Study On Characteristics Of Respiratory Microbiome Of Xuanwei Lung Cancer And The Tumorigenesis Of Benzopyrene

The increasing incidence and high mortality of lung cancer have brought heavy burden and challenge to patients and health care.The pathogenesis of lung cancer is very complex and affected by many factors.In addition to genetic susceptibility and environmental factors,some studies have revealed a close relationship between imbalance in respiratory microbiome and lung cancer.Meanwhile,the respiratory microbiota is affected by individual environmental exposure,and different environmental and disease factors,leading to different changes in the respiratory microbiome,which may has a different relationship with lung cancer.Xuanwei,Yunnan Province,has one of the highest rates of lung cancer morbidity and mortality in China and the world,which has been attributed to high indoor coal smoke exposure.This area is the Late Permian coal accumulation area in eastern Yunnan and western Guizhou.Smoky coal combustion generates substantial carcinogenic polycyclic aromatic hydrocarbons(PAHs)which is easy to be absorbed by the body and carcinogenesis.Furthermore,Xuanwei City has twice the national average prevalence rates of COPD in China,which is likely to be related to coal smoke exposure and imbalance of respiratory microbiota.Meanwhile,the presence of COPD has been proved to be an independent risk factor for lung cancer.The characteristics of respiratory microbiota of lung cancer patients with high coal smoke exposure in Xuanwei area are unclear,and its relationship with smoking,coal smoke exposure and disease factors(COPD)remain to be explored.In addition,benzopyrene,as a major carcinogenic polycyclic aromatic hydrocarbon from the combustion of smoky coal in Xuanwei,is associated with the development of lung cancer,and can induce A/J mice lung adenoma and adenocarcinoma.As a common lung tumor model induced by carcinogen exposure,A/J mice can be used to explore the mechanism of the interaction between respiratory microbiota and host in the development of lung tumors induced by carcinogen exposure.In this study,we analyzed the structure and characteristics of respiratory microbime of 44 patients with non-small cell lung cancer(NSCLC)and 45 healthy controls exposed to coal smoke using 16 S sequencing technology,and explored the influence of the pathological classification of lung cancer,smoking,coal smoke exposure and COPD on respiratory microbime.Subsequently,in the mouse model of lung adenoma induced by benzopyrene,the dynamic changes of the respiratory tract mocrobiota,and the correlation between microbe and the gene expression of lung tissue,airway metabolites,and blood index of host were analyzed to explore the interaction between respiratory microbiota and host.The main findings are as follows:(1)Beta diversity of respiratory microbiota is significantly different(Brary Curits distance)between patients with NSCLC and healthy controls in Xuanwei(P < 0.01).The composition of respiratory microbiota is also different between the two groups,including 48 species,47 genera,24 families,10 orders,2 classes,and 1 phylum(P < 0.05).Three genera were obtained using LEf Se analysis: Neisseria,Veillonella and Pseudomonas,among which Neisseria and Veillonella are significantly decreased in lung cancer patients(P < 0.001),and Pseudomonas increased(P < 0.001).In addition,lung cancer group has increased relative abundance of facultative anaerobe and decreased aerobe(P < 0.05).There are differences in respiratory microbiota between patients with squamous cell carcinoma and adenocarcinoma.(2)Smoking and coal smoke exposure have effects on respiratory microbiome.In healthy controls,coal smoke exposure is inversely associated with the relative abundance of the Actinobacteria,Actinomyces(P < 0.05),and positively correlated with Proteobacteria,Neisseria(P < 0.05).Pack-year of smoking is negatively correlated with Proteobacteria and Neisseria,and positively correlated with Actinomyces(P < 0.05).Smokers have lower abundance of Epsilonbacteraeota and Campylobacter(P < 0.05).In addition,coal smoke exposure is positively correlated with Gram negative,Stress tolerant Contains and mobile elements,while negatively correlated with Gram positive(P < 0.05).There is a positive and negative correlation between pack-year of smoking and Gram-positive and Gram-negative,respectively(P < 0.05).No the same correlation was find in lung cancer group.(3)Compared with healthy control or lung cancer groups,patients with COPD exposed to coal smoke exposure have a higher alpha diversity index.The relative abundances of 6 families and 5 genera show a gradually increasing trend from healthy controls to COPD to lung cancer.(4)In the mouse model of lung adenoma induced by benzopyrene,increased expression levels of inflammation factor(IL-1?,IL-6),decreased expression levels of epithelial barrier molecular(ZO-1,Occludin,E-cadherin)and tumor suppressor genes(P16,Rassf1)were observed(P < 0.05).(5)In the mouse model of lung adenoma induced by benzopyrene,respiratory microbiome shows dynamic changes.There is a correlation between the respiratory microbiome and the expression level of specific genes in lung tissue.The expression of inflammatory factor genes(IL-1?,IL-6,IL-17A)is negatively correlated with the abundance of Bacteroidaceae,and Corynebacteriaceae,and IL-1? is negatively correlated with the abundance of Bacteroides and Kocuria(P < 0.05).The abundances of Corynebacteriaceae,Bacteroidaceae,Bacteroides,Kocuria are decreased in Bap group.The negative correlation between these different bacteria and the gene expression of inflammatory factors may aggravate the inflammatory response and further lead to the imbalance of microbiome and disease progression.(6)In the mouse model,the respiratory metabolites are significantly altered,and Corynebacterium is positively correlated with 3-indoleacrylic acid and Corticosterone,while Brevundimonas is negatively correlated with Nicotine.In this study,the characteristics of respiratory microbiome of non-small cell lung cancer exposed to soot in Xuanwei,and the relationship of respiratory microbiome to smoking,coal smoke exposure,and COPD were analyzed.In the animal model of lung tumor induced by benzopyrene,the interaction between respiratory microbita and host(tissue gene expression and metabolites)may further aggravate disease progression and bacterial disturbance.This study can provide clues and theoretical reference for subsequent studies on the relationship between respiratory microbiome and lung tumor.