Objective  To investigate the effect of magnetic nanocomposites on proliferation ability of human hepatoma carcinoma (HCC) cells(HepG2 cell line).

  Methods  Leucine-rich repeat-containing G protein-coupled receptor (LGR) 5-small interfering ribonucleic acid (siRNA) was composited with polyethylenimine wrapped superparamagnetic iron oxide nanoparticle (PEI-SPIO) as the gene vector. PEI group was established by transfecting HepG2 cells when cell fusion reached 60% and SI group was established by transfecting HepG2 cells with equivalent simple LGR5-siRNA. Control(Ctrl) group was also established without transfecting. The efficiency of nanocomposites entering cells was scanned with MRI T2. The inhibition rate of cell proliferation was detected by (cell count kit, CCK)-8 assay. The expression level of messenger ribonucleic acid (mRNA) in LGR5 of cells was detected by reverse transcriptase polymerase chain reaction (RT-PCR) and the protein expressions of LGR5 and cyclin D1 were detected by western blotting.

  Results  MRI T2 signal of HepG2 cells in PEI group decreased significantly. Compared with Ctrl group, the inhibition rate of cell proliferation of HepG2 cells in PEI group was significantly increased. The relative expression of LGR5 mRNA and the relative expression of LGR5 and cyclin D1 protein were both significantly decreased (all in P < 0.05), while the corresponding indexes of the cells in SI group had no statistical significance (all in P>0.05).

  Conclusions  Magnetic nanocomposites PEI-SPIO composited with LGR5-siRNA may effectively transfect HepG2 cells. Its mechanism may take effect through down-regulating the expression of cyclin D1 to inhibit the proliferation ability of hepatocellular carcinoma HepG2 cells.