Molecule boosts numbers of stem cells in umbilical cord blood

Advance means more transplant options could open up for cancer patients

READY FOR ACTION The molecule UM171 can increase the number of stem cells from stored umbilical cord blood, a new study shows. Stem cells extracted from cord blood and not treated with UM171 (left) appeared less robust than similar cells treated with UM171.

Institute for Research in Immunology and Cancer

By Kate Baggaley

September 18, 2014 at 5:02 pm

A newly created molecule multiplies stem cells in umbilical cord blood, researchers report in the September 19 Science. The finding brings the promise of more widespread use of cord blood in the treatment of blood cancers.

Currently only 5 percent of stored cord blood samples have enough stem cells for transplants. The new molecule has the potential to make up to 50 percent of cord blood units available for transplants, says study coauthor Guy Sauvageau, a hematologist and stem cell researcher at the Institute for Research in Immunology and Cancer in Montreal.

Stem cell transplants are used to treat blood diseases like leukemia and lymphoma, in which patients’ own blood-producing marrow has been obliterated by radiation or chemotherapy. Donated umbilical cord blood provides stem cells that can give rise to healthy, mature blood cells. Cord blood transplants often can be used in patients who cannot find an identical match for a bone marrow transplant. But the number of stem cells in cord blood tends to be low, so patients regenerate new blood slowly after a transplant, putting them at higher risk for infections.

“We think patients will benefit because they’ll recuperate faster and get better-matched transplants,” says Sauvageau.

Sauvageau and his colleagues combed through more than 5,000 lab-made molecules to see if any could increase stem cell counts in human cord blood. One small synthetic molecule stood out.

After Sauvageau and his team identified the molecule, they chemically modified it to make it more potent. They then treated cells from cord blood with the molecule, called UM171, which boosted the stem cell count to 13 times its original number, and transplanted the cells into mice. After six months, mice treated with UM171 were producing more human blood cells than mice that received untreated blood cells.

The researchers’ next goal is to figure out how UM171 works. They plan to start clinical trials with UM171 cord blood transplants in December.