The Expression Of AEG-1 And Its Related Microrna MIR-136 In Non Small Cell Lung Cancer And Its Clinical Significance

Background and ObjectiveLung cancer(LC) is the most common cancer in China and has the highest mortality in a variety of malignant tumors. LC is divided into small cell lung cancer and non-small cell lung cancer(NSCLC). NSCLC is further divided into adenocarcinoma(AC), squamous cell carcinoma(SCC) and large cell cancer (LCC). NSCLC accountes 75～80% of LC cases, and have a high degree of malignancy and poor prognosis. NSCLC is closely related to the malignant tumors regulatory molecules. Astrocyte elevated gene-1 (AEG-1) is found as a potential malignancy regulatory molecule in recent years. There are 9 papers about the relation between AEG-1 and NSCLC. However, the effects and mechanism of AEG-1 in NSCLC were not clear, yet. Malignant tumor is associated with microRNAs(miRNAs). Biological prediction software predict that the sequence of miR-136 is complementary with AEG-1, that means there is interaction between AEG-1 and mir-136. Therefore this study aimed to clarify the role and significance of AEG-1 and miR-136 in NSCLC and initially reveal the interation between AEG-1 and miR-136 by using tissue microarray technology, cell wax block, Western bolt(WB), scratch assay and colony formation assay, Transwell assay and tumor model assay and qRT-PCR.Methods1. Employed the tissue microarray to examine the level of the AEG-1 expression in 339 samples of NSCLC tissues,30 samples of adjacent non-cancerous tissues, and to analyze the relationship between AEG-1 and clinicopathological feature of NSCLC.2. To use cell wax block and WB to screen cell line with strongest expression of AEG-1 from lung cell lines as H460, H1299, A549, PC9, and to silence the expression of AEG-1 in lung cell lines by transfecting shRNA plasmid.3. To apply scratch assay, colony formation assay and Transwell to explore the invasion, proliferation and migration functions of AEG-1 in NSCLC.4. To construct chick embryo choriallantoic membrane model of NSCLC to clarify the biological role of AEG-1 in NSCLC.5. To use qRT-PCR to detect the expression of miR-136 in 65 cases of NSCLC tissue, and to predict the relationship of miR-136 and AEG-1.Results1. AEG-1 in NSCLC tissues were significantly up-regulated in tumor tissuses(p<0.05), its expression level were different based on the tumor size(p=0.000), TNM stage(p=0.003) and lymph node metastasis(p=0.000). Spearman index analysis indicated that the AEG-1 expression was positively correlated with tumor size(r=0.248,p=0.000) and TNM stage(r=0.182, p=0.001).2. They determined that invasion, proliferation and migration function of NSCLC cell line were inhibited by silencing expression of AEG-1 by scratch assay, colony formation assay and Transwell assay.3. The chick embryo choriallantoic membrane model of NSCLC indicated tumorigenic ability of NSCLC cell line was weaken by silencing AEG-1 expresstion.4. miR-136 in the NSCLC tissues were significantly down-regulated in tumor tissues (p=0.002), its expression level were different based on the TNM stage (p=0.001), lymph node metastasis (p=0.001). Spearman index analysis showed that the expression level of miR-136 was negatively correlatd with TNM stage (r=-0.376,p=0.002) and lymph node metastasis (r=-0.400, p=0.001).5. Partial sequences of AEG-1 was complementary to the miR-136, there was a negative correlation between them (r=-0.494,p=0.000).ConclusionThe occurrence and development, invasion, proliferation and migration function of NSCLC were positively related with the expression of AEG-1. Inhibition the expression of AEG-1 was expected to become a new method in the treatment of NSCLC, and AEG-1 may be a target for miR-136 in NSCLC.