Effect of downregulating proline-rich protein 11 expression on drug resistance of esophageal cancer drug resistant cell EC9706/DDP and its mechanism / 吉林大学学报(医学版)

ABSTRACT

Objective:To discuss the effect of downregulating the proline-rich protein 11(PRR11)expression on drug resistance of the esophageal cancer drug resistant cells,and to clarify the related mechanism.Methods:The drug resistant cells EC9706/cisplatin(DDP)were established by incrementally stimulating the human esophageal cancer EC9706 cells with the increasing concentrations of DDP.The drug sensitivity of the EC9706/DDP cells was detected by MTT assay;the expression levels of PRR11 mRNA and protein in the EC9706/DDP cells and their parent EC9706 cells were detected by real-time fluorescence quantitative PCR(RT-qPCR)and Western blotting methods.The EC9706/DDP cells were divided into control group,sh-NC group(infected with sh-NC),sh-PRR11 group(infected with sh-PRR11),sh-NC+DDP group(infected with sh-NC and treated with 4 mg·L-1 DDP),and sh-PRR11+DDP group(infected with sh-PRR11 and treated with 4 mg·L-1 DDP).The expression levels of PRR11 mRNA in the cells in various groups were detected by RT-qPCR method;the expression levels of PRR11,phosphoinositide 3-kinase(PI3K)p110α,protein kinase B(AKT),phosphorylated AKT(p-AKT),P-glycoprotein(P-gp),and multidrug resistance-associated protein 1(MRP1)proteins in the cells in various groups were detected by Western blotting method;the apoptotic rates of the cells in various groups were detected by flow cytometry.Results:The DDP-resistant cell line EC9706/DDP was successfully obtained,and the drug resistance index was 7.23±0.86.Compared with the EC9706 cells,the expression levels of PRR11 mRNA and protein in the EC9706/DDP cells were increased(P<0.05).Compared with control and sh-NC groups,the expression levels of PRR11 mRNA and protein in the cells in sh-PRR11 group were decreased(P<0.05),and the 50%inhibitory concentration(IC50)of DDP was decreased(P<0.05).Compared with sh-NC group,the expression levels of PI3K p110α,p-AKT,P-gp,and MRP1 proteins in the cells in sh-NC+DDP and sh-PRR11 groups were decreased(P<0.05),and the apoptotic rate of the cells was increased(P<0.05).Compared with sh-NC+DDP group and sh-PRR11 group,the expression levels of PI3K p110α,p-AKT,P-gp,and MRP1 proteins in the cells in sh-PRR11+ DDP group were increased(P<0.05),and the apoptotic rate of the cells was increased(P<0.05).Conclusion:Downregulating the expression of PRR11 gene in the drug resistant EC9706/DDP cells can inhibit the expressions of drug resistance-related proteins,reverse the resistance to DDP,and induce the apoptosis;its mechanism may be related to the inhibition of activation of the PI3K/AKT signaling pathway.