Nav: Home

Not just a stem cell marker

January 22, 2018

A protein used to identify blood-forming cells is much more than a mere surface marker. A KAUST study shows that this protein, known as CD34, also plays a key role in binding adhesion molecules in the bone marrow.

The discovery that this binding aids in the proper engraftment of blood-forming stem and progenitor cells following their transplantation is a result that opens the door to "improving the migration of these cells for therapeutic endeavors," says Jasmeen Merzaban, the biochemist who led the team.

Stem cell transplants are used to treat patients with a variety of life-threatening blood disorders. These stem cells, when derived from an adult (as opposed to from cord blood), are isolated by giving the donor a drug that causes stem cells in the bone marrow to mobilize and enter the bloodstream. The blood is then run through a device that extracts all the cells expressing CD34.

These CD34-positive cells can give rise to all the various types of blood components--but they're not the only ones with this ability. Some cells that don't express this surface marker can do the same; however, CD34-negative cells in circulation aren't as good at finding their way to the bone marrow. Thus, doctors have tended to focus on CD34 selection as an easy and effective means of enriching for high-potential blood stem and progenitor cells despite the longstanding mystery of the normal biological function of CD34.

Merzaban and her colleagues revealed one of the functions of this protein by first testing different populations of blood-forming cells for their ability to bind adhesion molecules. They showed that only those cells expressing CD34 could do so, and an unbiased protein screen revealed that CD34 itself was responsible for this binding. Knocking down the protein confirmed CD34's essential role in cell migration.

According to the study's first author, Dina AbuSamra, a former doctoral student in Merzaban's lab now at Harvard Medical School, the results have therapeutic implications beyond simply understanding transplantation. As she points out, the CD34 protein that's found on the surface of leukemic stem cells is different from the one on healthy blood-forming stem cells. There is potential to exploit this difference "to identify leukemic stem cells and, in theory, target them using various approaches," AbuSamra says.

Merzaban also suggests that CD34-negative blood-forming stem cells--a population currently overlooked in transplantation medicine--could be manipulated in ways that boost their binding abilities. Adding these cells to the CD34-positive population might collectively augment overall efficiencies of the procedure, leading to long-term success following transplants. "This is currently a major focus of our lab," Merzaban says.
-end-


King Abdullah University of Science & Technology (KAUST)

Related Stem Cells Articles:

A protein that stem cells require could be a target in killing breast cancer cells
Researchers have identified a protein that must be present in order for mammary stem cells to perform their normal functions.
Approaching a decades-old goal: Making blood stem cells from patients' own cells
Researchers at Boston Children's Hospital have, for the first time, generated blood-forming stem cells in the lab using pluripotent stem cells, which can make virtually every cell type in the body.
New research finds novel method for generating airway cells from stem cells
Researchers have developed a new approach for growing and studying cells they hope one day will lead to curing lung diseases such as cystic fibrosis through 'personalized medicine.'
Mature heart muscle cells created in the laboratory from stem cells
Generating mature and viable heart muscle cells from human or other animal stem cells has proven difficult for biologists.
Mutations in bone cells can drive leukemia in neighboring stem cells
DNA mutations in bone cells that support blood development can drive leukemia formation in nearby blood stem cells.
Scientists take aging cardiac stem cells out of semiretirement to improve stem cell therapy
With age, the chromosomes of our cardiac stem cells compress as they move into a state of safe, semiretirement.
Purest yet liver-like cells generated from induced pluripotent stem cells
A team of researchers from the Medical University of South Carolina and elsewhere has found a better way to purify liver cells made from induced pluripotent stem cells.
Stem cell scientists discover genetic switch to increase supply of stem cells from cord blood
International stem cell scientists, co-led in Canada by Dr. John Dick and in the Netherlands by Dr.
Stem cells from diabetic patients coaxed to become insulin-secreting cells
Signaling a potential new approach to treating diabetes, researchers at Washington University School of Medicine in St.

Related Stem Cells Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Digital Manipulation
Technology has reshaped our lives in amazing ways. But at what cost? This hour, TED speakers reveal how what we see, read, believe — even how we vote — can be manipulated by the technology we use. Guests include journalist Carole Cadwalladr, consumer advocate Finn Myrstad, writer and marketing professor Scott Galloway, behavioral designer Nir Eyal, and computer graphics researcher Doug Roble.
Now Playing: Science for the People

#529 Do You Really Want to Find Out Who's Your Daddy?
At least some of you by now have probably spit into a tube and mailed it off to find out who your closest relatives are, where you might be from, and what terrible diseases might await you. But what exactly did you find out? And what did you give away? In this live panel at Awesome Con we bring in science writer Tina Saey to talk about all her DNA testing, and bioethicist Debra Mathews, to determine whether Tina should have done it at all. Related links: What FamilyTreeDNA sharing genetic data with police means for you Crime solvers embraced...