This dataset is about the differentially expressed exosomal microRNA between MCPyV-negative and -positive MCC cell lines.

Abstract: MicroRNAs (miRNAs) are small non-coding RNAs responsible for post-transcriptional regulation of gene expression through interaction with messenger RNAs (mRNAs). In the past few years, evidence of the presence of cellular miRNAs in extracellular human body fluids such as serum, plasma, saliva, and urine has accumulated. Also, miRNAs have found in membrane-bound vesicles such as exosomes. They are involved in critical biological processes and dysregulated in a variety of diseases, including cancer and infections. Although little known about the role of exosomal miRNAs, it has demonstrated that miRNAs secreted by virus-infected cells transferred to and act in uninfected recipient cells, thereby contributing to spreading the pathogenic properties of the virus. Merkel cell carcinoma (MCC) is skin cancer of neuroendocrine origin. The significant risk factors are ultraviolet light exposure and the presence of integrated Merkel cell polyomavirus (MCPyV) genome. In this work, we sequenced exosomal miRNAs of MCPyV-negative (MCC13 and MCC26) and –positive MCC (MKL1 and MKL2) cell lines. In total, 519 exosomal miRNA were identified as a differentially expressed between the virus-negative and virus-positive cell lines and selected eight exosomal miRNA validated on exosomal serum/plasma healthy donors and MCC patients by qRT-PCR. miR-222-3p target genes predicted using the ExoCarta, TargetScan, and miRTarBase databases to understand the exosomal miR-222-3p influence in health and disease. The result showed the miR-222-3p is present in exosomes from Merkel cell carcinoma cell culture, serum of healthy donors and plasma of MCC patients. The sequencing result indicated that miR-222-3p is more abundant in exosomes generated by virus-negative MCC cells than in exosomes secreted by virus-positive MCC cell lines. qRT-PCR validation confirmed this finding — however, the miR-222-3p presence at a higher level in exosomes in healthy condition than in pathophysiological state. The enrichment analysis showed 11 of predicted 20 common miR-222-3p targets expressed in leukocytes and 6 of them identified as differentially expressed proteins in MCC cell lines. The role of miR-222-3p as the messenger in the cell-to-cell communication in the cancer environment and circulation discussed.