Duke University A new research from Duke University Medical Center has apparently recognized a new growth factor that may fuel the growth and regeneration of hematopoietic stem cells in culture and in laboratory animals. The finding could aid scientists surmount one of the most exasperating obstructions to cellular therapy, the fact that stem cells are apparently so less in number and so obstinately opposed to expansion.

Study authors are of the opinion that umbilical cord blood could dole out a common source of stem cells for all patients who require a stem cell transplant, but the amounts of stem cells in cord blood units are restricted, so there could be a clinical need to build up a technique to enlarge cord blood stem cells for transplantation reasons.

John Chute, MD, a stem cell transplant physician and cell biologist at Duke and senior author of the paper, commented, “Unfortunately, there are no soluble growth factors identified to date that have been proven to expand human stem cells for therapeutic purposes.”

Chute, working with Heather Himburg, a post-doctoral fellow in his laboratory, found that including pleiotrophin, a naturally-occurring development factor, apparently fueled a ten-fold growth of stem cells extracted from the bone marrow of a mouse.

They also discovered that pleiotrophin seemingly augmented the amounts of human cord blood stem cells in culture that were said to be capable of engraftment in immune-deficient mice. When they inserted pleiotrophin into mice who were given bone marrow-suppressive radiation, they apparently noted a ten-fold augment in bone marrow stem cells as opposed to untreated mice.

Chute mentioned, “These results confirmed that pleiotrophin induces stem cell regeneration following injury.”

Chute mentioned that the discovery could result in wider application of cord blood transplants for the huge amounts of patients who apparently do not have an immune-matched donor.

Chute remarked, “Perhaps more importantly, systemic treatment with pleiotrophin may have the potential to accelerate recovery of the blood and immune system in patients undergoing chemotherapy or radiotherapy.”

Given the strength of the effect of pleiotrophin on stem cell expansion, the authors investigated whether pleiotrophin appeared to motivate blood-forming cells to turn malignant. Until now, apparently they had not observed any confirmation of cancer in mice up to six months following treatment with pleiotrophin.

The Duke team is already performing more experiments to find out if pleiotrophin could be essential for usual stem cell growth and development, and Chute mentioned that it could be vital to carry out added animal studies before moving into human clinical trials.

The research was published in the Journal Nature Medicine.