Effect of antimicrobial peptides on proliferation and multidrug resistance in multidrug resistant human hepatocellular carcinoma Bel-7402/ADM cells

  Objective  To evaluate the effect of antibacterial peptides (AMPs) on proliferation and drug resistance in human hepatocellular carcinoma (HC) cells (Bel-7402/ADM) with multidrug resistance for providing evidences to possible application of AMPs in HC treatment.

  Methods  We established a MDR HC cell line with the administration of adriamycin in culture medium with gradient increment and then detected the cells′ sensitivity to chemotherapeutic drugs. The AMPs were extracted from Musca domestica larva. The inhibitive effect of the AMPs on HC was determined with methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay; the effect of AMPs on cell cycle and concentration of intracellular adriamycin was detected with flow cytometry; and the effect of AMPs on the expression of multidrug resistance gene 1 (MDR1) in Bel-7402/ADM cells was determined with reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR).

  Results  Bel-7402/ADM cell line resistant to adriamycin and other chemotherapeutic drugs was established successfully and the resistance index (RI) of the Bel-7402/ADM cells to 5-fluorouracil, vincristine, paclitaxe, and adriamycin were 15.94, 8.45, 8.11, and 10.96, respectively. The 50% inhibitory concentration (IC₅₀) of AMPs against Bel-7402/ADM cells was 463.67 ± 16.93 μg/mL and was lower than that of AMPs against Bel-7402 cells (596.34 ± 19.27 μg/mL). After treatment with AMPs, the proportion of cells in G₀/G₁ phase was significantly increased but the proportion of cells in S phase declined in both Bel-7402 and Bel-7402/ADM cells; the RI of Bel-7402/ADM cells to adriamycin was decreased from 10.69 to 7.10, while the RI of Bel-7402 cells to adriamycin did not changed significantly; the average fluorescence intensity of adriamycin in Bel-7402/ADM cells was increased from 24.16 ± 3.53 to 48.27 ± 5.5, while that of adriamycin in Bel-7402 cells did not increase obviously; the relative expression of MDR1 in Bel-7402/ADM cells was decreased significantly from 1.749 ± 0.020 to 1.071 ± 0.044(t = 24.297, P < 0.001).

  Conclusion  The multidrug resistant human hepatocellular carcinoma Bel-7402/ADM cells are not resistant to AMPs and AMPs could reverse drug resistance of Bel-7402/ADM cells.