A group of researchers from the Stowers Institute for Medical Research have developed a new technique that can expand stem cells, greatly increasing the number of cells available for transplants. This new technology is particularly useful for cord blood stem cell transplants, where the available sample sizes are usually quite small.
The number of human umbilical cord blood (hUCB) transplants occurring each year continues to increase. Cord blood is often used to treat cancer, immune system disorders, blood disorders, and a variety of metabolic disorders.
Because umbilical cord stem cells are “young” cells, they are less likely to trigger an immune system reaction in the recipient. This makes them a safer option than bone marrow stem cells in many cases.
Unfortunately, using cord blood stem cells does have a downside. The size of the sample that can be obtained is usually quite small. This means doctors often have to find multiple sources of compatible cord blood samples. It can also mean the recovery time after a cord blood transplant is longer, as it takes more time for the small stem cell sample to develop within the patient’s body.
The research team that developed this new technique began by pinpointing a protein which changes the renewal process of the hematopoietic stem cells in cord blood. The protein, called Ythdf2, encodes certain transcription factors important for self-renewal.
The researchers began testing how changes to Ythdf2 would affect the hematopoietic stems cells found in hUCB. They found that impairing function of Ythdf2 had no ill effects, but caused the stem cells to self-renew faster.
Being able to expand stem cells would allow doctors to make large samples from a relatively small number of umbilical cord stem cells. This will help the thousands of people who rely on stem cell transplants each year.