Effect Of GRP78 On Cisplatin-resistance And Topo-Ⅱ Expression In SMMC-7721 Cells

Objective :Transfect GRP78ASODN into SMMC-7721 cells by LipofectamineTM 2000 to reduce the expression of GRP78mRNA .To observe the impact of GRP78 on SMMC-7721 resistance and Topo-â…¡expression. The results provide new insights into drug resistance of liver cancer.Methods:Using low concentrations of cisplatin (cDDP) short term inducting to produce resistance and transfect GRP78ASODN into SMMC-7721 to reduce the expression of GRP78mRNA,the expression of GRP78mRNA was detected by RT-PCR . screening one of the most effective concentration. Drug sensitivity of parental SMMC-7721 cells,drug-sesistant cells and the transrected cells was detected by MTT assay , obtained IC50 of each group as well as resistance index. Topo-â…¡mRNA expression of each group was detected by RT-PCR.Results:RT-PCR showed that when transfected 100nmol/ml GRP78ASODN, GRP78mRNA reduced to the most significant (P <0.01). The IC50 of drug-resistant cells are significantly higher than parental cells, (P <0.01), after transfection its IC50 decreas significantly (P <0.01). Expression of Topo-â…¡mRNA in drug-resistant group was significantly lower (P <0.01) than parental cells. But transfection group was significantly higher than resistant group (P <0.01).Conclusion :The short low concentrations of CDDP-induced SMMC-7721 cells to produce resistance; GRP78 can enhance SMMC-7721 cells'resistance, and relate with Topo-â…¡; Inhibitting GRP78 can reduce the SMMC-7721 cells'resistant.