| Objective To investigate the effect of miR-381 on proliferation, invasion and migration of papillary thyroid carcinoma cell IHH-4 via targeting high-mobility group box 1 protein (HMGB1). Methods Purchasing one of thyroid papilloma IHH-4 cells and normal thyroid Nthy-ori-3 cells, taking the third generation of cells and cultured 48 h, the mRNA level of miR-381 and HMGB1 in normal thyrocyte Nthy-ori-3, IHH-4 cell were determined by qRT-PCR; miR-381 and HMGB1 expression levels in IHH-4 cells were detected after transfection with Lipofectamine 2000. The targeted-relationship between miR-381 and HMGB1 was predicted by bioinformatics and conformed by luciferase reporter assay. After inoculating with 2×105/mL cell density per well, IHH-4 cells were randomly divided into IHH-4 group (IHH-4 group of thyroid papilloma cells), miR-381 mimic group (miR-381 mimic transfection group), pc-HMGB1 group (HMGB1 overexpression transfection group), mimic+pc-HMGB1 group (miR-381 mimic and pc-HMGB1 co-transfection group), each group was established three wells. IHH-4 cell proliferation was determined by CCK8 assay, cell invasion and migration were determined by Transwell and wound healing assay respectively; expression level of Ki67, metalloproteinase-2 (MMP-2), MMP-9 and receptor for advanced glycation endproducts (RAGE) were determined by western blot. Results Compared with Nthy-ori-3 cells, the mRNA level of miR-381 in IHH-4 cells was decreased (P<0.01), but HMGB1 was increased (P<0.01). Compared with the IHH-4 group, the expression of miR-381 in the miR-381 mimic group was increased (P<0.01). There is a targeting relationship between miR-381 and HMGB1. Compared with the IHH-4 group, the proliferation folds, Ki67 expression, the number of invasive cells, scratch closure rate, the expressions of MMP-2, MMP-9 and RAGE in the miR-381 mimic group were all decreased (all P<0.01), while those in the pc-HMGB1 group were all increased significantly (all P<0.01). In addition, compared with miR-381 mimic group, the proliferation folds, Ki67 expression, the number of invasive cells, scratch closure rate, the expressions of MMP-2, MMP-9 and RAGE in mimic+pc-HMGB1 group were all increased significantly (all P<0.01). Conclusion MiR-381 inhibits cell proliferation, invasion and migration of IHH-4 cells by targeting down-regulation of HMGB1 experssion. |
