PATH-02. ANALYSIS OF MICRORNA EXPRESSION IN BRAIN METASTASES USING NEXT-GENERATION SEQUENCING

Abstract BACKGROUND Brain metastases (BMs) are intracranial tumors that frequently occur in adult cancer patients. Because the prognosis of patients with BM individually varies, it would be useful to improve prognostic scoring tools by including new high-performance biomarkers. MicroRNAs (miRNAs) appear promising this regard as they highly stable and, thus, suitable for both next-generation sequencing (RNA-Seq) and retrospective analyses formalin-fixed paraffin-embedded (FFPE) tissues.Material METHODS Total RNA enriched miRNAs was isolated from 71 freshly frozen histopathologically confirmed BMs origin 5 tumor types (ca lung - 37%, melanoma 23%, ca breast 18%, RCC 15%, CRC 7%) using mirVana miRNA Isolation Kit (Thermo Fisher Scientific). Sequencing libraries were prepared QIAseq Library (Qiagen) sequenced NextSeq 500 platform (Illumina). The molecules subsequently transcribed total samples a set 119 FFPE tissues TaqMan Advanced cDNA Synthesis Kit, expression selected validated pilot experiment qPCR Fast Master Mix appropriate MicroRNA Assays (all Thermo RESULTS differential analysis identified 373 significantly different among groups (p< 0.001). A molecular classifier based on 32 able classify all correctly. Out these, seven, miR-122-5p, miR-141-3p, miR-146a-5p, miR-194-5p, miR-200c-3p, miR-211-3p, miR-215-5p, chosen subsequent validation their validated. CONCLUSIONS Presented results confirm importance studying dysregulated diagnostic potential miRNAs. study grant support Ministry Health Czech Republic No. NV18-03-00398.