Blood from stem cells and other scientific picks from Alan Trounson

Each month CIRM President Alan Trounson gives his perspective on recently published papers he thinks will be valuable in moving the field of stem cell research forward. This month’s report, along with an archive of past reports, is available on the CIRM website.

CIRM President Alan Trounson discusses two recent advances in generating blood from stem cells, plus other notable discoveries from the previous month

My full report this month has two more examples of how reprogrammed stem cells (iPS cells) could earn all the praise they garnered when their discover won the Nobel Prize in October. In one, researchers succeeded in using them to replace myelin, the insulating cells that protect nerves, but are lost in multiple sclerosis. In another, a research team created iPS cells from four Alzheimer’s disease patients and used them to divide the patients into subsets that could help define which ones will respond to certain therapies.

But I want to devote this blog to a pair of studies that made significant advances in an area that has frustrated researchers for years: how to grow blood-forming stem cells outside the body in large quantities. This roadblock has created significant limitations on the use of blood stem cell transplants for leukemia, other blood-system cancers and blood conditions like sickle cell disease. It has made the transplant procedure more onerous for patients and donors as more cells must be harvested and created major limitations on the use of umbilical cord blood.

One team at the University of Texas, Southwestern, has shown that blood forming stem cells reside in different neighborhoods of the bone at different times in their path from stem cell to mature blood cell, with white blood cells passing through different neighborhoods than red cells, etc. The group hopes to complete a map of the environments that foster stem cell growth and maturation with the hope of learning how to replicate the factors in those bone marrow niches, or neighborhoods, in the lab.

Another team, funded by CIRM, looked at the current techniques used to try to grow blood-forming stem cells in the lab and make those more reflective of the natural niche in the bone marrow. Researchers typically grow blood-forming stem cells on layers of cells formed from the second type of stem cell found in bone marrow, mesenchymal stem cells. But the cells they use tend to be a mix of several types of cells. When they isolated a single specific type of cell to use as the base for growing blood-forming cells, they got robust growth of the stem cells, much more than previously seen.

Taken together, these two papers suggest that in the relatively near future, blood stem cell transplants can become more widely available, less onerous, and probably safer.

My full report is available online, along with links to my reports from previous months.

A.T.