As the Obama administration prepares to greatly expand the government’s investments in embryonic stem cell research, the next big biomedical research debate in Congress is shaping up: whether to allow government funding of experiments using cloned human embryos.

Two House members who were the chief backers of legislation to expand embryonic stem cell research are working on a new bill that would codify President Obama’s recent executive order allowing greater federal funding for the research. Their legislation will also contain language allowing the National Institutes of Health to invest in other kinds of research into human cell biology, perhaps including what is known as “therapeutic cloning.”

Some scientists were disappointed April 17 when the NIH issued draft guidelines for embryonic stem cell research that excludes from federal funding cell lines developed using a procedure called “somatic cell nuclear transfer,” or SCNT. Synonymous with therapeutic cloning, the procedure could theoretically yield stem cells from human embryos that are genetic copies of adults.

Experts in the field believe that therapeutic cloning could one day lead to advances such as tissue transplants that carry no threat of rejection by a patient’s immune system. SCNT could also be used to reproduce tissue affected by poorly understood diseases like Alzheimer’s or Parkinson’s, allowing scientists to study the genetic underpinnings of the conditions, said Dr. Irving Weissman, director of Stanford University’s stem cell research center.

Weissman issued a statement April 17 blasting the NIH’s proposal to exclude SCNT from funding. “The hope, for me, is to get at diseases that we watch kill people and we can do nothing about,” Weissman said.

Rep. Diana DeGette , D-Colo., who is drafting the new stem cell research legislation with Rep. Michael N. Castle , R-Del., said that she does not seek to order the NIH to fund research based on therapeutic cloning. But she hopes to encourage it.

“I hope the NIH will allow SCNT to move forward with federal funding,” DeGette said. “But if they don’t do that right now, what our bill will do is allow them to change that in the future if research shows it is a necessity and can be done ethically.”

Ethical Questions Arise

But stem cell scientists like Weissman have a much different view of what is ethical than do social conservatives, who liken embryonic stem cell research to abortion because it requires the destruction of embryos. The National Right to Life Committee, an anti-abortion group, sent a letter to Congress March 31 warning that the DeGette-Castle legislation will be a “bait-and-switch,” using obscure language to conceal its intent to authorize funding for cloned embryonic stem cells.

“They know that the American public is strongly against human cloning, so they hope to empower NIH to engage in it through subterfuge,” said Douglas Johnson, legislative director for the committee.

The NIH’s draft guidelines were intended to spell out what kinds of embryonic stem cell research it will support, in the wake of a March 9 executive order by President Obama that ended the George W. Bush administration’s strict limits on funding of the research.

However, the NIH says even now that it will only fund research involving embryonic stem cells derived from embryos discarded by in vitro fertilization clinics, and only in cases where the parents of the embryos consent in writing to their use for science. Embryonic stem cells derived from other means, including somatic cell nuclear transfer, will not be eligible for federal funding.

A law known as Dickey-Wicker, which has been renewed annually as part of the regular appropriations process, forbids federal funding for the creation of embryonic stem cells, including cloned cells, because the process destroys embryos. But both Obama and Bush have interpreted Dickey-Wicker to allow the funding of research using the cells.