Functional genomics identifies AMPD2 as a new prognostic marker for undifferentiated pleomorphic sarcoma

Area of Science:

• Oncology
• Genetics
• Biomarker Discovery

Background:

• Soft-tissue sarcomas, including undifferentiated pleomorphic sarcoma (UPS), are rare and aggressive cancers with limited prognostic biomarkers.
• Small sample sizes in individual studies hinder biomarker identification for rare cancers.
• Publicly available 'omics' data offers a powerful resource for overcoming these limitations.

Purpose of the Study:

• To identify a robust prognostic biomarker for predicting patient outcomes in undifferentiated pleomorphic sarcoma (UPS).
• To validate the identified biomarker using multiple experimental approaches.
• To explore the functional role of the biomarker in UPS tumorigenesis.

Main Methods:

• Integrated analysis of transcriptome data from two independent UPS cohorts.
• Survival association testing to identify genes correlated with patient outcomes.
• Immunohistochemistry validation on a tissue microarray.
• DNA copy-number analysis and gene set enrichment analysis.
• Functional studies involving AMPD2 knockdown in an UPS cell line.

Main Results:

• High expression of adenosine monophosphate deaminase 2 (AMPD2) was identified as a significant predictor of worse outcomes in UPS across both cohorts.
• High AMPD2 expression correlated with genetic gains at the AMPD2 locus.
• AMPD2-high UPS tumors showed enrichment in pro-tumorigenic molecular signatures.
• In vitro and in vivo experiments demonstrated that AMPD2 knockdown inhibits UPS cell proliferation and tumorigenicity.

Conclusions:

• Adenosine monophosphate deaminase 2 (AMPD2) serves as a robust prognostic biomarker for predicting poor outcomes in undifferentiated pleomorphic sarcoma (UPS).
• The study demonstrates a successful strategy for rare cancer biomarker discovery by integrating multi-omics data and functional validation.
• This approach can be a blueprint for identifying biomarkers in other rare malignancies.