T helper 17 (Th17) and Th22 cells regulate the development of tumors. However, their roles in the development of colorectal cancer (CRC) are still unclear. A total of 49 patients with CRC and 18 healthy controls (HC) were evaluated for the percentages of circulating Th17 and Th22 cells by flow cytometry. The concentrations of serum interleukin-17A (IL-17A), IL-22 and carcinoembryonic antigen (CEA) were examined. The levels of IL-17A and IL-22 in tumors were determined by real-time PCR. We found that the percentages of Th17 and Th22 cells in the CRC patients were significantly lower than that in the HC and were associated negatively with the pathological stages of CRC. The levels of IL-17A and IL-22 mRNA transcripts were lower in the tumor tissues, particularly in the advanced CRC. After the tumor resection, the percentages of circulating Th17 and Th22 cells increased. These data suggest that decreased Th17 and Th22 responses may be associated with the development of CRC.
Keywords: Colorectal cancer; IL-17A; IL-22; Th17; Th22; peri-operative period.