New compounds may aid in development of targeted therapies for a rare pediatric cancer

GRAND RAPIDS, Mich. (March 30, 2016)—Two recently discovered compounds have shown promise in preclinical studies for treating Ewing sarcoma, a rare cancer that predominantly affects children and adolescents.

Both compounds suppress the activity of EWS-FLI1, which belongs to a class of molecules called transcription factors that play key roles in gene regulation. In Ewing sarcoma, EWS-FLI1 switches certain genes “on” or “off” incorrectly, leading to uncontrolled cellular proliferation and, ultimately, tumors.  Although they are difficult to target for drug treatment because of their structure, transcription factors offer significant opportunities for developing more precise therapies that perform better and have fewer side effects.

“Our current approach—a combination of chemotherapy, radiation and surgery—is a tough road and isn’t extremely effective in patients whose cancer has spread or relapsed,” said senior author Patrick Grohar, M.D., Ph.D., an associate professor at Van Andel Research Institute and a pediatric oncologist at Spectrum Health Helen DeVos Children’s Hospital. “EWS-FLI1 is unique to Ewing sarcoma and is present in the majority of cases, which offers an excellent opportunity for developing precise therapies that combat cancer cells with less chance of affecting normal, healthy cells. At the same time, these findings lay the groundwork for devising ways to target transcription factors in other cancers, which historically has been challenging.”

The new compounds are derived from mithramycin, a drug previously investigated as a potential therapy for Ewing sarcoma. Not only do they suppress EWS-FLI1 activity more effectively than mithramycin, but the new compounds also demonstrate far less toxicity, making them attractive candidates for further studies.

“Although we are hopeful our findings will lead to new, more effective therapies for Ewing sarcoma, we also believe they serve as a precedent for targeting transcription factors in other tumor types,” Grohar said. “We’re excited to complete the preclinical work, which will help us prioritize one of the compounds for translation into a clinical trial.”

The study was published online in the journal Clinical Cancer Research and includes authors from EntreChem S.L., Vanderbilt University, National Cancer Institute, Frederick National Laboratory for Cancer Research, Washington University School of Medicine, The Ohio State University and Texas Tech University. Grohar also holds an academic appointment at Michigan State University College of Human Medicine.


Osgood CL, Maloney N, Kidd CG, Kitchen-Goosen S, Segars L, Gebregiorgis M, Woldemichael GM, He M, Sankar S, Lessnick S, Kang M, Smith M, Turner L, Madaj ZM, Winn ME, Núñez LE, González-Sabín J, Helman LJ, Morís F, Grohar PJ. In press. Identification of mithramycin analogs with improved targeting of the EWS-FLI1 transcription factor. Clin Cancer Res.


Van Andel Institute (VAI) is an independent nonprofit biomedical research and science education organization committed to improving the health and enhancing the lives of current and future generations. Established by Jay and Betty Van Andel in 1996 in Grand Rapids, Michigan, VAI has grown into a premier research and educational institution that supports the work of more than 350 scientists, educators and staff. Van Andel Research Institute (VARI), VAI’s research division, is dedicated to determining the epigenetic, genetic, molecular and cellular origins of cancer, Parkinson’s and other diseases and translating those findings into effective therapies. The Institute’s scientists work in onsite laboratories and participate in collaborative partnerships that span the globe. Learn more about Van Andel Institute or donate by visiting 100% To Research, Discovery & Hope®

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About Ewing sarcoma
Ewing sarcoma is a rare cancer that affects the bone or the tissues that surround the bone.

Current therapies for the disease include chemothe­rapy, radiation treatments or surgery, all of which can have a significant and lasting effect on quality of life, especially in children and adolescents. Unfortunately, this regimen is not effective for treating patients with relapsed or metastatic disease, necessitating the development of better, more targeted treatments.