RNY4 in circulating exosomes of patients with pediatric Anaplastic Large Cell Lymphoma: an active player?

Emerging evidence indicates that extracellular vesicles, particularly exosomes, play a role in several biological processes and actively contribute to cancer development and progression, by carrying and delivering proteins, transcripts and small RNAs (sRNAs). We profiled by RNA-seq the sRNA content of circulating exosomes of 20 pediatric patients with Anaplastic Large Cell Lymphoma (ALCL), 5 healthy controls and of 5 ALCL cell lines. Our analysis disclosed that non-miRNA derived sRNAs constitute the prominent fraction of sRNA loaded in exosomes. A fragment of RNY4 was the most abundant of 180 sRNAs significantly enriched in exosomes of ALCL patients compared to controls. Further investigation by qRT-PCR of RNY4 fragments and full-length sequence disclosed that the latter is massively loaded into exosomes of ALCL patients with more advanced and aggressive disease. Since recent findings supported a role of RNY4 in the modulation of tumor microenvironment, our data open new possibilities to understand how tumor derived exosomes can facilitate disease spread in ALCL patients. Tumor biopsies and plasmatic exosomes from ALCL pediatric patients; plasmatic exosomes from healthy donors; exosomes from ALCL cell lines culture surnatants.