Some achievements are heroic, some advance technology in a way that changes lives for the better, and others exist solely to bring a measure of fame to the doer. Despite a flurry of media coverage, a recent report of cloning human embryos seems likely to take its place joining a plethora of Guinness records such as the largest ball of yarn and the highest number of consecutive somersaults. But while this accomplishment involves multiple ethical problems and offers no immediate promise to those awaiting new treatments for diseases, it does serve to highlight the technical expertise of the researchers and looks good on a grant application.
In an article published in the high-profile journal Cell, Dr. Shoukhrat Mitalipov’s research group reports the first successful generation of human embryonic stem cells by somatic cell nuclear transfer (SCNT). Briefly, the nucleus of an egg cell is replaced with the nucleus of a somatic (non-gamete) cell, so that the egg ends up with the full complement of human genetic material without the need of a sperm cell.
The egg becomes a clone of the source of the somatic nucleus inasmuch as they share all the same genetic information. The researchers, located in Oregon, were then able to use these “reprogrammed” cells to produce embryonic stem cells (ESCs) similar to those obtained directly from human embryos.
The creation of human embryos in this way is prohibited by Catholic teaching, regardless of whether the intention of the researchers is to generate a baby (reproductive cloning) or to generate cells or tissues to treat diseases (therapeutic cloning).
Cardinal Sean P. O’Malley of Boston issued a statement saying, “Creating new human lives in the laboratory solely to destroy them is an abuse denounced even by many who do not share the Catholic Church’s convictions on human life,” noting that over 120 embryos were destroyed in the course of this research.
Further compounding the ethical difficulties, the source of donor nuclei is skin cells from aborted human fetuses. The company providing these cells has issued a disclaimer saying that they “believe that…the provision of normal human cells for research use only does not […encourage] or pressure women to undergo abortion.”
From a technical perspective, this report is notable because it is the first report of successful reprogramming of human somatic cells into ESCs following SCNT. It is not the first time this technique made headlines, however.
In 2004, a Korean researcher claimed to have achieved a similar result before it was exposed as a fabrication, along with further allegations of embezzlement and other ethical violations. Before the ensuing collapse of his career, he was awarded millions of dollars for further research.
Many things have changed since 2004. In 2007, a Japanese scientist first generated induced pluripotent stem cells (iPSCs) – a functionally comparable and ethically uncontroversial source of stem cells that won him a Nobel Prize in 2012. Meanwhile, scientists have discovered plentiful sources for adult (or somatic) stem cells, which have great therapeutic potential because of the fact that in many cases, the stem cells can be isolated from the patient and avoid the risk of graft rejection when tissues derived from those cells are reintroduced during treatment.
Meanwhile, the much-hyped promise of human embroyonic stem cell (hESC) treatments remains unfulfilled. In a clear public sign of recognition that they had backed a loser, hESC champion Geron Corporation stopped work on stem cell research in 2012 due to lack of funds.
While experts in the stem cell field are quick to credit the technical expertise of the Oregon group for having succeeded where many others have failed, they are far more cautious when discussing the future implications of this work. Dr. Rudolf Jaenisch of MIT’s Whitehead Institute said that this result has “no clinical relevance.” Further Jaenisch adds that even if these cells are more versatile than iPSCs, “the consequence would be to make IPS cells better,” since the requirement for human egg cells is a difficult hurdle to overcome.
Other scientists expressed their adamant opposition to any effort to use this approach in reproductive cloning – that is, to implant the resulting embryos in a woman’s uterus. Experiments of this type in other species have produced viable offspring such as the famous sheep, Dolly, but such animals often exhibit health complications over time.
Ultimately, this report could be viewed as analogous to an engineer presenting the fastest new steam locomotive: a testament to his ingenuity, worthy of a few headlines, but a mainly symbolic advance in an area the scientific community has largely left behind. Cloning human embryos obviously creates enormous ethical concerns, and the technique used to generate them is full of controversial elements, from the need to convince women to donate their eggs for research to the use of aborted fetal tissue as a source of donor nuclei.
Additionally, regulatory obstacles remain. Lawmakers who previously backed away from pursuing anti-human cloning policies in the absence of scientific progress in that area would require little instigation to create increased regulations. Furthermore, due to existing laws, Mitalipov’s group had to use private funding for their hESC research. While private sources undoubtedly still exist – and this work establishes Mitalipov as a tough competitor to beat – it is unlikely that this breakthrough will precipitate a surge in new funding, given the current state of the field.
In short, this publication will likely advance Mitalipov’s own career, but he and his team may well be its sole beneficiaries. For those concerned with bioethics and the sanctity of human life, this is good news. It is also good news that this advance happened in 2013 rather than 2004, as it could have made a much greater impact in the absence of proven alternatives that are both ethical and efficacious.