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Lung cancer is the highest morbidity and mortality worldwide, the treatment effect is relatively poor cancer. Lung cancer is a serious hazard to human health, has become the first cause of cancer death. Symptoms first treatment in lung cancer patients, more than 80% because of the transfer or there are contraindications lose the chance of operation. The overall 5-year survival rate of lung cancer is 15%, less than 10% in our country. 5-year survival rate of lung cancer: IA 67%, IB 57%, II A 34%, the Ⅱ B 24%, Ⅲ B 6% to 8% of IV 3%. Therefore, early diagnosis of lung cancer is of great significance to improve the 5-year survival rate. DNA methylation as part of the epigenetic regulation of gene expression. Has been found that many gene promoter region methylation abnormalities associated with cancer, such as cell cycle genes, DNA repair genes, angiogenesis genes, apoptosis related genes, cell adhesion migration related genes, hormone receptor gene. Thus, methylation is becoming a new class of biomarkers, to become effective diagnosis of the tumor marker molecule, is also becoming a promising target candidate for tumor therapy. Experimental studies have shown that demethylation treatment, you can make because of the unusually high methylation and expression silencing of p16 to control cell proliferation, differentiation, and apoptosis gene restored expression, which may inhibit tumor cell growth, increased cell adhesion and restore sensitivity of chemotherapy drugs to achieve the purpose of treatment of the tumor. This project intends to lung cancer by detecting gene promoter methylation analysis of promoter methylation and gene expression in lung cancer cell growth, differentiation, proliferation and apoptosis in detection of lung cancer-related genes in human peripheral blood specimens promoter The methylation frequency to explore the relationship between gene methylation and lung cancer, evaluation methylation mark as early diagnosis of lung cancer and as therapeutic targets feasibility. The topics selected NDRG2 P16, CDH1 RARbeta2 and WIF-1 five candidate tumor suppressor gene, training A549, GLC-82 two kinds of lung cancer cells, ECV-304 GES-1 two non-tumor cells as a control, from the cells extraction of genomic DNA, after bisulfite treatment, to use PYRO ASSAY Design Design PCR primers for amplification of a target gene promoter region, then the extent of gene methylation analysis using pyrosequencing technology. Found five genes NDRG2, P16, RARbeta2 gene methylation frequency in the group of lung cancer cells and non-tumor cells between groups were significantly different in the four cells have different degree of methylation phenomena CDH1 WIF -1 both genes was no significant difference. To explore the relationship between the gene promoter methylation status of the gene expression of the sub-region, methylation inhibitor 5 - aza-2 - deoxycytidine (5-Aza-2-CdR) for both lung cancer cells different concentration and time of treatment, found that treatment NDRG2, P16, RARbeta2 three genes to restore expression, suggesting that these three genes in lung adenocarcinoma cell silencing and promoter hypermethylation relevant. Currently, most of methylated genes associated with cancer of the studies are based on clinical biopsy rarely based on methylation analysis of body fluids (plasma / serum, sputum, urine, ascites, etc.). In this study, the genomic DNA was extracted from peripheral blood of lung cancer patients and normal five gene promoter region methylation levels were analyzed NDRG2, P16, CDH1 three frequency of methylation of the gene in lung cancer group than the normal group and statistically significant, consistent with the results in the literature. WIF-1 gene methylation frequency of lung cancer group, although slightly higher than the normal group, there is no significant difference between the two groups, do not rule out a small amount of samples tested, testing sites are not specific and different methods to measure the deviation.
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