Pro-life warnings over a new form of stem cell research appear to have been proved correct, with researchers now having cloned live mice using a method of creating multi-use stem cells that had been hailed by some - including some in the pro-life community - as an ethical breakthrough. At the same time other pro-life figures, such as bioethics expert Dianne Irving and physician Dr. John Shea, have warned that the technique could involve killing newly formed embryos.
Two teams of Chinese researchers have cloned a set of live mice from induced pluripotent stem cells, or iPS cells. The iPS technique, discovered in 2007 by Dr. Shinya Yamanaka of Kyoto University, is a method of "reprogramming" adult cells to become "embryonic-like" iPS cells. However, the Chinese groups said they used the technique, not simply to create "embryo-like" cells, but to create whole cloned mice that have only one biological "parent" or progenitor. The work was reported online this week in the journals Nature and Cell Stem Cell.
Animal cloners Qi Zhou of the Institute of Zoology in Beijing and Fanyi Zeng of Shanghai Jiao Tong University introduced four genes into fibroblast cells of mice, hoping to "reprogram" the cells so that they could differentiate into any type of cell in the body. When transplanted into a 'tetraploid' embryo - one that would produce a placenta, but has no embryonic inner cell mass - the reprogrammed cells became whole mouse embryos that were later transplanted into surrogate mothers.
Ultimately the Chinese teams reported 22 live births from 624 injected embryos, a success rate of 3.5 percent. The cloned mice, however, have a high death rate, with some dying after just two days, and others displaying physical abnormalities. 12 of the survivors were mated and produced offspring that showed no sign of abnormalities.
In March this year, two independent teams in Britain and Canada took the Yamanaka research to what they said was the next step, and devised what they called a safer technique for reprogramming adult cells so that they become "pluripotent" stem cells. At that time, bioethics expert Dianne Irving told LifeSiteNews.com that there must be caution among pro-life advocates in endorsing the work.
She warned, "No test is reported to determine if totipotent cells (which could be newly formed human embryos) are inadvertently formed while producing iPS cells."
With the new Chinese discovery, pro-life advocates are again sounding the alarm. Dr. John Shea, medical consultant for Canada's Campaign Life Coalition, told LifeSiteNews.com that iPS cells are simply cloned embryonic stem cells that have the inherent potential to "revert" to an embryo.
It has always been known, he said, that the cells have the potential to "revert into an embryo that is identical to the one from which it was separated." "The planned separation of an embryonic stem cell is a technique used in fertility clinics. Therefore iPS is a form of cloning, and the use these cells for research involves or may involve the killing of a human beings," he said.
Contact: Hilary White
Source: LifeSiteNews.com
Publish Date: July 27, 2009
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