Effects of microRNA-21 on the biological functions of T-cell acute lymphoblastic lymphoma/leukemia.

Previous studies have demonstrated that microRNA-21 (miR-21) is an oncogene and is significantly upregulated in tumor tissue. However, its association with T-cell acute lymphoblastic lymphoma/leukemia (T-ALL) remains poorly understood. The aim of the present study was to investigate the effects of miR-21 on T-ALL cells by constructing Jurkat cells infected with recombinant adenovirus adv-miR-21 or adv-anti-miR-21. In addition, the target gene of miR-21 was identified by reverse transcription-quantitative polymerase chain reaction and western blotting. The results demonstrated that miR-21 expression in Jurkat cells was markedly upregulated. Furthermore, upregulating miR-21 expression in Jurkat cells promoted cell proliferation and invasion and decreased the apoptosis rate. By contrast, knockdown of miR-21 in Jurkat cells suppressed proliferation and invasion and increased the apoptosis rate. Furthermore, the results indicated that signal transducer and activator of transcription (STAT) 3 was targeted by miR-21, and that miR-21 inhibited STAT3 expression at the protein level rather than at the messenger RNA level. In conclusion, targeting the inhibition of miR-21 may be a novel therapeutic strategy for patients with T-ALL.