The Expression And Clinical Significance Of IL-17 In Colorectal Carcinoma And The Interaction Of IL-17 And SW480 Cells

Part OneObjectivesTo explore the relationship between the expression of IL-17 and STAT3 in blood and tissue of CRC, and to investigate their possible relationships with the clinic pathological features and the angiogenesis.Methods1. Immunohistochemistry (SP method) was used to detect the expression of IL-17 and STAT3 proteins in 94 specimens of colorectal carcinoma tissues and 31 cases normal mucosa membrane. Microvessel density (MVD) was counted based on CD34 marked endothelial cells of nicrovessels.2. RT-PCR was used to detect the expression level of IL-17 mRNA in peripheral blood mononuclear cell (PBMC) of 7 colorectal carcinoma patients and 6 health people.3. ELISA was used to detect the expression level of IL-17 protein in plasma of 7 colorectal carcinoma patients and 6 health people.Results1. Immunohistochemical data showed that IL-17 protein significantly expressed in cytoplasm of tumor cells and stromal lymphocytes of CRC tissues. The positive expressions of IL-17 in tumor cells and stroma lymphocytes were significantly higher than in normal mucous membrane (P<0.01). The expression of IL-17 was related to cancer cell differentiation and Duke's stage (P<0.05). Compared with corresponding normal tissues, the levels of STAT3 were significantly increased in tumors of CRC patients (P<0.01). The expression of STAT3 in CRC was related to cancer cell differentiation, metastasis of lymphnode and Duke's stage (P<0.05). MVD was closely correlated to the expression of IL-17 and STAT3 (P<0.01). and there was a stable positive relationship among the two proteins (r=0.282,P=0.006). 2. The expression level of IL-17 mRNA in patients" PBMC was higher than control group (P<0.01).3. The expression level of IL-17 protein in patients' plasma was higher than control group (P<0.05).Conclusion1. The expression of IL-17 is up-regulated in stromal lymphocytes of CRC tissues, and the prevalence of intratumoral IL-17-producing cells correlate with the poorer differentiation and the higher Duke's stage. Moreover, the level of IL-17-producing cells are positively correlated the intratumoral MVD in tumor. It is suggested that IL-17 is derived from stromal lymphocytes in tumor. IL-17 may play an important role in the angiogenesis and metastasis of CRC.2. IL-17 and STAT3 expressing are significantly higher in CRC tissues, and MVD is closely correlated to these factors. It is suggested that the two factors may play an important synergism role in the angiogenesis and carcinogenesis of CRC.2. The expression level of IL-17 mRNA and protein are up-regulated in peripheral blood of CRC patients. It is implied that IL-17 is probably play an important regulation role involved in the pathogenesis of CRC.Part TwoObjectivesTo investigate the influence of human colon carcinoma cell line SW480 on IL-17 secreted by PBMC of healthy people in vitro and to examine the effect of recombinant human IL-17 (rhIL-17) on the proliferation, invasion and motility of SW480.Methods1. ELISA was used to detect the expression level of IL-17 protein in supernatants of PBMC cocultured with SW480 in vitro.2. Human colon carcinoma cell line SW480 cultured were treated respectively with different concentrations of rhIL-17. The effects of rhIL-17 on the proliferation property of SW480 were detected by MTT colorimetric assay.2. Boyden chamber were used to detect the effects of rhIL-17 with different concentrations on the invasion and motility of SW480.Results 1. IL-17 levels in supernatants from SW480 cocultures were higher than that of in medium alone and OKT3-preactivated PBMC (P<0.01).2. Human colon carcinoma cell line SW480 cultured in vitro were treated respectively with different concentrations of rhIL-17. The effects of rhlL-17 on the proliferation property of SW480 were detected by MTT colorimetric assay.3. Boyden chamber were used to detect the effects of rhIL-17 with different concentrations on the invasion and motility of SW480.Conclusion1. Tumor cells may facilitate the generation of IL-17 by PBMC.2. IL-17 may regulate the invasion and motility of the SW480 cells.