Spatial Proteomic Profiling, a Novel Method for Detecting Diagnostic and Prognostic Proteins in Pediatric Sarcoma

Area of Science:

• Oncology
• Proteomics
• Biomarker Discovery

Background:

• Pediatric sarcomas are rare childhood cancers with distinct genetic profiles.
• Understanding protein expression is crucial for diagnosis, prognosis, and treatment.
• Digital spatial profiling (DSP) offers a novel approach to study protein alterations.

Purpose of the Study:

• To identify protein expression profiles in pediatric sarcomas using DSP.
• To correlate protein expression with clinical outcomes.
• To discover potential diagnostic and therapeutic biomarkers.

Main Methods:

• Proteomic DSP was performed on formalin-fixed, paraffin-embedded tissue sections from pediatric sarcoma cases (Ewing sarcoma, Osteosarcoma, Alveolar rhabdomyosarcoma, Embryonal rhabdomyosarcoma).
• The GeoMx NanoString platform was used to analyze the expression of 580 proteins.
• Immunohistochemistry was employed for validation of specific protein markers.

Main Results:

• Broad expression of proteins involved in epigenetic regulation, signaling, and mesenchymal differentiation was observed across tumor types.
• Tumor-specific protein profiles were identified.
• Differential expression of Cyclin D1 in Ewing sarcoma, S100A4 in Osteosarcoma, and IKKi/IKKe in rhabdomyosarcomas was noted.
• Immunohistochemical validation confirmed elevated Cyclin D1 in Ewing sarcoma and S100 in Osteosarcoma.

Conclusions:

• DSP is a valuable high-resolution tool for identifying clinically relevant protein biomarkers in pediatric sarcomas.
• The identified protein profiles and differentially expressed proteins provide a foundation for further research into diagnostic, prognostic, and therapeutic applications.
• This study highlights potential new avenues for targeted therapies in childhood sarcomas.