The Interaction Of EGFR Mutation With Smoking And Other Factors And Correlation Between EGFR Mutation And Microrna-221 Expression In NSCLC

Objective:The aim of this study is to know the status of epidermal growth factor receptor(EGFR)mutations,detect the interaction of EGFR mutations with smoking and other factors as well as the correlation of EGFR mutation with clinical pathological characteristics in Non-small Cell Lung Cancer(NSCLC);To know the expression level of miR-221 in NSCLC and find out the correlation between miR-221 expression and EGFR gene mutations to provide clue and basis for studying the potential molecular mechanism of lung cancer.Methods:The clinical pathological characteristics and formalin fixed-paraffin embedded(FFPE)tissues of 78 NSCLC patients and 20lung benign lesion patients who underwent surgery in the one of hospital in Hengyang city from December 2013 to September 2016 were collected.We took the EGFR mutation as the case group and the wild type for the control group.DNA was extracted from FFPE tissues of 78 NSCLC patients and the interactions of smoking and other factors with EGFR gene mutation were detected by employing High Resolution Melting(HRM),direct PCR products sequencing and analyzed by logistic regression.The correlation between miR-221 expression detected by Real-time PCR and EGFR gene mutations was done by Spearman correlation analysis.Results:The prevalence of EGFR gene mutation in NSCLC is38.5%,and 19-del and L858R are the two main categories of EGFR gene mutation.Significant difference of EGFR gene mutation was observed between smoking and nonsmoking(χ~2=4.510,P=0.034).Nosignificant difference was observed between EGFR gene mutation and other factors and clinic pathologic parameters,including gender,age,histology,tumor size,p-TNM stage,degrees of pathological differentiation,lymphatic metastasis,family history of cancer and history of cardiovascular disease(P>0.05).There were no multiplicative interactions between EGFR gene mutation and smoking,drinking,family history of cancer,history of cardiovascular disease in lung cancer.The expression level of miR-221was significantly higher in NSCLC tissues than in lung benign lesion tissues by Rank sum test(Z=-2.392,P=0.017)and no correlation between the expression of miR-221 and EGFR gene mutation was found(r=-0.34,P=0.858).Conclusions:The prevalence of EGFR gene mutation in NSCLC is38.5%,19-del and L858R mutation were the two main mutational categories in NSCLC;No multiplicative interactions were observed between EGFR gene mutation and smoking,drinking,family history of cancer and history of cardiovascular disease in NSCLC;miR-221expression was up-regulated in NSCLC tumor tissues compared to the control untumor lung tissues;No correlation was observed between the expression of miR-221 and EGFR gene mutation in NSCLC.