Harvard scientists announced today they are beginning an ambitious attempt to create the worlds first cloned human embryonic stem cells, bringing the university into one of sciences most ethically charged fields.
The goal of the research, they said, is to create a powerful new tool to explore the biology of, and hopefully find treatments for, a number of devastating diseases: juvenile diabetes, genetic blood disorders, and ALS, also known as Lou Gehrigs disease.
The research is controversial because scientists destroy days-old embryos, which critics say means taking human lives, and because the research uses human eggs, and this can place women donors at a slight risk of suffering side effects.
But at a press conference today, Harvard Provost Dr. Steven E. Hyman said the university had concluded that the research was ethically justified, following an extensive set of reviews. The scientists will be required to follow a strict set of guidelines, he said, but the work is too important to not do.
We are convinced that work with embryonic stem cells holds enormous promise for developing treatments for a host of presently intractable adult and childhood diseases, Hyman said. We have approved this work after the most extensive ethical and scientific review in recent memory here at Harvard.
The announcement represents a high-profile boost for a field marred by scandal. In 2004, Korean scientist Hwang Woo Suk claimed he had created the first cloned human embryonic stem cells, raising the hopes of patients and bringing world-wide attention. By the end of 2005, his claim had collapsed in a dramatic case of scientific fraud, leaving scientists to wonder whether the technically challenging feat is even possible.
But now at least eight teams outside of Harvard have said they will attempt to create cloned human stem cells, but the Harvard project is particularly large, with two independent teams of top scientists -- one at Harvard University, one at Childrens Hospital Boston -- each working with their own network of collaborators. Several of the other teams are behind Harvard.
The project also constitutes a statement from Harvard, an institution that generally shies from controversy, that it intends to aggressively pursue a course set by outgoing president Lawrence H. Summers. Summers has been a champion of the Harvard Stem Cell Institute, arguing that stem cell technology will prove to be an enduring force in science, medicine and business -- and that researchers from across the sprawling institution should cooperate to make Harvard a world leader in it. The cachet of the Harvard name will mean that the project will draw close attention, both from advocates and critics of the work.
Although cloning has been used successfully in many animals, each species presents a unique set of technical challenges, requiring changes in the technique. Because the procedure has never been done successfully with human cells, nobody knows how difficult it will be, or how long it will take, scientists said.
Embryonic stem cells have the ability to become virtually any cell in the body, making them a valuable tool in scientific research. Typically, embryonic stem cells are generated from frozen early embryos -- microscopic balls of several hundred cells -- which fertility clinics plan to discard. But cloning, also called somatic cell nuclear transfer, would make it possible to create embryonic stem cells that have the same DNA as a patient with a particular disease.
To do this, the Harvard scientists plan to extract DNA from a patients cells and place it into a donated egg cell that has had its own DNA removed. This new cell is then prompted to grow for several days in a laboratory dish, yielding the early embryo needed for embryonic stem cells. These cloned stem cells can then be grown in the lab and in theory be manipulated to become different types of human tissue, such as the neurons that make up the brain.
Researchers could then compare the development of neurons made with the diseased embryonic stem cells to neurons made with embryonic stem cells produced with the DNA from a person without the disease. Finding these differences could reveal the inner workings of the disease, and perhaps suggest drugs or other therapies to treat it.
Scientists still dont know how to coax embryonic stem cells to become many types of tissue.
The embryos will be used to create cells only, not cloned babies -- a step that would be biologically challenging to take, and that virtually all scientists would find abhorrent. Using nuclear transfer for reproduction is a crime under a Massachusetts law passed last year. The law makes it legal to do nuclear transfer and other forms of stem cell research.
Nuclear transfer has complicated the debate over embryonic stem cell research. Most of the opposition to embryonic stem cell research in this country has come from political conservatives who object to the destruction of human embryos. But nuclear transfer has also generated criticism from liberal, abortion rights activists, who do not think that female volunteers should be subjected to the risks involved in egg extraction for research, whose benefits cant be predicted.
The merit isnt such that these women should be asked to undergo these risks, said Judy Norsigian, executive director of Our Bodies Ourselves. Norsigian supports other forms of embryonic stem cell research.
Egg extraction is commonly used in the fertility business. Donors are given drugs to stimulate their ovaries to produce many eggs. This is time-consuming and can be uncomfortable. The process can also have side effects, including ovarian hyperstimulation syndrome, a dangerous condition that is serious in about one percent of women getting fertility treatment.
The work is also complicated because it cannot be supported with federal money. In 2001, President George W. Bush prohibited the government from funding any research that would create new batches of embryonic stem cells, though scientists can use federal money to work with embryonic stem cells created before the policy. Last year, the U.S. House of Representatives approved legislation that would ease the rule, but the legislation does not permit funding of nuclear transfer, and the Senate has yet to vote on it.
The scientists leading the research are Douglas Melton and Kevin Eggan of Harvard University, and Dr. George Q. Daley of Harvard Medical School and Childrens Hospital Boston.