Characterisation of Bespoke Patient-Derived In Vitro Models of Ewing Sarcoma

Area of Science:

• Oncology
• Cancer Biology
• Translational Research

Background:

• Accurate preclinical models are crucial for Ewing sarcoma (ES) targeted therapy development.
• Patient-derived ES cultures (PDES) were established and characterized to improve preclinical modeling.
• Understanding ES biology requires models that reflect tumor heterogeneity.

Purpose of the Study:

• To establish and characterize patient-derived Ewing sarcoma (PDES) cultures in vitro.
• To assess the utility of PDES in predicting clinical drug responses.
• To compare PDES with traditional cell lines for preclinical drug screening.

Main Methods:

• Fluorescence in situ hybridization, RT-PCR, and western blotting for EWSR1 fusion analysis.
• Immunofluorescence and immunohistochemistry for proliferation and target gene expression.
• Next-generation sequencing for DNA and transcriptomic profiling.
• Drug sensitivity assays with chemotherapeutics, radiation, and targeted agents.

Main Results:

• PDES confirmed EWSR1 fusion DNA, RNA, and protein expression.
• PDES gene expression and proliferation markers correlated with patient tumors.
• PDES exhibited slower growth, radioresistance, and chemotherapy resistance compared to cell lines.
• PDES showed sensitivity to multi-targeted tyrosine kinase inhibitors (mTKIs) and trabectedin, mirroring clinical responses.

Conclusions:

• PDES models accurately reflect Ewing sarcoma biology and patient tumor characteristics.
• PDES demonstrate differential drug responses, including resistance and sensitivity, relevant to clinical outcomes.
• Incorporating PDES into preclinical pipelines can enhance the prioritization of targeted agents for Ewing sarcoma.