| Chronic obstructive pulmonary disease (COPD) and lung cancer are two common lung disease. COPD is a disease characterized by persistent airflow limitation and ranking the third of the current death causes, lung cancer is one of the most common malignant tumor in the world with the fastest growing incidence and mortality, and thus a seriously threat to human health. A number of studies have shown that genetic factors also play an important role in these two lung diseases. Therefore, the research of pathogenic mechanism will shed more light on the prevention and treatment of COPD and lung cancer.In order to find the variation related to lung disease, a lot of genome-wdie association studies (GWAS) have been performed, which provided more insight into the onset of these two lung diseases. However, these are still a lot of issues remain unresolved. Firstly, GWAS has only found the genetic markers, rather than the real pathogenic locus. Moreover, GWAS can not determine the molecular mechanism by which genome variations affect disease susceptability.Recently, Allele-specific expression (ASE), as a special genetic phenomenon, has been a new way to scrutinize functional mutations. This method presents following advantages:(1) it can eliminate the influence of tissue physiological condition, and thus is accurate and sensitive; (2) the required sample size is low; (3) the detection method is simple, reliable, cheap and rapid; (4) the regulated target genes are clear; (5) it can greatly reduce the scope of functional sites, and improve the efficiency of research. Therefore, it was used by a number of researchers to identify functional mutation.Content and conclusions:this study collected the positive results of previous lung disease GWAS study and chooses 45 coding region mutations. By SnaPshot method, we found 8 SNPs present ASE, which indicated that these SNPs or the ones in LD with them can regualte the gene expression. The most significant ones are rs3751143 in P2RX7, rs1265093 in PSORS1C1, both of which are correlated with COPD, and rs1051730 in CHRNA3, which is associated with lung cancer. Through plasmid construction, mutationgenesis, luciferase assay,19 fundional mutations were identified. By use of chromatin immunoprecipitation and chromatin conformation capture method, we found that the rsl 15664826 and rs11615997 can alter POU2F1 transcription factor binding and, therefore, regulate PSORS1C1 and P2RX7 gene expression, respectively, which further influences COPD susceptibility.The significance of the study:this study can clarify the expression regulation mechanism of these lung disease related genes, and lays the foundation for the systematic understanding of the disease mechanism. Meanwhile, blocking the function of a key protein through small molecular compound, is a major way of cancer chemotherapy. Therefore, determining the related genes can provide a new target for cancer therapy and drug design. Secondly, the research can provide an example for gene expression regualation of other diseases and identification of human genome functional region by the comprehensive application of ASE and functional genomics. In addition, taking account of the pleiotropism, this study may also have a very important reference value for other diseases related with involved genes.The main problem has been solved:the genetic mechanisms of COPD and lung cancer.The innovation of this paper:the common GWAS-oriented functional genomics research is usually based on fine-mapping in huge population. This study is based on ASE in small cohort, which can quickly determine existance of the pathogenic mutations that can regulate gene expression and avoid the false positive in statistical methods. On the basis of this, we carried out a detailed functional genomic analysis, greatly saving the time, labor, and material resources. |
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