MicroRNA-155 is a potential molecular marker of natural killer/T-cell lymphoma

Natural killer/T-cell lymphoma (NKTCL) is characterized by its highly aggressive nature and rapid progression. MicroRNAs (miRNAs) play key roles in the development of NKTCL. We utilized next-generation Solexa high-throughput sequencing to compare miRNA expression in the SNK-6 and YTS NKTCL cell lines with expression in normal NK cells. We found that 195 miRNAs were upregulated in the SNK-6 cells and 286 miRNAs were upregulated in the YTS cells. Based on those results, we selected six miRNAs, including miRNA-155, and confirmed their expression using real-time polymerase chain reaction. Expression of miRNA-155 was higher in SNK-6 and YKS cells than in normal NK cells. We next determined the levels of miRNA-155 in the serum of healthy individuals and NKTCL patients, and correlated its expression with clinical parameters and inflammatory factors detected using enzyme-linked immunoabsorbent assays. Levels of miRNA-155 were higher in NKTCL patients' serum than in serum from healthy individuals. miRNA-155 expression was higher in patients with stable or progressive disease (SD+PD) than in those with partial or complete remission (PR+CR). While further studies are needed to clarify the underlying molecular mechanisms, it appears miRNA-155 may be a molecular marker of NKTCL.