Blood stem cells are a vital part of us. They create all the other kinds of blood cells in our body and are used in bone marrow transplants to help people battling leukemia or other blood cancers. The problem is growing these blood stem cells outside the body has always proved challenging. Up till now.

Researchers at UCLA, with CIRM funding, have identified a protein that seems to play a key role in helping blood stem cells renew themselves in the lab. Why is this important? Because being able to create a big supply of these cells could help researchers develop new approaches to treating a wide array of life-threatening diseases.

One of the most important elements that a stem cell has is its ability to self-renew itself over long periods of time. The problem with blood stem cells has been that when they are removed from the body they quickly lose their ability to self-renew and die off.

To discover why this is the case the team at the Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research at UCLA analyzed blood stem cells to see which genes turn on and off as those cells turn into other kinds of blood cells – red, white and platelets. They identified one gene, called MLLT3, which seemed to play a key role in helping blood stem cells self-renew.

To test this finding, the researchers took blood stem cells and, in the lab, inserted copies of the MLLT3 gene into them. The modified cells were then able to self-renew at least 12 times; a number far greater than in the past.

Dr. Hanna Mikkola, a senior author of the study says this finding could help advance the field:

“If we think about the amount of blood stem cells needed to treat a patient, that’s a significant number. But we’re not just focusing on quantity; we also need to ensure that the lab-created blood stem cells can continue to function properly by making all blood cell types when transplanted.”

Happily, that seemed to be the case. When they subjected the MLLT3-enhanced blood stem cells to further analysis they found that they appeared to self-renew at a safe rate and didn’t multiply too much or mutate in ways that could lead to leukemia or other blood cancers.

The next steps are to find more efficient and effective ways of keeping the MLLT3 gene active in blood stem cells, so they can develop ways of using this finding in a clinical setting with patients.

Their findings are published in the journal Nature.