To explore the effect and mechanism of circXPO1 on the malignant biological behavior of liver cancer cells.

The expression levels of circXPO1 and miR-195-5p in liver cancer tissues and adjacent tissues were detected by RT-qPCR, and to analyze the correlation between the expression level of circXPO1 and clinicopathological characteristics of patients with liver cancer; liver cancer HCC9204 cells were transfected with si-circXPO1, si-NC, miR-195-5p mimic, miR-NC, si-circXPO1 and miR-195-5p nhibitor, si-circXPO1 and anti-miR-NC respectively, cell proliferation was detected by MTT assay and clonal formation assay, flow cytometry was used to detect cell apoptosis, scratch test was used to detect cell scratch healing rate, dual luciferase reporter test to detect circXPO1 and miR-195-5p targeting relationship. The effect of circXPO1 on the growth of HCC9204 cells in vivo was verified by establishing a nude mouse transplanted tumor model.

Compared with adjacent tissues, the expression of circXPO1 was high (2.14 ± 0.30 vs 0.87 ± 0.13, P < 0.05) and the expression of miR-195-5p was low (0.46 ± 0.08 vs 1.12 ± 0.17, P < 0.05) , and the expression level of circXPO1 was correlated with tumor size, TNM stage and lymph node metastasis (all P < 0.05) . Compared with si-NC or miR-NC, the proliferation inhibition rate [ (56.63 ± 2.13) % vs (0.00 ± 0.00) %, (42.93 ± 1.52) % vs (0.00 ± 0.00) %] and apoptosis rate [ (23.91 ± 1.21) % vs (7.44 ± 0.74) %, (20.02 ± 0.84) % vs (7.40 ± 0.55) %] of HCC9204 cells in si-circXPO1 and miR-195-5p mimic were increased, the scratch healing rate [ (24.02 ± 1.55) % vs (65.54 ± 2.53) %, (34.95 ± 1.69) % vs (65.66 ± 2.68) %] and the number of clones formed [ (53.67 ± 2.16) vs (122.11 ± 5.74) , (72.44 ± 3.69) vs (120.56 ± 8.00) ], the number of invasive cells[ (30.92 ± 5.01) vs (83.06 ± 7.54) , (32.05 ± 4.66) vs (85.43 ± 8.17) ], as well as the tumor volume and mass of nude mice were decreased (all P < 0.05) . circXPO1 targets and regulates miR-195-5p (0.45 ± 0.05 vs 1.03 ± 0.13, P < 0.05) . Compared with si-circXPO1+anti-miR-NC, the proliferation inhibition rate [ (15.22 ± 1.32) % vs (56.37 ± 2.32) %] and apoptosis rate [ (11.96 ± 0.80) % vs (23.81 ± 1.35) %] of HCC9204 cells in si-circXPO1+miR-195-5p inhibitor were decreased, the scratch healing rate [ (48.92 ± 3.15) % vs (23.83 ± 1.55) %] and the number of clones formed [ (108.56 ± 3.86) vs (54.44 ± 2.50) ], the number of invasive cells [ (77.08 ± 7.95) vs (29.65 ± 3.42) ], as well as the tumor volume and mass of nude mice were increased (all P < 0.05) .

Silencing circXPO1 can inhibit the proliferation, migration and invasion of liver cancer cells, promote apoptosis by up-regulating miR-195-5p.