The Epidemiological Study On The Association Of Single Nucleotide Polymorphisms Within MicroRNA Binding Sites In NF-κB And STAT3Inflammatory Signaling Pathways And Environmental Factors With The Risk Of Lung Cancer

[Objective]To investigate the independent and combined effects of the environmental riskfactors and gene polymorphisms within microRNA binding sites in NF-κB and STAT3inflammatory signaling pathways to the development of main pathological types oflung cancer. To explore the expression of miR-181b in the main pathological types oflung cancer cells, including adenocarcinoma, squamous cell carcinoma and small celllung cancer, and its potential function of epigenetic regulation in gene expression.[Methods]1. A case-control study was conducted with1312patients and1556controlsubjects. Patients were recruited from the First affiliated hospital and the affiliatedUnion Hospital of Fujian Medical University and Fuzhou General Hospital withbronchoscopy and pathologic confirmation. All healthy controls were enrolled fromhospital visitors and community population, and were frequency-matched to the caseson age(±2year) and gender. Eligible subjects were personally interviewed using aquestionnaire. Univariate and multivariate unconditional logistic regression, crossoveranalysis and classification trees were used to identify the risk factors and combinedeffects of lung cancer and estimate the odd ratios (ORs) and95%confidenceintervals (95%CIs).2.5ml blood sample was collected from each patients. The collection of samplesamong control subjects was accomplished by using OrageneTMDNA self-collectionkit. The genomic DNA was extracted from all blood and saliva samples. Thegenotypes of polymorphisms were determined by SNaPshot platform. Univariate andmultivariate unconditional logistic regression, crossover analysis were used to identifythe independent and combined effects of gene polymorphisms within microRNA binding sites in NF-κB and STAT3inflammatory signaling pathways andenvironmental factors to the development of lung cancer.3. Detect the expression of miR-181b in normal human bronchial epithelialcells(16HBE), lung adenocarcinoma cells(A549), lung squamous carcinomacells(SK-MES-1) and small cell lung cancer cells(H446), and speculate its potentialfunction of epigenetic regulation in gene expression.[Results]1. The risk factors of lung cancer included: BMI<18.5, polluted factories near theliving place, insufficient ventilation at home, cooking oil fumes, smoking, passivesmoking (at home and workplace), history of lung disease, history of pulmonaryoperation, family history of lung cancer, introversive character. The protective factorsof lung cancer included: BMI≥24, frequent intake of kelp(1-4times/month), frequentintake of fruits, light tea drinking, and frequent exercise. Among them, with theincrease of fruit intake frequency, the risk of lung cancer is reducing. In general, thereare some differences among the risk factors of different pathological types of lungcancer.2. The IL1R1rs3732133TT genotype significantly reduced the risk of lungsquamous cell carcinoma, while the IL6R rs4072391TT genotype obviouslyincreased the risk of lung squamous cell carcinoma, the STAT3rs3744483CTgenotype and the STAT3rs1053023CT genotype were observed associated withhigher risk of small cell lung cancer. No association between the SNP of IKBKErs10836, NFKBIA rs2273650, RELB rs28372683, IL1R1rs3732131and thesusceptibility of lung cancer was observed.3. The analysis of combined effects and interactions showed that, there was anegative interaction between smoking pack-years＞29and fruit intake1-3times perweek, while a positive interaction between passive smoking and kelp intake1-4permonth was observed. Positive additive interactions were observed between smokingand residence polluted factories, infrequent intake of fruits, infrequent intake of kelp,besides，negative additive interactions between passive smoking and infrequent intakeof fruits, infrequent intake of kelp were observed. In addition, the carriers with both IL1R1rs3732133and IL6R rs4072391adverse genotype were confronted with asignificant increase risk of lung cancer, particularly lung squamous cell carcinoma,while persons who carried IL6R rs4072391and STAT3rs3744483, rs1053023adversegenotype encountered significantly increased risk of small cell lung cancer. Nointeraction between environmental factors and genetic polymorphism was found.4. The expression of miR-181b in three different pathological types of lung cancercell lines were higher than normal human bronchial epithelial cells. Among them，thehighest expression level of miR-181b was observed in lung squamous carcinoma cells,followed by small cell lung cancer cell line and lung adenocarcinoma cell line.[Conclusion]1. Different environmental and genetic risk factors among different pathologicaltypes of lung cancer were observed.2. The combined effects and interactions between risk factors of lung cancer cannot be ignored. Heavy smokers and passive smokers can increase the intake frequencyof fruit and kelp and reduce the chance of contacting living environmental pollutionfactors to decrease the risk of lung cancer. In addition, the carriers with adverse allelesshould strengthen the prevention and control of lung cancer early.3. The high expression of miR-181b in lung cancer cell lines might be related tothe mechanism of lung cancer development. MiR-181b may alter the risk of lungcancer through regulating the IL6R gene that containing rs4072391allelic variantdifferently, further experimental studies are needed to confirm.