PURPOSE To investigate the clinical value of the T-antigen monoclonal antibody method on screening of large intestinal carcinoma. METHODS The T-antigen monoclonal antibody method and the galactose oxidase method were simultaneously used to detect T-antigen in large intestinal mucus of 207 cases. RESULTS There was not obvious difference in screening value between the T-antigen monoclonal antibody method and the galactose oxidase method, for that they had similar sensitivity (69. 2%, 67. 3%) and specificity (64. 2%, 65. 6%) in diagnosis of large intestinal carcinoma. CONCLUSION The T-antigen monoclonal antibody method was convenient, eligible and valuable on screening of large intestinal carcinoma.

Objective To research the effect of the Kiss-1 gene promoter methylation on the Kiss-1 gene expression in colorectal carcinoma tissue,and to analyze the relationship between the Kiss-1 gene methylation and the clinical pathological features of colorectal carcinoma and its clinical significance.Methods The Kiss-1 gene promotor region methylation,Kiss-1 gene mRNA and protein expressions were detected respectively by methylation-specific PCR, Real-time PCR and Western blotting method in 126 cases of colorectal carcinoma tissue and para-cacinoma normal colorectal tissue.Results The positive rate of Kiss-1 gene methylation in colorectal carcinoma tissue (83.33%)was significantly higher than that in normal tissue (30.16%)(P<0.05).In the cancer tissue,the expression levels of Kiss-1 gene mRNA and protein in Kiss-1 gene promoter methylation positive group was lower than that in Kiss-1 gene promoter methylation negative group (P < 0.05 ). The positive rate of Kiss-1 gene promoter methylation in T3+T4 stage group was higher than that in T1+T2 stage group (P<0.05),but the Kiss-1 gene mRNA and protein expression levels were lower than those in T1+T2 stage group (P<0.05).In the poorly and moderately differentiated group,the positive rate of Kiss-1 gene promoter methylation was higher than that in well differentiated group (P<0.05 ), but the mRNA expression level of Kiss-1 gene was lower than that in well differentiated group (P<0.05 ). In lymph node metastasis group, the positive rate of Kiss-1 gene promoter methylation was higher than that in lymph node negative group (P<0.05),but the mRNA and protein expression levels were lower than those in lymph node negative group (P<0.05 ). And the positive rate of Kiss-1 gene promoter methylation in distant metastasis group was higher than that in non-distant metastasis group (P<0.05), but the mRNA and protein expressions levels were lower than those in non-distant metastasis group (P<0.05). There were no significant associations between the positive rate of Kiss-1 gene promoter methylation and the gender, age,tumor location, and tumor diameter of the patients (P>0.05 ). Conclusion The Kiss-1 gene promoter methylation in colorectal carcinoma tissue is associated with the Kiss-1 gene expression level and the malignant characteristics of colorectal carcinoma;Kiss-1 gene promoter methylation may be used as a reference indicator for predicting the risk of metastasis of colorectal carcinoma.

Objective:To explore the effects of KISS1 gene transfected by lentivirus on the proliferation,invasion and migration abilities of the colorectal cancer HCT116 cells,and to clarify their mechanisms.Methods:The human colorectal cancer cells with the lowest expression level of KISS1 gene were selected.The lentiviral vectors were builted and transfected the KISS1 gene,and the cells were divided into control group (treated with PBS),empty vector group (treated with empty vector) and over-expression group(treated with KISS1 gene vector).The multiplicity of infection (MOI) of the cells was detected by fluorescence microscope.Real-time PCR and Western blotting methods were used to detect the expression levels of KISS1 mRNA and protein(metastin);CCK-8 method was used to detect the proliferation ability of the cells;Transwell chambers method was used to detect the invasion and migration abilities of the cells.Results:Among LoVo,SW620,SW480,HCT-116,and HT29 cells,the expression levels of KISS1 mRNA and protein were lowest in HCT116 cells,so they were chosen as the research carrier.After transfected with lentiviral vectors,the HCT116 cells could stably express the enhanced green fluorescent protein(EGFP) gene,and the MOI was over 80%.Compared with control group and empty vector group,the expression levels of KISS1 mRNA and protein in the cells in over-expression group were significantly increased (P<0.05);the proliferation abilities of the cells in over-expression group were decreased (P<0.05);the invasion ability and migration ability of the cells in over-expression group were decreased (P<0.05).But the differences of proliferation ability,invasion ability and migration ability of the cells between control group and empty vector group were not statistically significant (P>0.05).Conclusion:The KISS1 gene transfected by lentivirus vector can over-express KISS1 protein and inhibit the proliferation,invasion and migration abilities of the colorectal cancer cells,and the mechanism may be related to the expression of KISS1 protein.