Screening And Analysis Of Differential Expressed Genes In Lung Adenocarcinoma In XuanWei, China

ObjectiveLung cancer has the highest incidence and mortality rate among all types of cancers in the world, resulting in more annual deaths than breast, prostate and coloretal cancers combined. Because of non-specific clinical symptoms and lack of measures of detection early stage of lung cancer, most patients are diagnosed in late of lung cancer, that is, incurable stages and disappointing therapeutic regimens, resulting in poor prognosis. Adenocarcinoma is currently the predominant histological subtype of lung cancer, and over50%patients is adenocarcinoma. There are many complex influence factors, including enviromental pollution, genetic factor, carcinogen and so on. Notably, the incidence of lung cancer exceed the worldwide averge drastically in the XuanWei, China. The incidence of female is the most highest in the world. Thus, there is an urgent need to explore the initiation and development mechanism of the XuanWei lung cancer. Technologies that simultaneously analyse the expression of thousands of genes can be used to correlate gene-expression patterns. We used microarray-based gene expression techniques to screening differentially expressed genes between XuanWei lung adenocarcinoma and corresponding pericarcinomatous tissue and used bioinformation techniques to analyse differentially expressed genes, promising to find key genes related to the initiation, progression, invasion and metastasis of the disease. Meanwhile, it is to make a better understand the molecular mechaniasm undelying the XuanWei lung cancer tumorigenesis.Methods1. Specimens of XuanWei lung adenocarcinoma and corresponding pericarcinomatous tissue of operation resction came from department of pathology of Kunming Medical University First Hospital in2011March to2013December. All the datas were uniform nomenclature and classificated according to the revised scheme of the WHO pulmonary and pleural tumor histological type and reference to the surgical pathology diagnosis.2. The Whole Human Genome Microarray8×60K (Agilent) wer carried out on8fresh specimens. Fold change>2or <0.5are acceptible, then differentially expressed genes were obtained.3. After analying the DEGs by biomedical software and significant enrichment of GO terms between lung adenocarcinoma and corresponding pericarcinomatous tissue, aimiing at found key genes or pathways related to the disease, the molecular mechnisam underlying the XuanWei lung adenocarcinoma carcinogensis was established.4. Real time qPCR was applied to verify the expression of candidate DEGs at mRNA level, which identified by gene expression microarray in additional32fresh samples.Results1. Compared with the XuanWei lung adenocarcinoma and corresponding pericarcinomatous tissue, the greater changes in the number and expression levels of mRNAs, with a differential expression of6770mRNAs detected.2976genes were differentially expressed in6or more samples. Of these,1104genes were up-regulated and1872genes were down-regulated.2. GO analysis of DEGs suggested the involvement of wide-ranging cancer-related processes, including signal transduction, cell division, cell adhesion, regulation of cell proliferation and activation of MAPK activity. In addition, pathway analysis suggested that cell cycle, regulation of actin cytoskeleton, MAPK signaling pathway, P53signaling pathway, non-small cell lung cancer and Wnt signaling pathway were involved in.3.15candidate genes related to the disease were identified. PIK3R11、RARB、ZAK、 HGF、MAPK11and SESN1were down-regulated in lung adenocarcinoma tissue, and9genes, namely PAK1、E2F1、CCNE1、EGF、WHSC1、MXD3、CDC25A、PTTG1and UHRF1were up-regulated.4. There are no statistically different between microarry and qPCR in32samples of15candidate genes.Further analysis showed no-significant correlation between15genes expression level and clinicopatholigial features such as age, gender, clinical stage or lymph node metastasis. But2genes expression level, PAK1and HGF, were significantly correlation with histological differentiation(P PAK1=0.031, P HGF=0.045). The expression level of2genes are higher in moderately to well differentiation. Moreover, another2genes expression level, RARB and MAPK11, were significantly correlation with smoking status. These expression level are lower in smoking patients than never-smoking patients.Conclusions1. Differentially expressed genes of XuanWei lung adenocarcinoma can be rapidly detected by highrought platform microarray-based gene expression profiling. These genes involved in huge changes of lung adenocarcinoma and corresponding pericarcinomatous tissue at transcriptional level, suggesting that further study on the selecion of distinct genes would make us better understand the molecular mechanism of carcinogensis of XuanWei lung adenocarcinoma.2. Afer screening by gene expression microarray,15candidate genes were verified by real time qPCR. DEGs active MAPK signaling pathway, then further affect cell division, differentiation or adhesion. The expression level of PAK1, HGF and RARB, MAPK11were significantly correlation with histological differentiation and smoking status respectively. Overview,4DEGs in XuanWei lung adenocarcinoma would give us some new clues and thoughts for further revealing the pathogenesis of disease.