RESUMEN
<p><b>OBJECTIVE</b>To study the expression of microRNAs (miRNAs) in extranodal NK/T cell lymphoma, nasal type (EN-NK/T-NT).</p><p><b>METHODS</b>TaqMan low density arrays were used to assess the expression level of 665 miRNAs in one case of EN-NK/T-NT and one normal nasopharyngeal tissue. Ninety-five miRNAs were found to be aberrantly expressed (86 being up-regulated and 9 being down-regulated) in EN-NK/T-NT, compared with normal nasopharyngeal tissue. The aberrant expression was found to be most significant in 8 miRNAs. According to the literature and miRNA database, the expression patterns of these 8 miRNAs were further analyzed in 15 cases of EN-NK/T-NT and 3 normal nasopharyngeal specimens, using the single tube TaqMan microRNA assays.</p><p><b>RESULTS</b>Three of the 8 miRNAs showed statistically significant difference in the expression in EN-NK/T-NT and normal nasopharyngeal specimens. These 3 miRNAs (miR-223, 886-3p and 34c-5p) were considered to play crucial roles in hemopoiesis, cellular proliferation and apoptosis. MiR-223 and miR-886-3p were significantly over-expressed in EN-NK/T-NT (P = 0.002, P = 0.010) while miR-34c-5p was significantly under-expressed (P = 0.017).</p><p><b>CONCLUSIONS</b>Certain types of miRNAs, especially those related to hemopoiesis, cellular proliferation and apoptosis, are aberrantly expressed in EN-NK/T-NT. The potential role of miRNAs in the molecular genetics of EN-NK/T-NT requires further investigation.</p>