A specific genetic alteration has been identified as a defining feature of epithelioid hemangioendothelioma (EHE), an uncommon vascular sarcoma that strikes approximately 100 people in the United States each year. Although EHE can appear anywhere in the body, common sites are the liver, the lungs, and the bone. Some EHE tumors remain stable for years, whereas others grow rapidly and can be fatal.
Researchers defined the genetic aberration as a translocation between chromosomes 1 and 3: The chromosomes exchanged DNA fragments in such a way that the DNA is transposed onto opposite chromosomes, resulting in a unique, fused gene that contains components from each chromosome. The interaction of the two genes—WW domain-containing transcription regulator 1 (WWTR1) and calmodulin-binding transcription activator 1 (CAMTA1) creates a corresponding protein whose function appears to be oncogenic.
The gene fusion was present in virtually all EHEs tested (42 of 47, or 89%), but was absent from all other vascular neoplasms.
“This finding is the beginning of a new era for patients with EHE,” commented study leader Brian P. Rubin, MD, PhD, of the Cleveland (Ohio) Clinic’s Pathology and Laboratory Medicine Institute and Lerner Research Institute, in a study announcing his team’s findings. “We firmly believe that the characterization of this genetic translocation will lead to a cure for EHE patients.”
The research was published in Science Translational Medicine (2011;3:98ra82).