Abstract: Objective: To investigate the influence of P27RF-Rho mRNA gene silencing in the drug sensitivity of 5-fluorouracil(5-Fu)to the liver cancer SMMC cell line,and to provide theoretical basis for the treatment of advanced liver cancer. Methods: The P27RF-Rho RNAi vector was constructed and the P27RF-Rho gene silencing lentivirus were used to infect the SMMC7721 cells. Western blotting method was used to detect the gene silencing effect. The SMMC7721 cells were divided into Scramble-siRNA group, 5-Fu group, P27RF-Rho siRNA group and P27RF-Rho siRNA + 5-Fu group. Western blotting was used to detect the transfection efficiency of RNAi. MTT method was used to detect the cell growth in various groups. Scratching test was used to detect the migration ability of cells in various groups. Transwell experiment were used to detect the invasion ability of cells in various groups. The expressions of P27 and RhoC protein were detected by Western blotting method. Results: P27RF-Rho RNAi lentiviral vector was successfully constructed. The Western blotting results showed that the expression of P27RF-Rho protein in P27RF-Rho siRNA group was decreased compared with 5-Fu group and Scramble-siRNA group(P<0.05). Compared with other three groups, the growth speed of the cells in P27RF-Rho siRNA + 5-Fu group was significantly decreased(P<0.05). The migration ability of the cells in P27RF-Rho siRNA + 5-Fu group was significantly lower than those in other three groups (P<0.01);the average number of cells passing through the Transwell microporous membrane was significantly less than those in other three groups (P<0.01).The Western blotting analysis results showed that the expression level of P27 protein in the cells in P27RF-Rho siRNA + 5-Fu group was significantly higher than those in other three groups(P<0.05);the expression level of RhoC protein was significantly lower than those in other three groups(P<0.05). Conclusion: P27RF-Rho gene silencing can significantly enhance the drug sensitivity of 5-Fu to SMMC7721 cells.

Key words: lentivirus, 5-fluorouracil, drug sensitivity, P27RF-Rho, liver neoplasms