An embryonic stem cell line created from a woman with type 1 diabetes is a perfect genetic match for her. Photo: NYSCF/Reuters

And now there are three: in the wake of announcements from laboratories in Oregon and California that they had created human embryos by cloning cells of living people, a lab in New York announced that it had done that and more.

In addition to cloning the cells of a woman with diabetes, producing embryos and stem cells that are her perfect genetic matches, scientists got the stem cells to differentiate into cells able to secrete insulin.

That raised hopes for realising a long-held dream of stem cell research, namely, creating patient-specific replacement cells for people with diabetes, Parkinson’s disease, heart failure and other devastating conditions. But it also suggested that what the Catholic Church and other right-to-life advocates have long warned of – scientists creating human embryos to order – could be imminent.

The creation of human embryos for scientific experiments is certain

The trio of successes “increases the likelihood that human embryos will be produced to generate therapy for a specific individual,” said bioethicist Insoo Hyun of Case Western Reserve University School of Medicine in Cleveland. And “the creation of more human embryos for scientific experiments is certain”.

The accelerating progress in embryonic stem cell research began last May. Scientists, led by Shoukhrat Mitalipov of Oregon Health & Science University, reported they had created healthy, early-stage human embryos – hollow balls of about 150 cells – by fusing ova with cells from a foetus, in one experiment, and an infant in another.

In the latest study, published online in Nature, scientists led by Dieter Egli of the privately-funded New York Stem Cell Foundation Research Institute derived insulin-making ‘beta cells’ from the embryos they cloned from a 32-year-old with type 1 diabetes, an autoimmune disease in which the immune system attacks beta cells. Beta cells do not function in that incurable form of diabetes, often known as juvenile diabetes, which is treated with insulin.

The beta cells produce as much insulin as those in a healthy human pancreas, Egli said. When transplanted into lab mice, the cells functioned normally, making insulin in response to glucose.

Egli has no plans to transplant stem-cell-derived beta cells into patients with type 1 diabetes, in large part because the new cells will meet the same fate as the patient’s native beta cells.

It turns out that some cells produced this way self-destruct or die young, however, suggesting that the embryonic kind will be necessary after all.

That has resurrected a debate that flared in 2001, when US President George W. Bush declared that federal funds could not be used to create human embryos for research. Existing stem cell lines, or IVF embryos, were therefore used.