The Effect Of Toll-like Receptor 4 On The Risk Of Different Digestive System Cancers And Regulation

Objectives To study the relationship between TLR4 gene and the risk of digestive tumor development and to preliminarily explore the regulation mechanism of TLR4 expression in esophageal cancer.Methods The effect of TLR4 expression levels on the risk of developing different digestive system tumors was evaluated using meta-analysis.The expression of TLR4 in different digestive system tumors and its relationship with the clinical progression of tumor patients were verified using GEPIA and UALCAN databases.TRANSFAC and Contra V3 softwares were used to predict transcription factors that might bind to the TLR4 promoter region.Mi RTar Base and starbase were used to predict the possible binding mi RNAs in the TLR43’UTR region and their expression differences in esophageal cancer and paracancerous tissues.Difference of TLR4 methylation in carcinoma and paracancerous tissues by Survival Meth was analyzed.Dual luciferase reporter assay and electrophoretic mobility shift assay were used to analyze the effect of rs1927914 genetic variation in TLR4 promoter region on transcription factor binding and transcriptional activity.Results Meta result showed that TLR4 expression levels in esophageal cancer(OR=9.11,95%CI=3.68～22.54,P<0.001),colorectal cancer(OR=4.34,95%CI=2.41～7.80,P<0.001),pancreatic cancer(OR=10.39,95%CI=4.99～21.65,P<0.001)and gastric cancer(OR=5.31,95%CI=1.66～16.93,P<0.001)were significantly higher than those in the corresponding paracancerous control tissues.The results of GEPIA and UALCAN analysis confirmed that TLR4 was overexpressed in esophageal cancer,gastric cancer,pancreatic cancer and rectal cancers(P<0.05),and the expression level of TLR4 was correlated with the clinicopathological stage of patients with gastric cancer,liver cancer and pancreatic cancer(P<0.05).TRANSFAC and Con Tra V3 predicted that the transcription factor Oct-1 was tightly bound to TLR4.The mi RTar Base analysis showed that hsa-let-7i-5p,hsa-mi R-146a-5p and hsa-mi R-181 b may bind to the TLR4 3’UTR region.Methylation analysis showed that TLR4 related methylation sites cg14605396 and cg14629571 had significantly lower methylation levels in esophageal cancer.Dual luciferase reporter gene and electrophoretic mobility shift assay confirmed that the rs1927914 genetic variation in the TLR4 promoter region affected the binding of the TLR4 promoter region to transcription factors and regulated gene transcriptional activity.Conclusions TLR4 expression was upregulated in esophageal cancer,gastric cancer,pancreatic cancer and rectal cancers.TLR4 may be regulated by transcription factor Oct-1,mi RNA(hsa-let-7i-5p,hsa-mi R-146a-5p,and hsa-mi R-181b)and methylation and affect the occurrence of esophageal cancer.The transcriptional activity of TLR4 can be affected by genetic variation in the TLR4 promoter region.Figure32;Table8;Reference 178...