Therapeutic cloning with adult stem cells

Publié le : 22 April 2014

 Last week, in the Stem Cell journal, a team of American scientists (California) published the results of their research enabling them to clone adult human stem cells to create embryo stem cells. These results have generated enthusiastic comments and have rekindled the debate on therapeutic cloning.     

For the first time, adult stem cells have been cloned to obtain embryo stem cells. The scientists employed the same technique as that used 11 months earlier by Dr. Shoukhrat Mitalipov and his team (Oregon) (Gènéthique press review on May 13th, 2013). Therapeutic cloning known as somatic cell nucleus transfer (SCNT), involves producing embryo stem cells that are genetically identical to the donor in an attempt to treat a disease. In 2013, the Oregon team succeeded in creating embryo stem cells from skin cells using DNA taken from an 18-month old infant. This time the study involved the extraction of DNA from two men aged 35 and 37, explained Professor  Robert Lanza, Scientific Manager of Advanced Cell Technology (ACT). The nuclei of the skin cells taken from the 2 men were transferred to 77 oocytes of four female donors following removal of the oocyte nuclei. The 77 oocytes generated 2 lines of embryo stem cells.      

Scientists claim that the results obtained are rather modest. Firstly because “four female donors (each paid several thousand dollars) were needed to obtain 77 oocytes” and secondly because only three embryos reached the blastocyst stage. Consequently “2 lines out of 77 attempts are hardly encouraging, even from a purely technical perspective”

Therapeutic cloning with adult stem cells nevertheless creates and destroys embryos. The urgency adopted by the French Press Agency and taken up by the French-speaking press lacked precision. It suggests that the ethical questions raised by the destruction of fertilised embryos are being swept under the carpet with this new technique. Therapeutic cloning using adult stem cells to obtain embryo stem cells involves creating an embryo by cloning. In this particular study, “77 embryos had to be created and destroyed to obtain 2 cell lines”. The controversy is far from over!

The United States prohibits the use of federal funds for therapeutic and reproductive cloning. This study was partly financed by the South Korean Government.

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