Effect of high glucose on immune escape of pancreatic cancer cells by regulating miR-429/ZEB1 axis
Objective To explore the impact of high glucose(HG)intervention on immune escape of pancreatic cancer cells and its molecular mechanisms.Methods PANC-1 cells were treated with different concentrations of glucose(0,7.5,15,30 mmol/L)for 24 h to establish high glucose intervention PANC-1 cells.miR-429 mimics and its negative control(mimics NC)were transfected into PANC-1 cells,which were divided into control group,HG group,HG+mimics NC group,HG+mimics group,HG+mimics+oe-NC group,and HG+mimics+oe-ZEB1 group.Flow cytometry was utilized to measure the expression level of cell surface molecule PD-L1;qRT-PCR was used to detect the expression levels of miR-429 and ZEB1 mRNA in cells;Western blot was used to detect the ex-pression level of ZEB1 protein in cells.The above-mentioned PANC-1 cells from each group were co-cultured with CD8+T cells to establish a co-culture system,and CCK-8 was used to assess cell proliferation activity;apoptosis levels of cells were measured using flow cytometry;lactate dehydrogenase(LDH)release assay was used to detect the killing effect of CD8+T cells on PANC-1 cells;dual-luciferase reporter system was used to validate the target-regulatory relationship between mi R-429 and ZEB1.Results HG could promote the expression of cell surface mole-cules PD-L1 and ZEB1 in PANC-1 cells(P<0.05),inhibit the expression of miR-429,and exhibit concentration dependence.Overexpression of miR-429 could significantly suppress the expression of cell surface molecule PD-L1 induced by HG in PANC-1 cells,while overexpression of ZEB1 could reverse the inhibitory effect of miR-429 over-expression on the expression of cell surface molecule PD-L1 induced by HG.After establishing a co-culture system with CD8+T cells,compared with the control group,the proliferation activity of PANC-1 cells in the HG group sig-nificantly increased,and the apoptosis rate and cytotoxicity significantly decreased(P<0.05).Compared with the HG+mimics NC group,the proliferation activity of PANC-1 cells in the HG+mimics group significantly decreased,and the apoptosis level and cytotoxicity significantly increased(P<0.05).Compared with the HG+mimics group,the proliferation activity of PANC-1 cells in the HG+mimics+oe-ZEB1 group significantly increased,and the apop-tosis rate and cytotoxicity significantly decreased(P<0.05).Dual luciferase reporter gene assay confirmed that miR-429 negatively regulated ZEB1.Conclusion High glucose promotes immune escape of PANC-1 cells by down-regulating the expression level of miR-429,negatively regulating the expression of ZEB1 mRNA,and increasing the expression level of cell surface molecule PD-L1 in PANC-1 cells.
mi R-429pancreatic cancerzinc finger E-box binding homeobox protein 1high glucoseimmune es-cape