In a bed-side to bench approach, researchers at Cincinnati Children's Hospital Medical Center report Sept. 26 in Nature Medicine that pharmacological inhibition of a signaling pathway triggered by Egfr (epidermal growth factor receptor) increased the mobilization of hematopoietic stem cells in mice. The finding provides a scientific basis for enhancing the effectiveness of autologous bone marrow transplants, in which the recipient donates his or her own stem cells prior to the procedure.
"Up to 10 percent of bone marrow donors fail to mobilize sufficient numbers of stem cells, which impedes autologous transplants and significantly delays transplant recovery time," said Hartmut Geiger, Ph.D., a researcher in the division of Experimental Hematology/Cancer Biology at Cincinnati Children's and senior investigator on the study. "Our findings reveal a new rationale for targeted pharmacological approaches to improve stem cell mobilization and transplantation outcomes."
Autologous bone marrow transplant is often used to restore a person's hematologic system after receiving radiation therapy for cancer treatment. Radiation exposure damages the system, which produces all of the body's blood cell types – including those vital to immune system function.
In clinical hematopoietic stem cell (HSC) transplants, the preferred source for mobilizing hematopoietic stem cells from bone marrow into peripheral circulating blood is by targeting a signaling protein called granulocyte colony stimulating factor, or G-CSF. G-CSF stimulates bone marrow so that it releases HSCs into circulating peripheral blood. Mobilization failures and delayed recovery rates suggest the need for a deeper molecular understanding of the mobilization process to further improve the treatment.
This prompted Dr. Geiger and his colleagues to search for therapeutic targets that would boost stem cell mobilization. They work with specially bred mice (recombinant inbred mice) in their research because much of the current knowledge about cellular and molecular regulation of G-CSF-induced stem cells comes from mouse studies. Because the G-CSF process that mobilizes hematopoietic stem and progenitor cells is conserved through evolution between mice and humans, inbred mouse strains are valuable surrogates for studies that can be translated to people.
Working from their previously published research, the scientists were able track a region on chromosome 11 in their mouse models that regulates G-CSF-induced mobilization of HSCs. Of 12 genes located in this region, testing pointed to Egfr, which is a protein involved in triggering molecular reactions that regulate cell growth, multiplication and migration. Mutations in Egfr have also been linked to cancer.
The researchers tested the G-CSF/Egfr pathway's influence on stem cell mobilization in several ways, including genetic manipulation and pharmacologic intervention. In one key experiment, involving mice undergoing bone marrow transplant, the researchers used an anti-cancer drug (Erlotinib) that blocks the Egfr pathway to enhance HSC mobilization. These mice experienced a 5-fold increase in stem cell mobilization.
"This suggests a possible application of these findings into the clinic," Dr, Geiger said. "Experiments are already planned to test whether this novel treatment for enhancing HSC mobilization might translate into novel therapies for patients."
First author on the study was Marnie A. Ryan, a research fellow of Dr. Geiger's laboratory team.
Funding support came from the National Institute of Health (NIH) through multiple grants and the Translational Research Initiative at Cincinnati Children's Hospital Medical Center.
Other institutions collaborating on the study include: the department of Dermatology and Allergic Diseases, University of Ulm, Ulm, Germany; Institute of Molecular and Clinical Immunology, Otto von Guericke University, Magdeburg, Germany; department of Biological Sciences, Eastern Kentucky University, Richmond, Ky.; department of Internal Medicine, Markey Cancer Center, Division of Hematology/Oncology, University of Kentucky, Lexington, Ky., and the Hoxworth Blood Center, University of Cincinnati College of Medicine.
About Cincinnati Children's
Cincinnati Children's Hospital Medical Center is one of just eight children's hospitals named to the Honor Roll in U.S. News and World Report's 2010-11 Best Children's Hospitals. It is ranked #1 for digestive disorders and highly ranked for its expertise in pulmonology, cancer, neonatology, heart and heart surgery, neurology and neurosurgery, diabetes and endocrinology, orthopedics, kidney disorders and urology. Cincinnati Children's is one of the top two recipients of pediatric research grants from the National Institutes of Health. It is internationally recognized for quality and transformation work by Leapfrog, The Joint Commission, the Institute for Healthcare Improvement, the federal Agency for Healthcare Research and Quality, and by hospitals and health organizations it works with globally.
Transport of molecular motors into cilia
28.03.2017 | Aarhus University
Asian dust providing key nutrients for California's giant sequoias
28.03.2017 | University of California - Riverside
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
28.03.2017 | Life Sciences
28.03.2017 | Information Technology
28.03.2017 | Physics and Astronomy