Ionizing radiation exposure promotes fusion oncogene formation

The accident at the Chernobyl nuclear power plant exposed hundreds of thousands of individuals to high levels of ionizing radiation. In the years immediately following the disaster, there was a sharp increase in the number of papillary thyroid cancers (PTC) in patients that were children at the time of the explosion.

In this issue of the Journal of Clinical Investigation, James Fagin and colleagues at Memorial Sloan-Kettering Cancer Institute, examined tissues from Ukrainian PTC patients that were children at the time of the Chernobly catastrophe and identified their cancer-driving mutations.

The authors found that the majority of patient tumors had chromosomal rearrangements that resulted in fusion oncogenes. Many of these fusion events promoted upregulation of MAPK signaling, which is a common cancer-associated pathway. In contrast, fusion oncogenes were less common in PCT tumors from patients from the same geographical region, but had not been exposed to radiation.

In the accompanying commentary, Massimo Santoro and Francesca Carlomagno of the University of Naples discuss how this study provides new insight into how ionizing radiation exposure promotes cancer development.