BIOM-33. URINARY D-ASPARAGINE AS A NOVEL BIOMARKER FOR DETECTION OF GLIOBLASTOMA

Abstract Despite extensive research efforts, clinically applicable liquid biomarkers for glioblastoma (GBM) have yet to be established. This study aimed to identify novel blood and urinary biomarkers for GBM, with a particular focus on chiral amino acids. A total of 33 patients with glioma (WHO grade 2: n=10, grade 3: n=6, grade 4: n=17) and 24 healthy volunteers were enrolled. Chiral amino acid analysis was conducted on resected tissue samples (both tumor and non-tumor), as well as corresponding blood and urine samples, to quantify L- and D-isomers of amino acids. To validate these findings, we also evaluated chiral amino acid profiles in a GBM mouse model. Among the findings, D-asparagine (D-Asn) and several L-amino acids were present at significantly higher concentrations in tumor tissues than in non-tumor brain tissues. Notably, both blood and urinary D-Asn levels were significantly lower in GBM patients compared to healthy individuals (p<0.05 and p<0.001, respectively). Furthermore, urinary D-Asn levels increased significantly after initial GBM treatment (p<0.05), suggesting its potential utility in disease monitoring. Urinary D-Asn also showed excellent diagnostic performance in distinguishing GBM patients from healthy controls, with an area under the curve (AUC) of 0.93, sensitivity of 0.88, and specificity of 0.92. Similar trends in amino acid profiles were observed in the GBM mouse model, supporting translational relevance. In conclusion, urinary D-Asn appears to be a promising, non-invasive biomarker for the detection and monitoring of GBM, with potential for clinical application.