甘草甜素通过PI3K/AKT/NF-κB信号轴抑制ABCB1逆转前列腺癌化疗耐药的机制研究OA北大核心CSTPCD

Objective:To investigate the molecular mechanism of glycyrrhizin reversing chemoresistance in prostate cancer(PCa)through regulating ABCB1.Methods:The PCa chemotherapy-sensitive strains C4-2B,DU145 cells and the corresponding chemotherapy-resistant strains TaxR,DU145R were cultured.The resistance of four types of cells to docetaxel(DTX)was detected by CCK-8 assay and colony formation assay,and the expression of ABCB1 protein was detected by Western Blotting.TaxR and DU145R cells were divid-ed into the following groups:(1)normal control group,NC group,siABCB1-1 group,siABCB1-2 group.The efficiency of ABCB1 silen-cing by small interfering RNA(siRNA)was confirmed by Western Blotting,the differences in DTX resistance among the groups were detected by the CCK-8 assay.(2)Cells were treated with different concentrations of glycyrrhizin(0,0.25,12.5,25,50,100,200,400,600,800 μmol/L).The CCK-8 assay was used to select the subsequent administration concentrations(100,200,400 μmol/L).The key proteins expressions of ABCB1 and PI3K/AKT/NF-κB signaling pathway were detected by Western Blotting,the function of the ABCB1 transporter was assessed using the Rhodamine 123 assay.(3)The cells were divided into normal control group,DTX(TaxR cells:20 nmol/L;DU145R cells:10 nmol/L)group,glycyrrhizin(100 μmol/L)group,glycyrrhizin with DTX group.Apoptosis rate and cell cycle were analyzed by flow cytometry,the expressions of apoptosis-related proteins(Bcl-2,BAX,c-Caspase-3)were detected by Western Blotting.(4)The cells were divided into normal control group,glycyrrhizin(100 μmol/L)group,740Y-P(20 μmol/L)group,glycyrrhizin with 740Y-P group.The expressions of PI3K,Akt,ABCB1 proteins were detected by Western Blotting.(5)The cells were divided into normal control group,glycyrrhizin(100 μmol/L)group,PI3K inhibitor wortmannin(WM,100 μmol/L)group,glycyrrhizin with WM group.The expressions of PI3K,Akt,ABCB1 proteins were detected by Western Blotting.(6)The cells were divided into nor-mal control group,BAY(10 μmol/L)group,glycyrrhizin(100 μmol/L)group,glycyrrhizin with BAY group.The expressions of NF-κB p65,p-iκBα,ABCB1 proteins were detected by Western Blotting.Results:The ABCB1 protein expression in resistant cells was signifi-cantly upregulated(P<0.01),its silencing enhanced DTX sensitivity.Glycyrrhizin inhibited the expression of ABCB1 protein and the viabilities of TaxR,DU145R cells in a concentration-dependent manner,increased the accumulation of rhodamine in cells,enhanced the effect when combined with DTX,and could increase the expressions of Bax and Caspase-3 proteins in cells and reduced the expression of Bcl-2 protein and induced G1 phase block(P<0.05 or P<0.01).Mechanism studies showed that glycyrrhizin down-regulated the ex-pression of ABCB1 protein by inhibiting the PI3K/AKT/NF-κB pathway.PI3K inhibitors WM and NF-κB inhibitors BAY enhanced the effect of glycyrrhizin,and PI3K activator 740Y-P could reverse the effect of glycyrrhizin(P<0.05 or P<0.01).Conclusion:Glycyrrhizin inhibits the expression of ABCB1 by targeting the PI3K/AKT/NF-κB signaling axis,effectively reversing chemotherapy resistance in prostate cancer.