RESUMO
MicroRNA-21 (miR-21) is considered to play a key role in many cellular processes, affecting tumorigenesis by inhibiting target gene expression. However, its role in diffuse large B-cell lymphoma (DLBCL) is still unclear, and there are no in depth studies on relationship between miR-21 and cellular phenotype. This study was aimed to investigated the expression and role of miR-21 in the regulation of cell biological behavior in DLBCL. The expressions of miR-21 in three DLBCL cell lines were detected by real-time quantitative reverse-transcription polymerase chain reaction (qRT-PCR). The possible roles of miR-21 in the biological and behavioral properties of DLBCL were explored by transfection of anti-miR-21 for miR-21 knockdown. In addition, PDCD4 and PTEN were assessed by luciferase reporter assay, qRT-PCR and Western blot. The results revealed that miR-21 expression was significantly upregulated in activated B-cell-like DLBCL cells as compared to germinal centre-like DLBCL cells. The inhibition of miR-21 could induce suppression of proliferation and invasion, as well as increase apoptosis in DLBCL. Moreover, knockdown of miR-21 increased the expressions of PDCD4 and PTEN at the protein level but not at the mRNA level. It is concluded the miR-21 can regulate proliferation, invasion, and apoptosis, so it has a potential therapeutic application in DLBCL.