Abstract: Objective  To investigate the effect of miR-145-5p targeting LOX on the invasion and migration of liver cancer cells and its mechanism. Methods The cancer tissues and adjacent normal tissues from 73 patients who underwent hepatobiliary surgery in Guangxi Medical University Cancer Hospital from September 2017 to September 2019, and liver cancer cell lines SMMC-7721 and SK-Hep1 were collected. The expressions of miR-145-5p and LOX in tissues were detected by RT-PCR. The miR-145-5p lentiviral vector, LOX overexpression plasmid and LOX lentiviral silencing vector were transfected with liver cancer cells SMMC-7721 or SK-Hep1; the LOX overexpressed plasmid and miR-145-5p lentivirus vector were co-transfected with SMMC-7721 cells; a corresponding negative control group and a blank control group were set in each transfection group. The migration and invasion ability of liver cancer cells were detected by Transwell assay; the expression level of LOX protein was detected by Western blot; The target of miR-145-5p was predicted by TargetScan database; and the GO and KEGG enrichment were analyzed by Cluster Profiler package. Results The results of qRT-PCR showed that miR-145-5p expression in adjacent normal tissues was higher than that in liver cancer tissues(4.196±2.288 vs 2.835±1.817, P<0.0001). The expression of LOX in liver cancer tissues was higher than that in adjacent normal tissues(12.17±1.369 vs 11.26±1.556, P<0.001). Transwell assay showed that the overexpression of LOX could promote the invasion and migration of liver cancer cells, while the knockdown of LOX inhibited the invasion and migration of liver cancer cells (all P<0.001). The overexpression of miR-145-5p could inhibit the invasion and migration of liver cancer cells, and the overexpression of LOX reversed the inhibitory ability of miR-145-5p on migration and invasion of SMMC-7721 cells. TargetScan database prediction showed that LOX was the target gene of miR-145-5p. Western blot showed that miR-145-5p could inhibit LOX protein expression (P<0.001). Conclusions miR-145-5p is lowly expressed in liver cancer tissues, while LOX is highly expressed. miR-145-5p may inhibit the invasion and migration of liver cancer cells by negatively regulating LOX.

Key words:  Liver cancer, miR-145-5p, LOX, Invasion, Migration