Discovery may point to cell of origin for Ewing sarcoma

Elena Vasileva, PhD, and James Amatruda, MD, PhD (Photo courtesy of CHLA)

New study suggests that neural crest cells are reprogrammed into tumor-forming cells, reshaping the understanding of this childhood cancer.

For decades, scientists have been puzzled by two enduring mysteries around Ewing sarcoma. Why does this aggressive bone and soft tissue cancer mainly affect children and adolescents? And why do its tumor cells appear so primitive, showing features of multiple different cell types?

Now, Children’s Hospital Los Angeles researchers may have found answers to these questions. Their newly published study, a close collaboration with the Keck School of Medicine of USC, provides the first in vivo genetic evidence that Ewing sarcoma may originate from neural crest cells—flexible embryonic cells that normally give rise to neurons, glial cells, and pigment cells.

The team showed that a common mutation in this cancer—the EWSR1::FLI1 fusion oncogene—can reprogram neural crest cells into a mesoderm-like state, adopting features of bone- and muscle-forming cells. Results were published in Cell Reports – Opens in a new window.

“This is an exciting step forward in Ewing sarcoma research,” says James Amatruda, MD, PhD, Director of the Cancer and Blood Disease Institute at Children’s Hospital Los Angeles and senior author of the study. “By understanding where and how this disease begins, we open the door to developing more effective and less-toxic treatments.”

The work was the result of a collaboration between Dr. Amatruda’s team at CHLA and the laboratory of Gage Crump, PhD, Professor and Vice Chair of Stem Cell Biology and Regenerative Medicine at USC. Elena Vasileva, PhD, a postdoctoral fellow at CHLA, was the study’s first author.