Objective To investigate the expression of caspase-3 in xenograft that was treated with targeted therapy with magnetic nanoparticles in nude mice. Methods QBC939 cell lines were injected into nude mice subcutaneously to establish the model of human cholangiocarcinoma xenograft. After two weeks of tumor inoculation, the animal models were divided randomly into 4 groups: group A received placebo (sodium chloride), group B were treated with magnetic nanoparticles (250 mg/kg), group C were treated with magnetic nanoparticles (150 mg /kg) combined with inner-stent, group D with magnetic nanoparticles (250 mg /kg) combined with inner-stent (the inner-stent was used to generate the magnetic targeting effect). The 21th day after treatment, expression of caspase-3 in tumor cells of each groups were measured with histochemical method and RT-PCR. Results The quantity of caspase-3 in tumor cells that were treated with magnetic nanoparticles (250 mg/kg) combined with inner-stent was the most (P＜0.05), and the quantity of caspase-3 in cells of group C was significantly more than that of the other two groups (P＜0.05). While the quantity of caspase-3 in group B was more than that of the control group(P＜0.05). Conclusion The use of magnetic nanoparticles combined with inner-stent may increase the expression of caspase-3, and the expression is dose-dependent with magnetic nanoparticles.
【Abstract】ObjectiveTo study the effect of transfection with antisense DNMT3b gene eukaryotic expression vector on the expression of DNMT3b gene in human cholangiocarcinoma cell line QBC-939. MethodsThe constructed antisense DNMT3b gene eukaryotic expression vector was transfected into the human cholangiocarcinoma cell line QBC-939 by using lipofectamine transfection reagents, and positive cell clones were obtained by using G418 selection after transfection. Whether the constructed recombinant vector was transfected into QBC-939 cells successfully was confirmed by amplifying the exogenous neoR gene with PCR method. The expression of DNMT3b gene mRNA and protein were detected by semi-quantitative RT-PCR and FCM methods respectively. ResultsFollowing the transfection of antisense DNMT3b gene eukaryotic expression vector, the mRNA level of DNMT3b gene in QBC-939 cells of human cholangiocarcinoma decreased from 0.956±0.053 to 0.209±0.023, and the protein level of DNMT3b gene also decreased from (75.38±3.22)% to (29.87±3.46)%. There were very significant differences on the expression levels of DNMT3b gene between non-tranfections group and the antisense DNMT3b gene eukaryotic expression vector transfection group (P＜0.01). ConclusionTransfection with antisense DNMT3b gene eukaryotic expression vector significantly reduces the expression level of DNMT3b gene in human cholangiocarcinoma cell line QBC-939, and this study may provide a valid tool and method to investigate the function of DNMT3b gene and its role in cholangiocarcinoma.