving into special interests and politics. This intense politicization of science greatly threatens to erode public’s trust in the entire science sector. Thus, it is high time that researchers organize themselves and become more radical to see to it that they do not give in to such spurious breakthrough announcements at the first go.
More abstracts about the Stem Cells Derived without Destruction of Embryos: A Breakthrough Study or a Study Breaking the Back