British regulators have given a cautious green light to research that would use animal eggs to produce patient-specific embryonic stem (ES) cells. The technique has already been tried--with little success--in several labs throughout the world, including in the United States, China, and South Korea. But when two groups in the United Kingdom applied to that country's Human Fertilisation and Embryology Authority (HFEA), which oversees embryo research, officials decided they needed a thorough review of the overall approach.
Some scientists hope that ES cells with the genetic signature of patients could help them understand diseases such as amyotrophic lateral sclerosis (ALS) and Alzheimer's disease. One way to create such cells is through somatic cell nuclear transfer (SCNT), in which the nucleus of a patient's cell is inserted into an egg cell from which most of the DNA has been removed (ScienceNOW, 19 June). But human egg cells are in short supply, and the donation process can cause serious side effects in women. To get around that problem, some researchers have tried nuclear transfer using a human cell and egg cells from rabbits or cows to produce so-called cytoplasmic hybrids, or cybrids. But none has been able to reliably produce ES cells. (There are no federal laws regulating such techniques in the United States as long as public funds are not used.)
Opinion polls commissioned by HFEA showed that the British public is deeply divided on the technique. A majority of people say they oppose combining human and animal DNA unless it is part of research specifically aimed at a disease such as ALS. In addition to the polls, HFEA held public meetings and commissioned panels of scientific experts to discuss the research and its implications. After considering all the opinions, officials announced today that "there is no fundamental reason to prevent" such research. But they said they will need to take a closer look at the two applications that have been submitted so far. Final decisions are expected in November.
Stephen Minger of King's College London in the U.K., who has submitted an application to try the technique in his lab, said in a statement that he welcomed today's decision. "The use of nonhuman oocytes for SCNT is currently the only ethically justifiable option given the large numbers of eggs required to derive cloned human stem cell lines," he said.