Research Paper Volume 12, Issue 1 pp 340—358

Downregulation of ABI2 expression by EBV-miR-BART13-3p induces epithelial-mesenchymal transition of nasopharyngeal carcinoma cells through upregulation of c-JUN/SLUG signaling

Figure 3. EBV-miRNA-BART13-3p directly targets the cell migration inhibitor ABI2. (A) Venn diagram of the number of target genes of BART13-3p predicted with three different databases—Reptar, miRanda and VIRmiRNA. Nine genes were predicted by all three databases, ABI2, TBC1D2B, ZNFX1, CSNK1G1, C9orf72, SLC41A1, NUFIP2, EIF5 and CCNE2. (B) Heat map obtained from mRNA microarray analysis (CNE1-BART13-3p versus CNE1-NC). CNE1 cells were transfected with BART13-3p mimics or NC for 24 h, and mRNA was isolated and then evaluated using microarray analysis. (C) Bioinformatics predictions showed the possible binding site of ABI2 3′-UTR region complementary with BART13-3p. Mutant sequences were showed as well. (D) Luciferase reporter assay. HEK293T cells were co-transfected with EBV-miR-BART13-3p NC or mimics and luciferase reporters carrying the predicted paired target site of ABI2 3′UTR (WT) or mutant (Mut). (EG) RT-qPCR, western blot and immunofluorescence all indicated overexpression of BART13-3p contributes to decrease of ABI2 expression in NPC cells. (H) Immunohistochemistry on tumor slices of mouse models confirmed overexpression of BART13-3p reduced ABI2 expression in NPC tissues. (I) ABI2 protein expression in paraffin-embedded NPC specimens was detected by immunohistochemical staining. The staining intensity was divided into four grades, score ranging from 0 to 12. Scale bar, 20μm (G) and 100μm (H, I). Error bars represent SEM. (*P<0.05; **P<0.01; ***P<0.001).