BSCI-01. Small RNAseq analysis of microRNAs in brain metastasis

Abstract MicroRNAs (miRNAs) are a well-known subclass of short non-coding RNAs responsible for posttranscriptional gene silencing and have been described as dysregulated in many cancers. They have also been shown to be both specific diagnostic, prognostic, and predictive biomarkers as well as therapeutic targets. Therefore, specific miRNA expression patterns of BMs of various origins could serve as a promising diagnostic tool for determining both the original tumor and the prognosis in patients with BMs of unknown origin.For identifying significantly dysregulated miRNAs among BMs (n = 90) with various origin and non-tumor brain tissues (n = 12), small RNAseq analyses were used. cDNA libraries were prepared using QIAseq miRNA Library Kit and purified by Qiaseq beads. The final sequencing analyses were performed by Next 500/550 High Output v2 Kit-75 cycles using the NextSeq 500 instrument. For miRNA mapping and analysis, Miraligner and MirBase were used.Bioinformatic analysis of obtained sequencing data identified 472 significantly dysregulated miRNAs (logFc>2, adj.p-value