Synergistic effect of interventing insulin-like growth factor-Ⅰ receptor activation combined with anti-cancer drugs in inhibiting the proliferation of hepatocellular carcinoma cells

Objective To investigate the intervention of gene transcription of insulin- like growth factor- Ⅰ receptor( IGF- ⅠR) and its synergistic effect with anti- cancer drugs in inhibiting the proliferation of hepatocellular carcinoma( HCC) cells. Methods The HBV-positive HCC PLC / PRF /5 and HBV- negative Bel- 7404 cells were transfected with the efficient plasmid p GPU6 / GFP / Neo- IGF- ⅠR-shRNA. Fluorescent quantitative RT- PCR and Western blot were used to measure mRNA and protein expression,the Cell Counting Kit-8 was used to analyze cell proliferation,and flow cytometry and Annexin- V- PE /7- ADD were used to analyze cell cycle and apoptosis.The t- test was used for comparison of continuous data between groups,the Fisher's exact test was used for comparison of categorical data between groups. Results The efficiency of IGF-ⅠR shRNA transfection was 71% in HCC PLC / PRF /5 cells and 90% in Bel- 7404 cells,and both cells showed reductions in the mRNA and protein expression of IGF- ⅠR. The intervention group showed a significant inhibition compared with the negative control group,and the 72- hour inhibition rates of Bel- 7404 cells and PLC / PRF /5 cells showed significant differences between the two groups( inhibition rates of Bel- 7404 cells: 61. 5% ± 1. 7% vs 11. 2% ± 0. 9%,t = 5. 493,P < 0. 05; inhibition rates of PLC / PRF /5 cells: 63. 9% ± 3. 9% vs 9. 5% ± 1. 1%,t = 19. 244,P < 0. 001). The intervention group showed a significantly higher apoptosis rate of Bel- 7404 cells than the blank control group( 35. 96% vs 12. 16%,P < 0. 001) and the negative control group( 35. 96% vs 9. 43%,P < 0. 001),as well as a significantly higher apoptosis rate of PLC/PRF/5 cells than the blank control group( 44. 84% vs 6. 62%,P < 0. 001) and the negative control group( 44. 84% vs 4. 02%,P < 0. 001). The co- intervention group showed significantly higher percentages of Bel- 7404 cells and PLC / PRF /5 cells in G0/ G1 phase than the negative control group( 59. 0% ± 1. 3%vs 48. 4% ± 0. 8%,t = 12. 032,P < 0. 001; 65. 4% ± 0. 5% vs 53. 5% ± 0. 7%,t = 22. 789,P < 0. 001). The co- intervention group showed significantly lower expression of cyclin D1 in Bel- 7404 cells and PLC / PRF /5 cells than the negative control group( 59. 6% ± 4. 7%vs 90. 0% ± 3. 4%,t = 7. 389,P < 0. 05; 39. 9% ± 0. 5% vs 90. 2% ± 14. 6%,t = 4. 876,P < 0. 05). The OD value of Bel- 7404 cells and PLC / PRF /5 cells showed a significant difference between the intervention group and the negative control group when the sorafenib concentration was 0,2. 5,5,10,and 20 nmol / L and the oxaliplatin concentration was 0,5,10,20,and 40 μmol / L( all P < 0. 05). Conclusion The downregulation of IGF-ⅠR gene transcription has the synergistic effect of inhibiting HCC cell proliferation and improving drug susceptibility.