Reversal Of The Primary Multidrug Resistance Of Retinoblastoma HXO-RB₄₄ Cells By Ginsenoside Rg3

Objective: To study the effects of innocurity toxicity doses of gensenoside Rg3 on chemotherapeutic drugs (VCR, HTT) for reverse primary multidrug resistance of HXO-RB44 cells,and get its possible mechanism.methods: The research was divided into 3 groups.Groupl (Getting innocurity toxicity dose of GRg3 group),Mtt was applied to determine the cytotoxicity of GRg3 (10³,10²,10,1,0.1μmol/L),to get innocurity toxicity dose of GRg3; than mmunocytochemica was applied to observe the change of MRP in HXO-RB44 cells,which is cultured by this dose of GRg3 for 48 hours.Group2(VCR group):HXO-RB₄₄ cells cultured by VCR(10³,10², 10,1,0.1μmol/L) and 0.1μmol/L (innocurity toxicity dose) GRg3 for 48 hours,comparing with cultured by VCR only.Group3(HTT group):HXO-RB₄₄ cells cultured by HTT (10³,10²,10,1,0.1μmol/L) and 0.1μmol/L GRg3 for 48 hours,comparing with cultured by HTT only.MTT was applied to determine the cytotoxicity of Group2, Group3 espectively, to get inhibitory rate of HXO-RB₄₄ cells and IC₅₀ in each groups.By comparing with inhibitory rate of HXO-RB₄₄ cells and IC₅₀ in each groups and the modality changes of HXO-RB₄₄ cells with converted microscope.Results: Innocurity toxicity dose of GRg3(Groupl) is 0.1μmol/L, which inhibitory rate of HXO-RB₄₄ cells is 3.19%;and GRg3 can inhibit growth of HXO-RB₄₄ cells,which its concentration above 1μmol/L. Immunocytochemical results showed overexpression of MRP in HXO-RB₄₄ cells,after HXO-RBa4 cells was pretreated with 0.1μmol/L GRg3 for 48 hours,MRP expression in HXO-RB₄₄ cells is reduced significant.The inhibitory rate of HXO-RBa4 cells of VCR were lower than of that VCR mixed with 0.1μmol/L GRg3 (Group2),and the IC50 were enhanced. The inhibitory rate of HXO-RB₄₄ cells of HTT were lower than of that HTT mixed with 0.1μmol/L GRg3 (Group3),and the IC50 were enhanced.There are statistical significant differences in the inhibitory rate and IC₅₀ among every group.Under the coverted microscope ,the modality changes of HXO-RBa4 cells in groups mixed with innocurity toxicity dose of GRg3 were quite different from that with chemotherapeutic drugs alone.Conclusions: GRg3(concentration＞1μmol/L) can inhibit growth of HXO-RB₄₄ cells.GRg3(0.1μmol/L) can reduce MRP expression in HXO-RB₄₄ cells. GRg3(0.1μmol/L) can enhance the inhibitory effects of VCR, HTT in HXO-RB44 cells,and its possible mechanism is that reduce MRP expression,reverse primary multidrug resistance of HXO-RB₄₄ cells.