The foreseeable future of embryonic stem cell research hinges on a court’s ruling set to come Monday, Sept. 27.

Nationwide, researchers with freezers full of human embryonic stem cells are waiting to hear whether the United States Court of Appeals will allow funding to flow to their projects or if they’ll need to be put on hold.

In August, Judge Royce Lamberth ruled that no embryonic stem cell research could receive federal funding while the case is ongoing. Earlier this month, the Court of Appeals temporarily lifted the ban until opponents of embryonic stem cells and researchers argued their cases.

If the ban is upheld, it will last at least until Lamberth’s case concludes, which could be years.

Among those waiting is Dr. Jonathan Slack, director of the Stem Cell Institute at the University of Minnesota. Slack and some 30 faculty at the University have anxiously watched as the debate over federal funding for their research has gone back and forth in the past one and a half years.

There are five ongoing projects that use human embryonic stem cells at SCI, Slack said. Each of those projects — from efforts to create blood-forming cells that might be used in cancer therapy, to muscle-building cells that could combat muscle dystrophy — would be in jeopardy if the court rules that funding must be halted.

Human embryonic stem cells are cells harvested from embryos donated by parents at in vitro fertilization clinics that would be thrown away if not used for research. These cells can transform into nearly every type of cell in the body and could be useful in treating diabetes, cancer and other serious diseases, scientists believe.

“If [funding] were terminated, there’s no way we could find enough private funding to take them over,” Slack said, guessing the five projects add up to $2 million in costs annually. “There’s no way you can replace that magnitude of funding.”

Things seemed to be looking up for Slack and his colleagues in March 2009 when President Barack Obama opened the doors by signing an executive order to permit the creation of new stem cell lines, which had been restricted by President George W. Bush since 2001.

Though it didn’t create more funding for research and added just a few dozen more stem cell lines, “it sent the signal around the world that the U.S.A. was serious about stem cell research,” Slack said.

Embryonic stem cell research is legal throughout much of Western Europe and Canada, though several countries outlaw the creation of embryos for research.

Judge Lamberth, U.S. district judge for the District of Columbia, cited the 1996 Dickey-Wicker Amendment — which prohibits federal funding from being used in research in which an embryo is destroyed — in his August decision.

“If one step or ‘piece of research’ of an embryonic stem cell research project results in the destruction of an embryo, the entire project is precluded from receiving federal funding,” Lamberth wrote in his ruling.

Following an outcry from the scientific community, that ruling was stayed by the Court of Appeals until it could hear arguments from both sides. The court will decide whether to allow funding to continue pending Lamberth’s final ruling or to continue his preliminary ban.

Opponents argue that the use of embryonic stem cells is unethical and that their benefits are unproven. Adult stem cells — typically harvested from the umbilical cord without damage to a newborn — have proven valuable in medicine.

But many scientists argue embryonic stem cells could prove far more valuable with time. Unlike embryonic stem cells, adult stem cells cannot divide indefinitely or morph into nearly as many different cell types, said Francis Collins, director of the National Institutes of Health.

Collins testified before the Senate Subcommittee of Labor, Health and Human Services last week to stress the importance of embryonic stem cell research.

“If the government is not successful in defending the guidelines in this litigation, and NIH will have to withdraw future NIH support for all grants involving human embryonic stem cell research, drastic scientific consequences will occur,” Collins said.

NIH is responsible for all federal funding of stem cell research, and has invested more than $500 million in embryonic stem cell projects, Collins said.

Slack guessed the majority of research projects nationwide that use embryonic stem cells actually deal with induced pluripotent stem cells, a third type of cell which can be created from a patient’s skin cells.

Researchers inject new genes into the skin cells, instructing them to divide and morph into new cell types like embryonic stem cells, which researchers need to use as a comparison to make sure the new cells function correctly.

“Much of that will be caught up in this injunction, and I certainly don’t think that was Judge Lamberth’s intention,” Slack said.