LncRNA RUNXOR In Lung Cancer Patients Regulates The Immunosuppressive Function Of MDSCs

Objective:To investigate whether long noncoding RNA(lncRNA)RUNXOR carried by lung cancer patients has regulatory effect on the immunosuppression function of myeloid-derived suppressor cells(MDSCs).Methods:(1)Flow cytometry(FCM)was used to detect CD11b~+CD33~+HLA-DR~-CD14~-MDSCs and CD3~+CD8~-IFN-?~+Th1 cells and CD3~+CD8~+IFN-?~+CTL cells in peripheral blood of lung cancer patients and healthy donors.(2)MDSCs in peripheral blood both from healthy donors and lung cancer patients before and after surgery have been selected.Then use IL-1?and GM-CSF to distill MDSCs from healthy donors'peripheral blood mononuclear cells.Separate MDSCs from tumor tissues and adjacent tissues of lung cancer patients,then,use qRT-PCR detection to test the expression of RUNXOR and RUNX1 in these MDSCs.(3)The specific siRNA was used to knock down the expression of RUNXOR in the sorted and induced MDSCs.(4)The colorimetric method was used to detect the activity of arginase 1(Arg1)in MDSCs from peripheral blood of both lung cancer patients and healthy donors,and the activity of Arg1 in MDSCs,which after knockdown RUNXOR,from lung cancer tissues of lung cancer patients.(5)Finally,qRT-PCR was used to determine the expression of RUNX1 in these MDSCs after knockdown.Results:(1)In the peripheral blood of patients with lung cancer,the proportion of MDSCs increased(p<0.001),and the proportion of Th1 cells and CTL in lung cancer patients decreased(p<0.01).The proportion of MDSCs in peripheral blood was negatively correlated with the percentage of Th1/CTL.(2)The RUNXOR level in peripheral blood of patients with lung cancer increased(p<0.001),and RUNXOR was differentially expressed between lung squamous cell carcinoma and lung adenocarcinoma(p<0.05).The expression of RUNXOR in peripheral blood of patients with lung cancer after surgical resection of lung cancer was significantly decreased(p<0.05).The expression of RUNXOR in MDSCs in MDSCs isolated from adjacent tissues(p<0.05).(3)Specific siRNA was used to inhibit the expression of RUNXOR,and the level of Arg1 in MDSCs in tumor tissues was significantly down-regulated(p<0.01).It can be seen that the level of lncRNA RUNXOR is closely related to MDSCs function.PBMCs from healthy volunteers could be induced into MDSCs by GM-CSF and IL-1?system.Compared with PBMCs,RUNXOR expression was significantly increased in MDSCs(p<0.001).After MDSCs knocked down RUNXOR,Arg1expression was significantly decreased(p<0.01).(4)Compared with healthy donors,lung cancer patients had lower RUNX1 levels(p<0.001).The expression of RUNX1 in MDSCs,MDSCs induced by GM-CSF and IL-1?from tumor tissues of lung cancer patients decreased in the tumor tissues(p<0.05).The expression of RUNX1 was negatively correlated with the ratio of MDSCs in peripheral blood of patients with lung cancer(p<0.05).The expression of RUNX1 in peripheral blood of patients with postoperative lung cancer increased(p<0.001).After RUNXOR knockout,MDSCs isolated from lung cancer tissues and MDSCs induced from PBMCs increased RUNX1 expression(p<0.001).Conclusions:In summary,the LnRNA RUNXOR of lung cancer patients has a significant correlation with the immunosuppressive function of MDSCs.Inhibiting the expression of lncRNA RUNXOR in MDSCs of lung cancer patients can attenuate the immunosuppressive function of MDSCs.