Objective:To investigate the effects of augmenter of liver regeneration(hALR) in cisplatin(cDDP) induced human hepatocellular carcinoma drug-resistant cells(HepG2/cDDP) on the expression of cytochrome P450

and detect whether ALR has relationship with the drug resistance of human hepatocellular carcinoma cells by affecting CYP540.Methods: A drug resistant human hepatoma cell line(HepG2/cDDP) induced by cisplatin was established in vitro

and its resistance index was evaluated by MTT assay.The expressing siRNA plasmid psiALR-A targeting hALR and the unrelated control plasmid psiALR-B were constructed successfully and transfected into HepG2/cDDP cells with lipofectamine 2000 methods

respectively;the expression of green fluorescent protein was observed under a fluorescence microscope to calculate transfection efficiency.According to different plasmid transfection

HepG2/cDDP cells were divided into three groups: transfection group(transfected psiALR-A)

control group(transfected psiALR-B)

and blank control group(non-transfected with the recombinant plasmid).The protein and mRNA level of hALR and CYP450 in each group of cells were measured by immunocytochemistry

Western Blot and Real-time FQ-PCR.The activities of CYP450 in each group of cells were detected by chemiluminescence;drug sensitivity to cDDP in each group cells was detected by MTT assay.Results: HepG2/cDDP cell line was established successfully with stable resistance to cDDP

and the resistance index(RI) was 6.26.Plasmid psiALR-A targeting hALR and the unrelated control plasmid psiALR-B were transfected successfully.In transfection group

the level of hALR protein and mRNA expression decreased significantly

but the level of CYP450 protein and mRNA expression increased significantly.In the control group and blank control group

there was no obvious change.The activities of CYP450 were increased significantly and the sensitivity to cDDP was decreased in transfection group;however

there was no obvious change in the control group and blank control group.Conclusion: The level of CYP450 expression and the activities of CYP450 are increased significantly

but the sensitivity to cDDP is decreased in transfection group.ALR may play an important role in the occurrence and development of the drug resistance of hepatocellular carcinoma cells.