FFPE-samples from cavitational ultrasonic surgical aspirates are suitable for RNA profiling of gliomas

During surgical procedures of gliomas, tissular material obtained from cavitational ultrasonic surgical aspirators (CUSAs) is generally discarded but can exceed amount and quality of certain tumour core resections (TCRs). From archived FFPE-samples, we compared the profiles of somatic mutations and gene expression in the solid material from aspirates and TCRs obtained from the same patients in selected gliomas encompassing grade II to IV. Despite the characteristic heterogeneity of gliomas, we found substantial similarities between the corresponding aspirates and TCRs that included mutations used in the clinical routine and glioma-associated transcriptional signatures. Based on these results, we confirmed the suitability of CUSA-fixed biomaterial from glioma surgeries for downstream applications. Two types of comparisons: (i) between grade IV and grade II/III samples, independently of the origin of the tissue (TCR, aspirate) (n = 4 for each condition), and (ii) between TCR and CUSA-derived material, independently of the diagnosis and degree (n = 4 for each condition).