Metabolomic profiling and stable isotope tracing of human schwannomas: A novel perspective on tumor biology and radiation response.

Background: Although schwannomas are common and benign, their growth patterns are often hard to predict. Currently, surgery and radiotherapy are the only standard treatments. Since metabolites are the end products of genes and proteins, metabolomics may reveal downstream tumor features in ways that other -omics cannot. Here, we use metabolomic profiling and stable isotope tracing to characterize primary human schwannomas and describe their changes following radiation in patient-derived xenografts. Methods: Schwannomas collected during surgical resection underwent metabolomic profiling with gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry ( Results: The schwannoma metabolome differs from that of Schwann cells, and metabolomics-based clustering of schwannomas resembles DNA methylation-based classification. In xenografts, radiation decreases cellular proliferation and produces small but detectable changes to the tricarboxylic acid (TCA) cycle and nucleotide metabolism. Conclusions: Schwannomas have distinct metabolic signatures compared to the Schwann cells from which they originate. Schwannoma xenograft metabolism is surprisingly robust to radiotherapy, and xenografts readily incorporate glutamine into the TCA cycle, urea cycle, and pyrimidine synthesis.