Effects of miR-217 Regulation of TIMP3 expression on Biological Behavior of Laryngeal Carcinoma Cells

SONG Jian-tao; ZHAO Hai-jun; ZHENG Jian-jun; WANG Xiang-feng

doi:10.3969/j.issn.1002-3429.2019.03.015

Abstract：Objective To investigate the effect of miR-217 regulation of metallopeptidase inhibitor 3 (TIMP3) expression by on biological behavior of laryngeal carcinoma (LC) cells. Methods A total of 32 patients with LC who underwent partial or total laryngectomy were enrolled. Cancerous tissues and adjacent normal tissues 2 cm away from the tumor were collected from each patient. Human LC cell line Hep2 was selected, and miR-217 mimics and Control mimics were transfected into cells as miR-217 mimics group and miR-217 NC group, respectively, and TIMP3 3'-UTR wild type (Wt) plasmid and The TIMP3 3'-UTR mutant (Mut) plasmid was transfected into cells, respectively.Real-time Quantitative PCR (RT-qPCR) was used to detect the expression levels of miR-217 and TIMP3 in LC tissues. Dual luciferase reporter gene assay was used to verify the regulation of miR-217 and TIMP3 in LC cell line Hep2. The cell proliferation was detected by MTT proliferation assay, and the cell migration and invasion were detected by Transwell assay. In addition, the correlation between miR-217 expression in LC and its clinical features was analyzed. Results The results of qPCR assay showed that the expressions of miR-217 in adjacent normal tissues and LC tissues were 1.53±0.21 and 0.68±0.13, respectively, and the expression levels of TIMP3 were 1.18±0.15 and 0.31±0.08, respectively, suggesting significant differences (P＜0.05). The dual luciferase assay showed that luciferase activities in miR-217 mimics+TIMP3 3'-UTR Wt group, miR-217 NC+TIMP3 3'-UTR Wt group, miR-217 mimics+TIMP3 3'-UTR Mut group, and miR-217 NC+TIMP3 3'-UTR Mut group were 1.79±0.31, 1.15±0.11, 1.28±0.28 and 1.18±0.19, respectively. The difference was statistically significant (t=12.09, P=0.019). The difference in the activity of the dual luciferase between the miR-217 mimics+TIMP3 3'-UTR Wt group and the miR-217 NC+TIMP3 3'-UTR Wt group was statistically significant (P＜0.05). Compared with the miR-217 NC group, the number of proliferative cells, migrant cells and invasive cells in the miR-217 mimics group was decreased, and the difference was statistically significant (P＜0.05). The expression of miR-217 was associated with pathological stage of LC and presence or absence of lymph node metastasis (P＜0.05). Conclusion miR-217 regulates the expression of TIMP3, thereby inhibiting the proliferation, migration and invasion of LC cells.