Upregulation of Treg-Related Genes in Addition with IL6 Showed the Significant Role for the Distant Metastasis in Colorectal Cancer.

Abstract

T helper 17 (Th17) and T regulatory (Treg) cytokines appear to be contributing greatly to colorectal cancer (CRC) development and progression. The aim of the current study was to investigate the expression of Foxp3; IL10; TGFB1; IL17A; IL6 and NOS2 genes in tumor tissue, regional positive lymph nodes and distant metastasis obtained from 26 patients with advanced CRC. Quantitative real-time polymerase chain reaction (qPCR) was performed for mRNA detection by TaqMan gene expression assay. In distant metastasis, IL6 was strongly expressed, over 7.5 fold, followed by Treg-related genes Foxp3; IL10 and TGFB1 in contrast to IL17A and NOS2. The similar pattern of expression was observed in positive regional lymph node in addition to significant down-regulation of NOS2 (RQ=0.287; p=0.011) and a trend for the elevation of IL17A. In tumor tissue, Fopx3 was significantly upregulated and Foxp3 mRNA positively correlated with TGFB1 in all investigated tissue types. In tumor tissue, expression of IL17A was correlated with NOS2 (r=0.68; p=0.005), while in distant metastasis IL10 was in strong relation with TGFB1 and IL6. In addition, a reverse correlation between IL6 and NOS2 (r=-0.66; p=0.009), was observed in distant metastasis. The simultaneous expression of given Treg and Th17-related genes found both in the primary tumor and in the regional lymph nodes appears to provide suitable microenvironment sufficient for promoting metastatic growth. The upregulation of Foxp3; IL10, TGFB1 and IL6 might be a transcriptional profile hallmark for colorectal metastases.