IU stem cell researcher gets special grant to explore interactions of novel molecule

INDIANAPOLIS -- (May 03, 2013) -- An Indiana University School of Medicine researcher has been awarded a research grant offered by the world’s largest professional hematological organization to augment a decrease in National Institutes of Health grants.

Edward F. Srour, Ph.D., a professor of medicine, pediatrics, and microbiology and immunology, is one of 17 researchers nationwide to receive an inaugural American Society of Hematology Bridge Grant of $100,000 each. Dr. Srour also is the Robert J. and Annie S. Rohn Professor of Leukemia Research at the Indiana University Melvin and Bren Simon Cancer Center and a member of the Herman B Wells Center for Pediatric Research.

The American Society of Hematology in July announced its commitment of $9 million over a three-year period to provide resources for the continuation of important, yet unfunded, biomedical research.

Dr. Srour’s research seeks to better understand the relationship between hematopoietic stem cells and their microenvironment and how to increase the clinical usefulness of these blood stem cells available for treatment of diseases such as cancer and autoimmune disorders. Hematopoietic stem cells are small in number compared to other blood cells, perhaps 1 in 100,000 or fewer. All blood cell types are derived from these stem cells.

In order to have enough stem cells for research projects, the number available has to be increased or enriched. Scientists use antibodies that recognize certain surface molecules on stem cells to identify them for collection in research. However, the research process has been complicated by the fact that markers on mouse stem cells and those on human stem cells are not the same.

In addition, the process of identifying and separating stem cells has not been foolproof. Isolation of stem cells is not absolute, yielding populations containing other types of blood cells.

In earlier collaborative research with Melissa KacenaPh.D., assistant professor of orthopaedic surgery, Dr. Srour found a molecule, CD166, present on both mouse and human stem cells. The molecule also helps purify research samples by further improving the identification of stem cells.

“The reason this molecule is exciting is that, unlike the others identified, this one is functional,” Dr. Srour said. “If CD166 is not present on the surface of the stem cell, the cell loses its function.”

Another important factor is that CD166 is also present on osteoblasts, the cells responsible for the formation of new bone. Osteoblasts are important building blocks of the hematopoietic microenvironment and are critical in the process of self-renewal and maintenance of hematopoietic stem cells. However, little is known about molecules that mediate or control interactions between osteoblasts and stem cells.

“This is the first molecule identified on stem cells of mice and humans and on cells in the microenvironment that are critical for the survival of stem cells,” Dr. Srour said.

The ASH Bridge Grant will allow Dr. Srour to better understand the role of CD166 in interactions between stem cells and osteoblasts and how these interactions contribute to the function and survival of the stem cell. With those answers, Dr. Srour hopes his project will receive NIH funding in the future.

A member of the IU School of Medicine research faculty since 1986, Dr. Srour says federal grant funding over the past four or five years has been the tightest he has experienced. There have been other ups and downs in availability of grant monies, but this stretch is the longest and tightest he recalls.

The $100,000 ASH Bridge Grants are designed to allow scientists, whose proposals have great merit but did not make the funding cut from the National Institutes of Health, to continue their biomedical research. The grant will provide a cushion to allow for additional laboratory discoveries to strengthen the researchers’ chances of obtaining federal funding.

According to the American Society of Hematology, the NIH has had a decade of flat funding and, after adjustment for inflation, award dollars are nearly 20 percent lower today than in 2003.