Ror1 mrna expression in glioma - a novel prognostic biomarker

Abstract BACKGROUND Glioblastoma is the most common and aggressive primary brain tumor in adults. Despite maximal surgical resection followed by concomitant chemo-/radiotherapy, the three-year survival remains less than 5%. Receptor tyrosine kinase-like orphan receptor 1 (ROR1) overexpression is associated with poor prognosis in several cancers. ROR1 therapeutics are in Phase I/II clinical trials making it an exciting novel target with translational potential to explore for glioblastoma treatment. The aim of this study was to examine the association between ROR1 mRNA expression and overall survival, by applying the WHO 2021 classification to transcriptomic glioma datasets. METHODS Clinical, histological, and molecular data was extracted from The Cancer Genome Atlas (TCGA), Chinese Glioma Genome Atlas (CGGA), Repository for Molecular Brain Neoplasia (REMBRANDT), and GSE16011 (GRAVENDEEL) projects via the GlioVis portal. Using the WHO 2021 classification, the dataset was appropriately re-classified. Only confirmed cases of astrocytoma, oligodendroglioma, or glioblastoma, and ROR1 mRNA expression data were included in the analysis, which included a total of 2,303 cases. 981 cases comprised the low-grade glioma cohort and 1322 cases were included in the high-grade glioma cohort. ROR1 mRNA expression from the four datasets was normalized within each dataset, combined, and divided into high and low expression groups. ROR1 expression and survival correlations were estimated with Kaplan-Meier survival analysis and Mantel-Cox test using GraphPad Prism v9. RESULTS Those with high ROR1 expression had an overall median survival of 4.5 months, as compared to 21.4 months in the low ROR1 expression cohort (p< 0.0001). High-grade gliomas had the highest ROR1 mRNA expression across the consortium when compared to the low-grade glioma cohort (p< 0.0001). CONCLUSION The results of this study indicate an association between overall survival in glioma and ROR1 expression. In addition, targeting ROR1 could hold translational importance for novel putative treatment in glioblastoma patients.