RESUMEN
@# Objective: To explore the effect of miR-195/TLR4 axis on the proliferation, invasion and migration of liver cancer cells via regulating NF-κB pathway. Methods: Twenty-five pairs of liver cancer tissues and corresponding adjacent tissues surgically resected at the Second Affiliated Hospital of Kunming Medical University from March 2016 to January 2017 were collected for this study. Liver cancer HepG2 cells were cultured and then randomly divided into four groups: control group (NC), miR-195 mimic group (miR-195), TLR4 knockdown group (si-TLR4), and miR-195 inhibitor combined with TRL4 knockdown group (si-TLR4+miR-195 inhibitor). qRTPCR was used to detect the expression of miR-195 in liver cancer tissues and cell lines. CCK-8 assay was used to evaluate the cell viability of each group. Transwell and Wound healing assay were applied to detect the invasion and migration ability of HepG2 cells, respectively. Dual-luciferase reporter gene assay was used to verify the targeted regulation of TLR4 by miR-195. WB was applied to analyze the protein expressions of TLR4 and NF-κB p65. Results: miR-195 was down-regulated in the liver cancer tissues compared with adjacent tissues (P<0.01). Compared with human hepatic epithelial cells (THLE-3), the expression of miR-193 in liver cancer cell lines (HepG2 and Huh-7) was down-regulated (P<0.01), and the expression level in HepG2 cells was the lowest. The proliferation, invasion and migration of HepG2 cells was significantly suppressed after over-expression of miR-195 (all P<0.01). Moreover, over-expression of miR-195 significantly down-regulated TLR4 protein expression (P<0.05), and TLR4 was negatively correlated with miR-195 (R2= 0.602, P<0.0001). Furthermore, miR-195 over-expression inhibited proliferation, invasion and migration of HepG2 cells by targeting TLR4 expression and blocking NF-κB pathway (P<0.05 or P<0.01). Conclusion: miR-195 over-expression can inhibit the proliferation, invasion and migration of HepG2 cells. The mechanism may be related with targeting TLR4 and blocking the NF-κB pathway to affect cell biological behaviors.