Effects of hydroxyapatite nanoparticles on proliferation and apoptosis of human hepatoma BEL-7402 cells

AIM:To study the effect of hydroxyapatite(HAP)nanoparticleson human hepatoma cell line BEL-7402 in vitro.METHODS:The human hepatoma cell line BEL-7402 wascultured and treated with HAP nanoparticles at variousconcentrations.Growth suppression was detected with MTTcolorimetric assay,cell apoptotic alterations were evaluatedby cytochernical staining(Hoechst 33258),transmissionelectron microscopy(TEM),and flow cytometry(FCM).RESULTS:HAP nanoparticles inhibited the growth ofhepatoma cells in a dose-dependent manner,with IC50valuesof 29.30 mg/L.Treated with 50-200 mg/L HAP nanoparticlesfor 48 h,BEL-7402 cells apoptosis with nuclear chromatincondensation and fragmentation as well as cell shrinkageand the formation of apoptotic bodies were observed undercytochemical staining and transmission electron microscopy.FCM analysis showed hypodiploid peaks on histogram,theapoptotic rates at the concentrations of 50,75,100,150and 200 mg/L of HAP nanoparticles were 20.35±2.23 %,25.35±1.92 %,29.34±4.61%,44.92±3.78 % and53.64±3.49 %,respectively,which were all significantlyhigher than that of control group 2.23±0.14 %.There wasa significant correlation between HAP nanoparticleconcentration and apoptotic rate(r=0.994,P<0.01).CONCLUSION:HAP nanoparticles not only inhibitproliferation but also induce apoptosis of human hepatomacell line BEL-7402 in vitro.