Study On KP Metabolic Disorder In Patients With Esophageal Cancer Through Ahrr-mediated Inflammation Caused By Smoking

Smoking is associated with the occurrence and development of tumors and cardiovascular diseases.Polycyclic aromatic hydrocarbons（PAHs）,the carcinogen in cigarette smoke,are the agonists of Aryl-hydrocarbon receptor（AHR）pathway.Among them,Aryl-hydrocarbon receptor repressor（AHRR）is one of the most sensitive genes for DNA methylation changes and gene expression changes caused by smoking.The expression of AHRR further aggravated the inflammatory response caused by smoking.Inflammation promotes the expression of Indoleamine 2,3-dioxygenase 1（IDO）,which is the key rate-limiting enzyme of Tryptophan（TRP）-Kynurenine pathway（KP）;changes TRP metabolism from 5-HT synthesis to KYN synthesis.The consumption of TRP and the level disorder of its downstream immunosuppressive metabolites are the key factors to promote tumor development and immunosuppression.Therefore,we propose a scientific hypothesis that PAHs in tobacco promote the inflammatory response of the body by acting on AHRR,and inflammation mediates the expression of IDO,which leads to the metabolic changes of TRP-KP.AHRR methylation sites and KP-related metabolites are expected to become biomarkers related to tumor prognosis.The main research contents are as follows.Firstly,methylation-driven genes were screened by analyzing DNA methylation data and gene expression data of esophageal cancer and adjacent tissues on the Cancer Genome Atlas（TCGA,https://www.cancer.gov/）,focusing on the correlation between esophageal cancer smokers and AHRR.The results of advanced functional analysis showed that the methylation-driven genes in esophageal cancer were mainly related to the metabolic dynamics of endogenous substances such as amino acids.The risk prediction model established by differential expression genes（P<0.001,AUC=0.791）was better than that established by differential methylation-driven genes（P=0.006,AUC=0.589）,and had better risk prediction ability.According to the gene AHRR closely related to DNA methylation caused by smoking,the analysis found that the methylation level of the site on AHRR was related to the clinical prognosis overall survival and long-term smoking accumulation（pack years smoked）.According to the susceptibility gene AHRR to DNA methylation changes caused by smoking,the analysis found that the methylation level of the site on AHRR was related to the overall survival（OS）and long-term smoking accumulation（pack years smoked）.In smokers,the four cg sites on AHRR were significantly correlated with the expression level of AHRR.Grouping the severity of smoking according to the total amount of smoking,it was found that the expression level of AHRR was higher in the severe group with more total smoking.It indicates that smoking promotes AHRR expression.The gene correlation analysis of AHR pathway,TRP metabolic pathway and inflammatory pathway among smokers with esophageal cancer suggests that there is a certain correlation and correlation among them.Then,the Ahrr^-/-C57BL/6 mouse model was established by CRISPR-Cas9 gene editing technology to explore the effect of AHRR differential expression on body function.The liver tissues of the control-experimental group mice were subjected to whole-gene transcriptome analysis to screen the differentially expressed genes.The results of advanced functional analysis of differentially expressed genes showed that the differential expression of AHRR in the body was related to abnormal glucose and lipid metabolism,which was mainly manifested as the down-regulation of the major urinary protein family genes.Associated with tumor formation,mainly for tumor suppressor gene up-regulation and proto-oncogene down-regulation.Moreover,it is related to the inflammatory response of the immune system,mainly manifested as the up-regulation of anti-inflammatory genes and pro-inflammatory genes and the enhancement of immune response.At the same time,extensive targeted metabolomics analysis of plasma metabolites found that pro-inflammatory metabolites such as Lysophosphatidylcholine（LPC）and arachidonic acid（AA）decreased significantly in vivo.The results of this analysis were highly consistent with the gene-disease association analysis results of AHRR conducted in Dis Ge NET database,another independent database.The above results showed that high expression of AHRR had a certain effect on promoting cancer and inflammation.Finally,393 participants with esophageal cancer were recruited to assess the difference in the metabolic level of TRP pathway metabolites in the plasma of smokers and non-smokers,and the correlation between TRP pathway metabolites and the progression stage of esophageal cancer.The results showed that smoking or not led to the differences in the metabolic levels of Kynurenine（KYN）,Xanthurenic acid（XA）and XA/KYN in the plasma of patients with esophageal cancer.They were all attributed to the downstream KP metabolic pathway of TRP metabolism.They had high exposure levels in smokers and were related to immunosuppression.Smoking can be used as an independent predictor of esophageal cancer progression.In summary,this study clarified the scientific problem of KP metabolic disorder in esophageal cancer patients caused by smoking through AHRR-mediated inflammation in three parts.At the same time,the correlation between AHRR cg site and TRP pathway metabolite levels and clinical endpoint events was found.This provides a new perspective for smoking to promote the occurrence and development of esophageal cancer,and has a certain reference value for tumor immune escape phenomenon and mining potential predictive biomarkers.It has important clinical value in the differential diagnosis and disease monitoring of tumors.In addition,the early warning of esophageal cancer with risk factor-smoking has important clinical significance for improving the treatment intervention time and low survival time of esophageal cancer.