Abstract 347: Neogenin as an anti-invasive target for diffuse intrinsic pontine gliomas

Abstract

Abstract Introduction. Diffuse Intrinsic Pontine Glioma (DIPG) is a rare high-grade tumor of the brainstem that occurs almost exclusively in children. The significant mortality rates of DIPG stem largely from its capacity to invade adjacent normal brain. We have previously published studies identifying the axon guidance factor netrin-1 and its receptor neogenin as key drivers regulating brain tumor invasion in medulloblastoma and glioblastoma. Here we expand this work to investigate the role of netrin-1 and neogenin in DIPG and identify them as putative biomarkers and governors of tumor invasion. Methods. Urine of 49 DIPG patients and 42 age- and sex-matched controls was collected. Netrin-1 expression was quantified by ELISA. Results were subjected to univariate and multivariate statistical analyses and compared between clinical cohorts. In vitro experiments with established DIPG cell lines utilized RTqPCR, Western blot and flow cytometry to quantify expression of netrin-1 and neogenin. The effect of neogenin blockade on viability and invasion was assessed by flow cytometry (n=3) and transwell chamber assays (n=3) respectively. Results. Patient samples revealed a significantly low level of urinary netrin-1 compared to matched controls (p<0.005). This result was corroborated with cell lines in vitro. Interestingly, its receptor neogenin was upregulated in these cells when compared to control glial cells when quantified by mRNA, protein and FACS analysis. Blockade of neogenin in DIPG cell lines resulted in an increase of cell death and a significant decrease of cell invasion. Conclusion. Expanding on previous work, this data suggests that urinary levels of netrin-1 may have utility as a non-invasive biomarker for DIPG. Our data demonstrates the vital role of neogenin as a regulator of tumor invasion and survival in DIPG. The blockade of neogenin in DIPG cells also demonstrates the potential utility of neogenin as a cell-surface druggable target, capable of reducing tumor invasion and increasing tumor cell death. Citation Format: Julie Sesen, Jessica Driscoll, Edward Smith. Neogenin as an anti-invasive target for diffuse intrinsic pontine gliomas [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 347.