Objective To investigate the effect of long non-coding RNA(LncRNA)plasmacytoma variant translocation gene 1(PVT1)on the biological behavior of diffuse large B-cell lymphoma(DLBCL)cells and its potential mechanism.Methods Tis-sue specimens were collected from 41 patients with DLBCL and 15 patients with lymph node reactive hyperplasia(RLH),and nor-mal human B lymphocytes GM12878 and human DLBCL cells(OCI-Ly3,U2932,TMD8)were cultured in vitro.TMD8 cells were transfected and divided into control group(transfected with Lipofectamine-2000 alone),si-NC group(transfected with si-NC),in-hibitor-NC group(transfected with inhibitor-NC),si-PVT1 group(transfected with si-PVT1),miR-145-5p inhibitor group(trans-fected with miR-145-5p inhibitor),and si-PVT1+miR-145-5p inhibitor group(transfected with si-PVT1 and miR-145-5p inhibi-tor).The qRT-PCR method was used to measure the mRNA expression levels of PVT1 and miR-145-5p in each group of cells;Western Blot was used to measure the protein expression level of cyclin-dependent kinase 6(CDK6);CCK-8 assay was used to measure the proliferation of TMD8 cells;flow cytometry was used to measure the change in cell cycle of TMD8 cells;Transwell assay was used to measure the migration and invasion abilities of TMD8 cells;RNA pull-down and dual-luciferase reporter assay were used to verify the targeting relationship between PVT1,miR-145-5p,and CDK6.Results The mRNA expression level of PVT1 and the protein expression level of CDK6 in DLBCL tissue were significantly higher than those in RLH tissue,and the expression level of miR-145-5p in DLBCL tissue was significantly lower than that in RLH tissue(t=14.264-24.445,P＜0.05).Compared with GM12878 cells,OCI-Ly3,U2932,and TMD8 cells had signifi-cant increases in the mRNA expression level of PVT1 and the protein expression level of CDK6 and a significant reduction in the expression level of miR-145-5p(F=69.557-234.718,P＜0.05).There were significant differences between the six groups of cells in PVT1,miR-145-5p,CDK6,proliferation rate,the proportion of cells in G0/G1 phase,the proportion of cells in S phase,and the number of cells with migration and invasion(F=25.589-319.150,P＜0.05).Compared with the control group,the si-PVT1 group had significant reductions in PVT1,CDK6,proliferation rate,the proportion of cells in S phase,and the number of cells with migration and invasion,as well as significant increases in the expression of miR-145-5p and the proportion of cells in G0/G1 phase(P＜0.05),while the miR-145-5p inhibitor group showed opposite changes(P＜0.05).Down regulating the expression of miR-145-5p could weaken the inhibitory effect of PVT1 knockdown on the malignant biological behavior of TMD8 cells(P＜0.05).Overexpression of PVT1 increased the protein expression level of CDK6,proliferation rate,the proportion of cells in S phase,and the number of cells with migration and invasion and reduced the expression of miR-145-5p and the proportion of cells in G0/G1 phase(F=38.025-327.887,P＜0.05).This study showed that miR-145-5p was a target gene of PVT1,and miR-145-5p could down regulate the expression of CDK6.Conclusion PVT1 knockdown can inhibit the malignant biological behavior of DLBCL cells,possibly by regulating the miR-145-5p/CDK6 axis.
维普
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