The Imbalance Of Th17/Treg Cells In Patients With Gastric Cancer And Association With Tumor Progression

Objective: To detect expression of Th17and Treg cells in the patientswith gastric cancer, analysis the relationships between Th17/Treg cells, studyits clinicopathological classification, provide experimental and theoreticalbasis to establish an effective new treatment strategies for gastric cancerimmune cells.Methods:1Peripheral blood was collected from45gastric cancer patients and20healthy volunteers. Peripheral blood mononuclear cells (PBMCs) wereobtained by Ficoll-Hypaque density centrifugation of peripheral blood.Expression of Th17and Treg was detected by flow cytometry. Therelationship between Th17, Treg cell distribution and clinical pathologicalfeatures of gastric carcinoma were analized.2Using immunohistochemical staining, detect expression andlocalization CD4~+/IL-17~+T cells and CD4~+/FoxP3~+T cells in gastriccarcinoma and non-cancerous tissue control, tumor regional draining lymphnodes and normal lymph nodes, discuss localization and expression of Th17and Treg cells in gastric cancer tissue.3Fluorescence quantitative RT-PCR was used to assess RORc, IL-17,IL-23, IL-21, IL-22, TGF-β, IL-1β, IL-6, Foxp3, IL-10mRNA expression ingastric cancer and non cancer control tissue, tumor regional draining lymphnodes and non tumor in regional lymph nodes, discuss Th17and Treg cellsimmune balance and its relation to the function and differentiation regulationmechanism in gastric carcinoma tissue.Results:1Flow cytometry analysis results showed that, compared with healthy controls, Th17cell proportion increases significantly in peripheral blood inpatients with gastric carcinoma (1.63±0.10%vs6.67±0.77, P<0.01), andcorrelated with clinical stage (P=0.002), lymph node metastasis (P=0.017), buthad no correlation with patient gender, age, tumor differentiation degree,tumor size, invasion, vascular invasion, Intravascular cancer embolus,preoperative unrelated antigens (P>0.05); Treg number had a significantincrease in patients, and was associated with gastric cancer clinical staging(P=0.034), tumor differentiation (P=0.015), but had no association with gender,age, tumor size, depth of invasion, lymph node metastasis, vascular invasion,Intravascular cancer embolus, preoperative unrelated antigens (P>0.05)；Theratio of Th17/Treg in patients with gastric cancer,(0.65±0.05vs0.34±0.03,P<0.01) was significantly increased (P<0.01), and correlated with lymph nodemetastasis (P=0.036), and had no correlation with patient sex, age, clinicalstage, tumor differentiation, tumor size, invasion, vascular invasion,Intravascular cancer embolus, preoperative unrelated antigens (P>0.05). Th17cells and Treg cells were positively correlated (R=0.64, P=0.003) inperipheral blood of healthy group, but no correlation in the patients withgastric cancer (R=0.12, P=0.49).2Immunohistochemical staining showed that, a large number ofCD4~+/IL-17~+T cells and CD4~+/Foxp3~+T cells were observed in patients withgastric cancer and tumor draining lymph nodes, whereas in the same patienttissues to carcinoma and peritoneal normal lymph nodes were observed no orvery rare CD4~+/IL-17~+T cells and CD4~+/Foxp3~+T cells.3Th17cells related factors was detected by Real-time RT-PCR, theresults show that, compared with non cancer control tissues, RORc, IL-17,IL-21, TGF-β, IL-6, Foxp3, IL-10mRNA expression levels increasedsignificantly in gastric cancer tissues; compared with normal lymph nodes,RORc, IL-17, IL-23, IL-21, TGF-β, IL-1β, IL-6, Foxp3, IL-10mRNAexpression level was significantly elevated in gastric regional draining lymphnodes, but IL-22mRNA expression levels were not significantly different. Ingastric cancer,expression of RORc mRNA has significant correlation with the level of IL-17, IL-21, TGF-β, IL-1β mRNA expression, expression ofFoxp3mRNA has significant correlation with the level of TGF-β mRNAexpression. In gastric regional draining lymph nodes, RORc mRNAexpression levels and IL-17, IL-21, TGF-β, IL-1β, IL-6mRNA expressionlevels have obvious correlation, Foxp3levels expression obvious correlatedwith IL-10, TGF-β mRNA expression levels.4The correlation analysis of RORc and Foxp3mRNA expression levelsrevealed, RORc and Foxp3mRNA expression was not significantly correlatedin gastric cancer tissues and regional draining lymph nodes.5The analysis results of relationship between RORc, Foxp3mRNAexpression levels in patients with gastric cancer and clinical and pathologicalcharacteristics show that, RORc and Foxp3mRNA expression level correlatedwith TNM stage (P=0.008, P=0.032), and had no correlation with otherclinical indices (P>0.05).Conclusions:1Th17cells, Treg cells, and the radio of Th17/Treg increased in patientswith gastric cancer, correlated with the patients with TNM staging, lymphnode metastasis, tumor differentiation, suggesting that Th17/Treg immuneimbalance was presenced in patients with gastric cancer, this imbalance maypromote the progression of gastric cancer and affect the prognosis of thepatients.2Th17cells promote gastric cancer progression may related withsecreting IL-17, IL-21. Accumulation of Th17cells related with TGF-β, IL-6promote Th17cells differentiation in tumor microenvironment. Treg cellssecret inhibition of factor IL-10, TGF-β which help the gastric cancer cellsescape from the host antitumor immune response system, so as to promote theformation and development of gastric carcinoma.