Breakthrough in Bone Marrow Transplantation

Revolutionary method developed by an international team of scientists—led by Dr. Tomer Itkin from the Sagol Center for Regenerative Medicine at Tel Aviv University—promises to transform the field of bone marrow transplantation. This innovative approach allows for the multiplication of adult stem cells up to fivefold, offering new hope to patients requiring transplants but lacking sufficient donor matches.

Published in Nature Immunology, the research addresses one of the greatest challenges in bone marrow transplantation: the limited availability of suitable and sufficient donor stem cells. Patients with blood cancers, autoimmune diseases, or rare genetic conditions often struggle to find genetically compatible donors, and even when matches are found, extracting enough stem cells for effective treatment remains difficult.

Dr. Itkin, in collaboration with researchers from Sheba Medical Center and leading institutions worldwide—including Cornell University, Mount Sinai Hospital, the University of Toronto, and the Fred Hutchinson Cancer Research Center—developed a method to stimulate stem cells using modified mRNA technology (similar to that used in COVID-19 vaccines). This method activates a key protein, FLI-1, which controls the communication between stem cells and their supporting vascular cells. The result: controlled, temporary stimulation of stem cell division, without the risk of uncontrolled cell growth or cancer.

“To successfully transplant stem cells into an adult, you need about three million cells per kilogram of body weight,” explains Dr. Itkin. “That’s nearly 270 million cells for a 90 kg adult—numbers that are often impossible to reach with current techniques.”

The team's major insight was identifying FLI-1 as a "switch" that governs whether stem cells remain dormant or become active. By using modified mRNA to activate this switch in a controlled lab environment, the researchers were able to multiply the number of viable stem cells significantly. The expanded cells showed enhanced ability to regenerate blood and immune systems when tested in animal models.

This advancement could dramatically expand the pool of usable stem cells, not only reducing dependency on rare donor matches but also enabling new forms of therapy for patients undergoing repeated chemotherapy, or those with genetically corrected stem cells.

As Dr. Itkin summarizes:

“This isn’t just about making more cells—it’s about programming them to behave in ways that improve patient outcomes. The next step is translating this into clinical trials and expanding it to regenerate other tissues, even those lacking mature stem cells, like the heart.”

As a member of the Sagol Center for Regenerative Medicine, Dr. Itkin is contributing to a growing body of work positioning Israel at the forefront of cutting-edge regenerative therapies. The next step for the research team is to move into clinical trials, with the ultimate goal of bringing this technology to patients in need around the world.