Expression And Regulative Relation Of KLF4 And VEGF In Colon Cancer

Colon cancer is a common malignant tumor which seriously threatens human beings,it’s incidence and mortality is increasing year by year both worldwide and in China.To explore the pathogenesis of the disease is of great significance in its diagnosis and treatment.KLF4(Gut enriched Krüppel like factor4),widely expressed in many human tissues and organs,with the regulation of cell proliferation,differentiation and apoptosis plays an important role in embryonic development and regulation.In addition,it is related to the development of many malignant tumors,become one of the most recent research focus of tumor related genes.According to the summary of the literature,KLF4 in gastric cancer,liver cancer,bladder cancer and skin cancer showed low expression,anti-cancer effect.It is highly expressed in primary breast ductal carcinoma,prostate cancer and oral squamous cell carcinoma,manifested as tumorpromotion.VEGF(vascular growth factor),as the most advanced angiogenic factor,has been found to be overexpressed in almost all solid tumors.It is considered to be the most powerful tumor growth promoting factor,and anti-VEGF drugs have been widely used in clinic.A large number of studies have confirmed that the expression of VEGF in colon cancer tissue and normal tissue has significant difference,moreover,with the depth of invasion and lymph node metastasis,it can be used as an indicator to predict the progression of colon cancer.However,there are few reports about the relationship between KLF4 and VEGF,especially in the pathogenesis of colon cancer,there is no report on whether there is an interaction between the two.This study was conducted to investigate the linear relationship between VEGF and KLF4 in colon cancer,detect the expression of VEGF protein in colon cancer cell line HT-29 after silencing the KLF4 gene.To reveal the pathogenesis of colon cancer andto explore a new therapeutic target for colon cancer.Objective:By detecting the expression of KLF4 and VEGF protein in cancer tissues and normal tissues,analysis of protein expression and its relationship,to confirm the relationship between KLF4 and the regulation of VEGF in colon cancer by detecting the expression of VEGF protein in colon cancer cell line HT-29 after silencing the KLF4 gene.Cultured colon cancer cell line HT-29 and down regulated the expression of KLF4 gene by transient transfection with KLF4-Si RNA,then cultivated silence expression in colon cancer cells.Methods:35 cases of colon cancer tissues and adjacent normal colon mucosa tissues were collected from Qinhuangdao First Hospital from September 2015 to January 2016.Detected the expression of KLF4 and VEGF protein by Western-blotting method,to react the expression of VEGF and KLF4 in colon cancer tissues and adjacent tissues.Used Western-blotting method to detect the expression of KLF4 and VEGF protein in the cells,and the transfection was proved to be successful.Then according to the changes of VEGF expression levels before and after transfection,the regulatory relationship between the two groups was determined,then statistical analysis was carried out of experimental data.Results:1 Colon cancer’s western-blotting results1.1 Expression of KLF4 and VEGF protein in colon cancer tissues and adjacent normal tissues:In colon cancer tissues,the expression of KLF4 is 0.403±0.072,which is significantly lower than that in the adjacent normal tissue of 0.613±0.206,the two results have significant difference in Statistics(t=-5.690,P<0.001).The expression of VEGF is 0.499±0.149,significantly higher than that in adjacent normal of 0.178±0.054,the two results have significant difference in Statistics(t=11.990,P<0.001).1.2 The relationship between the expression of KLF4 and VEGF protein in colon cancer tissuesAccording to the results of KLF4 and VEGF protein expression in Western-blotting,Pearson linear correlation analysis shows that KLF4 is negatively correlated with VEGF,r=-0.713(P<0.001).2 Western-blotting results of colon cancer HT-29 cell line after silencing KLF4 gene.2.1 Expression of KLF4 and VEGF protein before and after transfection of HT-29 cells:After KLF4 was silenced,extracted the total protein in colon cancer cell line HT-29 and detected the expression of KLF4 and VEGF content in two groups of cells by Western-blotting method:expression of KLF4 silencing of KLF4 protein in experiment group(KLF4/GAPDH)was 0.165 ± 0.017,significantly lower than the control group the expression of KLF4 protein was0.311±0.034,two results have significant difference(t=-11.470,P<0.001).The expression of VEGF(VEGF/GAPDH)KLF4 silencing experiment group is0.816±0.042,the control group is 0.630±0.083,two results have significant difference in Statistics(t=6.010,P<0.001).2.2 The relationship between the expression of KLF4 and VEGF protein in HT-29 cells after transfectedAccording to the results of KLF4 and VEGF protein expression in Western-blotting,Pearson linear correlation analysis shows that KLF4 is negatively correlated with VEGF,r=-0.764(P=0.016).Conclusion:1 In colon cancer,the expression of KLF4 protein was lower than that of adjacent normal tissues,it may be an inhibitory effect on the occurrence and development of colon cancer.VEGF protein expression in the tissues of colon cancer are significantly higher than in normal tissues adjacent to carcinoma.It is an promting factor in the development of colon cancer.2 KLF4-SiRNA transiently transfected HT-29 cells,the expression of KLF4 protein was down regulated,which indicated that transfection wassuccessful.3 The expression of KLF4 was decreased and the expression of VEGF was up-regulated after silencing KLF4,the regulatory role of the two may be related to the occurrence of colon cancer and tumor angiogenesis.KLF4 may influence the development of colon cancer by regulating the expression of VEGF protein.