ALBERT

Description: Background: Erdheim-Chester disease (ECD) is a rare hematological malignancy, belonging to the L-group histiocytoses. ECD is characterized by multi-systemic proliferations of mature histiocytes in a background of inflammatory stroma. The inflammatory and neoplastic characteristics of the disease comprise a complex medical challenge for its diagnosis and treatment. MicroRNAs (miRNAs/miRs) are short non-coding RNAs (~22 nucleotides) that regulate gene expression in a sequence specific manner and play an important role in cancer development and progression. Since miRNAs are released into the blood by tumor cells, they may be used as biomarkers to distinguish between cancer patients and healthy individuals and to assist in determining treatment response. Moreover, miRNA-mRNA interactions can determine the molecular mechanism by which miRNAs and their target genes are involved in ECD and may suggest novel therapeutic options for these patients. To date, this is the first study elucidating the role of miRNA in ECD. Aims: The main focus of this study is to identify miRNAs that are differentially expressed in ECD patients compared to healthy controls and any clinical utility they have as potential biomarkers in ECD diagnosis, as well as to investigate their role in ECD pathogenesis, which may lead to new therapeutic options. Preliminary results: Using the nCounter Human miRNA Expression Assay (NanoString Technologies), we analyzed the plasma miRNA expression profiles of 6 ECD patients (BRAF V600E) compared to 6 healthy individuals. Of the 800 mature miRNAs analyzed, 234 miRNAs showed different expression levels in these samples. Principal component analysis (PCA) was applied to experimental quality control. The miRNAs from healthy donors were clustered separately from the ECD samples indicating a distinct miRNA expression pattern between these groups (Fig. 1A, 1B). Among the 131 miRNAs remaining in the final analysis (FDR