Establishment and characterization of a novel patient-derived Ewing sarcoma cell line, NCC-ES2-C1.

Ewing sarcoma (ES) is a small round cell sarcoma that is characterized by the unique gene translocation EWSR1-FLI1. It is the second most common primary bone and soft tissue malignancy in children and adolescents. It constitutes 10-15% of all bone sarcomas and is highly aggressive and rapidly recurring. Although intensive treatments have improved the clinical outcome of ES patients, 20-25% of them exhibit metastases during diagnosis. Thus, the prognoses of these patients remain poor. Cell lines are pivotal resources to investigate the molecular background of disease progression and to develop novel therapeutic modalities. In this study, we established and characterized a novel ES cell line, NCC-ES2-C1. The presence of the EWSR1-FLI1 fusion gene in these cells was confirmed in the NCC-ES2-C1 cells. Furthermore, these cells exhibited constant proliferation, and invasion, but did not form tumors in mice. We screened the anti-tumor effects of 214 anti-cancer drugs in NCC-ES2-C1 cells and found that the drugs which effectively reduced the proliferation of NCC-ES2-C1 cells. We concluded that NCC-ES2-C1 cells are a useful resource to study functions of the EWSR1-FLI1 fusion gene, investigate phenotypic changes caused by genes and proteins, and evaluate the anti-tumor effects of novel drugs.