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 .

Objective To compare ratio of circulating Th17 over Tc17 cells in patients with colorectal polyp (CRP), colorectal adenoma (CRA) and colorectal cancer (CRC),and analyse their relationship. Methods The ratio of circulating Th17 over Tc17 cells in 93 patients(17 CRP, 34 CRA and 42 CRC)and 17 healthy donors were examined by flow cytometry;Serum levels of IL-17A and IL-23 were tested by ELISA. Results The ratio of circulating Th17 over Tc17 cells and the se-rum levels of IL-17A and IL-23 were the lowest in healthy control groups, medium in CRP and CRA groups and the highest in CRC groups (P＜0.05). The proportions of Tc17 cells in CRA groups were significantly higher compared to those in CRP groups,but no statistical significance of proportion of circulating Th17 cells as well as serum levels of IL-17A and IL-23 be-tween CRA and CRP groups was observed (P>0.05). Further analysis showed that there was a positive correlation between proportions of circulating Th17 and Tc17 cells (rs=0.594, P＜0.001). Conclusion The proportions of circulating Th17 and Tc17 cells were positively related and the ratio of Th17 over Tc17 was markedly increased from CRP group or CRA group to CRC group.

Objective:To explore the changes and possible mechanisms of circulating Tc 17 cells in patients with colorectal cancer ( CRC) following disease progression .Methods:The peripheral blood were collected from 54 patients with colorectal cancer . the proportions of Tc17 cells in peripheral blood mononuclear cells (PBMCs) and cultured PBMCs treated by IL-1β, IL-6 and TGF-βin different concentrations were determined by flow cytometry;the levels of IL-1β, IL-17A, IL-23 and IL-6 in sera were measured by ELISA.Results:The proportions of Tc17 cells and the levels of IL-1β, IL-17A, IL-23 and IL-6 were significantly higher than those in healthy controls (P<0.05).Compared with early CRC, the proportions of Tc17 cells and the levels of IL-1β, IL-17A in advanced CRC were significantly decreased, but the level of IL-6 was significantly increased (P<0.05).The difference of IL-23 level between early and late groups was not significant (P>0.05).In vitro experiments confirmed that IL-1βor high concentrations of IL-6 and TGF-βcould significantly increase the number of Tc 17 cells in PBMCs.Conclusion: The changes of circulating Tc 17 cells in the progression of colorectal cancer are possibly modulated by IL-1β, IL-23, IL-6 and TGF-β.

Objective:This study was conducted to investigate the levels of IL-23 and IL-17 in sera and tumor tissues and to ana-lyze their association with clinico-pathological parameters in patients with colorectal cancer (CRC). Methods:A total of 24 healthy sub-jects and 56 patients with CRC were recruited in this study. Enzyme-linked immunosorbent assay was performed to measure the concen-trations of IL-23 and IL-17 in the sera of CRC patients and healthy controls and in cultured normal tissues and tumor tissues from CRC patients. Results:The levels of serum IL-23 and IL-17 were significantly higher in CRC patients than in healthy controls (P<0.01). The supernatant levels of IL-23 and IL-17 in tumor tissues were significantly higher than in normal tissues (P<0.05). Serum IL-17 level was correlated with tumor location, lymph node metastasis, and TNM stage (P<0.05), whereas serum IL-23 level showed no correlation with all clinico-pathological parameters (P>0.05). Tumor supernatant IL-17 level was correlated with tumor differentiation, lymph node metastasis, and TNM stage (P<0.05), whereas tumor supernatant IL-23 level was correlated only with TNM stage (P<0.05). Conclu-sion:IL-23 and IL-17 may be involved in the immuno-pathogenesis of CRC progression.