According to professors, Harvard researchers last week were dealt a humbling blow when a monumental medical breakthrough in stem cell research took place in a South Korean lab.

Last Thursday, South Korean scientists Dr. Woo Suk Huang and Dr. Shin Young Moon became the first to extract a line of stem cells from a cloned human embryo, clearing the first hurdle towards therapeutic cloning—a method aimed at treating diseases rather than making babies.

This landmark achievement in South Korea has brought into focus a fear that Harvard researchers have shared since 2000—namely, that one of the world’s leading institutions is lagging behind other countries in stem cell research.

“It’s a terrible disappointment that we’re reading about it from other countries,” says David T. Scadden, director of Massachusetts General Hospitals’s Center for Regenerative Medicine and Technology. “It’s imperative that we be able to use this technology in the U.S.”

Scadden says that Harvard plans to learn the details of the process used by the South Korean researchers, either by sending someone to South Korea or by reading the scientists’ eventual publication.

But he adds that the fear of falling behind is creeping into laboratories across the nation.

The road to therapeutic cloning in the U.S. is a bumpy one. The Bush administration’s 2001 decision to restrict federal funding for projects working with a small batch of preexisting stem cells elicited cheers from those who feel that destroying embryos for the sake of research is tantamount to murder.

But much of Harvard’s medical community say the restrictions impeded the advancement of science across the nation.

“Harvard scientists are a competitive lot,” says Dr. George Q. Daley, a stem cell specialist at Harvard Medical School (HMS). “Harvard is committed to moving science forward. We should be a leader in what could be one of the most revolutionizing fields of medicine.”

The practice of therapeutic cloning begins with ‘blank’ stem cells that are genetically identical to those of the patient.

Although minuscule in size, an embryonic stem cell’s ability to develop into any other kind of cell in the body is important for the future of medicine.

By prodding stem cells to become specialized cells and then implanting them into the patient to replace faulty tissue, doctors could cure debilitating conditions such as diabetes and Parkinson’s disease.

Daley says that Harvard scientists continue to do work with three of the dozen president-approved stem cell lines currently available for distribution.

However, given that even these stem cell lines are expensive to obtain, support from outside organizations is crucial for ambitious projects.

Some Harvard researchers have been able to use privately-funded work to circumvent Bush’s restrictions.

Dr. Douglas A. Melton, a molecular biologist at HMS, made headlines in 2003 when he announced that he had developed 17 embryonic stem cell lines, which he will make available for research this year.

But since Melton’s batch doesn’t meet the criteria for federal approval, any scientist wanting to use these stem cell lines will need private funding, which is hard to come by.

Even with financial support, experts agree that the ethics of cloning continue to make new projects controversial. Some critics deplore the destruction of embryos for the sake of research, which they equate to abortion.

But Louis M. Guenin, who teaches ethics in science at HMS, contends that experiments with discarded embryos from fertility clinics can lead to important medical treatments.

“It seems difficult to deny that relieving widespread suffering is morally better than destroying embryos at no gain,” Guenin says.

Like discarded embryos from fertility clinics, cloned embryos for research are not meant for implantation in the uterus, says Guenin, addressing concerns that the practice will lead to reproductive cloning.

“[Therapeutic cloning] is an avenue for the humanitarian relief of suffering,” he says.

But despite the benefits, some are still weary.

Dr. Walter Robinson, associate director of the Division of Medical Ethics at Harvard, says that the current regulation could push stem cell research to become commercialized. He says the major emphasis would become “the financial game instead of the open and free exchange of ideas.”

“Ultimately,” Robinson adds, “it becomes a competition on who gets to make the announcement first.”

Despite the continued debate over research, and South Korea’s significant breakthrough, Harvard scientists say they are excited by the progress in the field.

“I was very pumped,” Daley says, recalling his reaction to the news.

“It’s really a small technical breakthrough, one that we’ve done with mammals, but to finally do it with human embryonic stem cells...it’s remarkable.”

—Jackeline Montalvo can be reached at montalvo@fas.harvard.edu.