Introduction: Glioblastoma (GBM) is the most common primary adult brain tumour with a median overall survival (OS) of 12-15 months. Molecular characterization of multiple immuno-oncology targets in GBM may help target novel immunotherapeutic strategies. We used NanoString GeoMx® Digital Spatial Profiling (DSP) to assess multiple immuno-oncology protein targets in methylated versus unmethylated Glioblastoma IDH-wildtype. Methods: NanoString GeoMx® DSP technology uses multiple primary antibodies conjugated to indexing DNA oligos with a UV photocleavable linker. Tissue regions of interest (ROI) are selected with bound fluorescent antibodies, oligos are released via a UV-mediated linker and quantitated. We used DSP multiplex analysis of 31 immuno-oncology proteins and controls (CD4, CD14, CD68, CD8A, B7.H3, PD.L1, CD19, FoxP3, CD44, STAT3.phospho.Y705, CD45, Pan.Cytokeratin, MS4A1.CD20, CD45RO, PD1, CD3, Beta.2.Microglobulin, VISTA, Bcl.2, GZMB, PTEN, Beta.Catenin, CD56, Ki.67, STAT3, AKT, P.AKT, S6, Histone H3, IgG Rabbit Control, Mouse IgG Control) from ROIs in a cohort of 10 Glioblastomas IDH-wildtype (5 methylated, 5 unmethylated). An nCounter platform allowed quantitative comparisons of antibodies between ROIs in MGMT methylated and unmethylated tumours. Mean protein expression counts between methylated and unmethylated GBM were compared using technical and biological replicates. Results: The analysis showed 10/27 immuno-oncology target proteins were significantly increased in methylated versus unmethylated Glioblastoma IDH-wildtype tumour core (false discovery rate FDR <0.1 by Benjamini-Hochberg Procedure). Conclusions: NanoString GeoMx® DSP was used to analyse multiple immuno-oncology protein target expression in methylated versus unmethylated glioblastoma IDH-wildtype. In this small study there was a statistical increase in CD4, CD14, CD68, CD8A, B7-H3, PDL-1, CD19, FoxP3, CD44 and STAT3 protein expression in methylated versus unmethylated GBM tumour core, however this requires larger cohort validation. Advanced multiplex immuno-oncological biomarker analysis may be useful in identifying biomarkers for novel immunotherapeutic agents in GBMs.
|Journal||Journal of Oncology|
|Publication status||Accepted/In press - 2 Feb 2021|