The populations, distribution of regulatory T cells, Foxp3 mRNA expression gastric cancer patients and the association with malignant stage

Abstract

Objective To investigate the populations of CD+4CD25high Foxp3+ regulatory T cells(Treg cells)and mRNA expression of Foxp3 in peripheral and the marginal region of tumor from patients with gastric cancer,and to evaluate the prevalence of Treg cells from patients with gastric cancer in relation to the TNM stages.Methods PBMC,Ascites,tumor-infiltration lymphocyte and tumor-draining lymph nodes in 47 patients with gastric cancer(TNM I11,Ⅱ18,Ⅲ10,Ⅳ8)and PBMC in 20 normal healthy donors were evaluated for the proportion of Treg cells,as a percentage of the total CD4+ cells,by flow cytometric analysis.Levels of mRNA for Foxp3 were measured witll a real-time quantitative PCR Results The percentage of CD4+CD25high Foxp3+ Treg cells in PBMC for cases of gastric cancer were significantly higher than those for healthv donors(P<0.05).The percentage of Treg cells were more abundant in ascites(P< O.05),1rIL(P<0.01)and tumor-draining lymph nodes(P<0.01)of individuals with gastric cancer than in their blood.And the Foxp3 mean fluorescent intensity (MFI) of Treg cells in TIL and tumor draining lymph nodes with gastric caners were significantly higher than PBMC and ascites(P<0.05).The proportion 0f Treg cell in patients of gastric cancers with stage I,II,Ⅲ,Ⅳ were(5.72±1.95)%,(6.45± 2.23)%,(9.58±3.13)%,(11.70±2.30)%,respectively.There were significant correlation between Drevalenee of Treg cells and disease stages in gastric cancer(r=0.784,P<0.01).Foxp3 mRNA levels were higher in PBMC from the group with gastric cancers than in the group with healthy donors.Foxp3 mRNA levels were correlated with TNM stages(r=0.623,P<0.05).Conclusions Our results suggest that the populations of CD4+CDhigh25 Foxp3+Treg cells and Foxp3 mRNA levels in patients with gastric cancer are signifieantlv higher in comparison to those in control donors.In addition,the expression of Fox：p3 mRNA increased with tumor stage.The increased prevalence of Treg cells may be one of the explanations for impaired cell-mediated immunity in cancer bearing hosts. Key words: Stomach neoplasms; Neoplasm staging; DNA-binding proteins; T-lymphocytes