RESUMEN
OBJECTIVE@#To investigate the expression of miR-155 in patients with diffuse large B-cell lymphoma (DLBCL), and to explore the effect of transfection of miR-155 inhibitor on the biological characteristics of DLBCL cells.@*METHODS@#A total of 76 patients with DLBCL treated in our hospital were selected from April 2013 to December 2017. In the same time, 40 cases of lymph node reactive hyperplasia (LNRH) were selected as control group. DB cells were cultured and divided into miR-155 inhibitor, negative control and blank groups. The expressions of miR-155 in DLBCL, negative and blank control groups were detected by using real-time PCR, the cell proliferation was detected by MTT assay, the apoptosis was detected by flow cytometry, and the cell migration and invasion were detected by Transwell assay.@*RESULTS@#The relative expression level of miR-155 in tissues of DLBCL patients was significantly higher than that in tissne of controls (1.93±0.16 vs 1.01±0.09) (t=33.991, P=0.000). The expression level of miR-155 increased (P＜0.05) in DLBCL patients with LDH level abnormarity, BCL-2, MUM1, Ki-67≥50%, non-GC type, Ann Arbor stage III-IV, extranodal lesion number≥2 and IPI score 3-5. The relative expression level of miR-155 in the miR-155 inhibitor group was lower than that in the negative control group and the blank group (P＜0.05). The absorbance (A) values at 24, 48, 72 and 96 h of culture in the miR-155 inhibitor group were lower than those in the negative control group and the blank group (P＜0.05), while the apoptotic rate was higher than that in the negative control group and the blank group (P＜0.05). Both the migrating cells and invading cell number in the miR-155 inhibitor group were lower than those in the negative control group and the blank group (P＜0.05).@*CONCLUSION@#The miR-155 highly expresses in DLBCL tissue, which relates with tumor malignancy and invasion progression. The specific inhibition of miR-155 expression in DB cells can reduce cell proliferation, accelerate cell apoptosis, and inhibit cell migration and invasion.