miR-217靶向调控ERK2表达对非小细胞肺癌细胞活性和免疫逃逸的影响及机制研究OA北大核心CSTPCD

Objective:To investigate the effect and mechanism of miR-217 targeted regulation of extracellular signal-regulated kinase 2(ERK2)expression on activity and immune escape of non-small cell lung cancer cells(NSCLC).Methods:qRT-PCR was used to detect expression levels of miR-217 and ERK2 mRNA in NSCLC tissues,adjacent tissues,and HLF-1,A549 and HCC827 cell lines.Analyzed prognosis and survival status of NSCLC patients with different miR-217 expression level.Bioinformatics and dual luciferase gene reporting experiments were used to analyze the targeting relationship between miR-217 and ERK2.Cultivated NSCLC A549 cells and divided them into NC group,miR-217 inhibitor group,miR-217 mimic group,miR-217 mimic+ERK2 NC group and miR-217 mimic+ERK2 group.Except for the NC group without any treatment,all other groups were transfected with corresponding plasmids to analyze the proliferation activity and immune escape status of A549 cells in each group,and clarified the mechanism of action.Results:Compared with adjacent tissues,expression of miR-217 in NSCLC tissue was decreased,while expression of ERK2 mRNA was increased(P<0.05).Compared with human normal lung fibroblast HLF-1 cell lines,expression of miR-217 in NSCLC cell lines A549 and HCC827 were decreased,while expression of ERK2 mRNA was increased(P<0.05).Analysis of the relationship be-tween miR-217 and prognosis of NSCLC patients based on Kaplan-Meier Plotter database showed that low expression of miR-217 was associated with poor prognosis of patients(HR=0.90,P=0.033).Dual fluorescein reporter genes showed matching sequences between the 3'UTR regions of miR-217 and ERK2.miR-217 mimic fragment could inhibit ERK2-WT signal,but had no effect on ERK2-MUT.Compared with NC group,cell proliferation activity,PD-L1 and PD-L2 mRNA expression levels of miR-217 inhibitor group were in-creased,while CD8+T cell activity was decreased,and cell proliferation activity,PD-L1 and PD-L2 mRNA expression levels of miR-217 mimic group were decreased,while CD8+T cell activity was increased(P<0.05).Compared with miR-217 mimic group,cell pro-liferation activity,CD8+T cell activity,PD-L1 and PD-L2 mRNA expression levels of miR-217 mimic+ERK2 NC group had no signifi-cant changes(P>0.05),cell proliferation activity,PD-L1 and PD-L2 mRNA expression levels of miR-217 mimic+ERK2 group were increased,while CD8+T cell activity was decreased(P<0.05).Conclusion:Overexpression of miR-217 can reduce the activity of NSCLC cell A549,inhibit the expression of PD-L1,activate CD8+T cells in tumor microenvironment,and then inhibit immune es-cape,which may play a role by targeting ERK2.