A small molecule blocking oncogenic protein EWS-FLI1 interaction with RNA helicase A inhibits growth of Ewing's sarcoma (original) (raw)

Many sarcomas and leukemias carry non-random chromosomal translocations encoding mutant fusion transcription factors that are essential to their molecular pathogenesis. These novel, tumorspecific proteins provides a unique opportunity for the development of highly selective anticancer drugs that has yet to be exploited. A particularly clear example is provided by Ewing's Sarcoma Family Tumors (ESFT) which contain a characteristic t(11;22) translocation leading to expression of the oncogenic fusion protein EWS-FLI1. EWS-FLI1 is a disordered protein that precluded standard structure-based small molecule inhibitor design. Using surface plasmon resonance screening, we discovered a lead compound, NSC635437. A derivative compound, YK-4-279, blocks RHA binding to EWS-FLI1, induces apoptosis in ESFT cells, and reduces the growth of ESFT orthotopic xenografts. These findings provide proof of principle that inhibiting the interaction of mutant cancer-specific transcription factors with the normal cellular binding partners required for their oncogenic activity provides a promising strategy for the development of uniquely effective, tumor-specific anticancer agents. There is a significant need for new cancer therapies that enhance efficacy and reduce longterm morbidity. Protein products of tumor-specific chromosomal translocations, which are present only in cancer cells, provide unique targets for anti-tumor therapies1. These translocations span a broad range of malignancies, including carcinomas, hematopoietic malignancies, and sarcomas2-4. In many cancers, these translocations lead to novel fusion proteins that both initiate and maintain oncogenesis. While some of these translocations, such as BCR-ABL5, lead to constitutively activated kinases, the majority lead to fusion proteins that function as transcription factors and lack intrinsic enzymatic activity. These translocation-generated transcription factor fusion proteins are ideal targets of anti-cancer therapies, yet no pharmaceuticals have been developed towards these targets. The Ewing's sarcoma family of tumors (ESFT) can occur anywhere in the body and most often in the 2 nd and 3 rd decades. ESFT often respond well to initial chemotherapy, yet 40% of patients will develop recurrent disease. The majority of patients with recurrent disease will die from ESFT, while 75-80% of patients who present with metastatic ESFT will die Users may view, print, copy, and download text and data-mine the content in such documents, for the purposes of academic research, subject always to the full Conditions of use: