Hypoxia-driven hybrid phenotypes in Ewing sarcoma: Insights from computational epithelial-mesenchymal transition modeling

Ewing sarcoma (ES) is an extremely aggressive pediatric tumor primarily propelled by the EWS::FLI1 fusion protein. This fusion protein plays a pivotal role in various biological processes within ES, including hypoxia and epithelial-mesenchymal transition (EMT). Hypoxia has been documented to trigger EMT, a process that can stabilize a hybrid cell state, enhancing metastatic potential and resistance to drugs. However, the precise mechanisms that sustain this hybrid phenotype during hypoxia in ES have remained enigmatic. Our study introduces a logical model for EMT in ES, underscoring the potential significance of the EWS::FLI1/miR-145 circuit in inducing hybrid states during hypoxia. Furthermore, our findings underscore the necessity for downregulating EWS::FLI1 to fully activate EMT under hypoxic conditions. This model aligns well with results derived from existing literature. These insights underscore the crucial role of EWS::FLI1 in inducing the hybrid state in ES during hypoxia.