The changes of circulating Tc17 and Treg cells in the patients with colorectal adenoma and the pa-tients with colorectal cancer
Objective To observe the changes of circulating Tc 17 and Treg cells in the patients with colorectal adenoma（CRA）and the patients with colorectal cancer （CRC）and to investigate the correla-tions between them.Methods Peripheral bloods were collected from 63 patients （30 CRA and 33 CRC） and 20 healthy subjects .The proportions of circulating Tc 17 and Treg cells in peripheral blood mononuclear cells （ PBMCs） were detected by flow cytometry .The serum levels of IL-17A and IL-23 were measured by ELISA.Results Compared with healthy controls , the proportions of circulating Tc 17 and Treg cells as well as the serum levels of IL-17 A and IL-23 in CRA and CRC groups were significantly up-regulated （ P〈0.05）.The proportions of circulating Tc17 cells and the serum levels of IL-17A and IL-23 in CRC group were significantly higher than those in CRA group （P〈0.05）, but there was no significant difference in the expressions of Treg cells between the two groups .As the disease progressed , the proportions of circulating Tc17 cells and the serum levels of IL-17A and IL-23 in CRAⅠgroup and the early CRC group were respec-tively higher than those in CRAⅡgroup and the advanced CRC group （P〈0.05）, while the expressions of Treg cells was just the opposite , and no correlation between the expressions of Tc 17 and Treg cells was found （r=-0.227, P=0.073）.Conclusion The changes in the percentage of Tc17 cells in peripheral blood are contrary to Treg cells in patients with CRA or CRC as the disease progresses , but there is no correlation be-tween them . 
 
Key words: 
Colorectal adenoma; Colorectal cancer; Tc17 cell; Treg cell; Cytokine