中文摘要：

在基因表达式规定和开发的 epigenetics 的角色显著地提高我们理解基因可以是 epigenetical 或基因 regulation.We 的目标肿瘤联系了的 carcinogenesis.All 的背景为在在胃的 cancer.The 的不同阶段的 DICER1 基因的表达式的数组分析和观察可变性瞄准的 cDNA 选择了一些 epigenetically 调整的基因这研究中是估计在 DICER1 的表达式之间的关联，一张 epigenetically 调整的情报

英文摘要：

Background The role of epigenetics in gene expression regulation and development significantly enhances our understanding of carcinogenesis. All the tumor related genes may be the target of epigenetical or genetic regulation. We selected some epigenetically regulated genes for cDNA array analysis and observed variability in the expression of the DICER1 gene in distinct stages of gastric cancer. The aim of this study was to assess the correlation between the expression of DICERI, an epigenetically regulated gene, and gastric cancer. Methods To detect the expression of 506 tumor-associated genes, including DICEFI1, in the matched cancerous mucosa, pre-malignant lesion （adjacent mucosa）, non-cancerous gastric mucosa and distant lymphocyte metastatic lesion in 3 cases of gastric cancers using cDNA array. DICER1 mRNA expression and DICER1 protein expression were further analyzed by Real-time PCR and Western blot in 32 cases of progressive gastric cancer. DICER1 protein expression was also detected in 33 early and 30 progressive gastric cancers by the immunohistochemistry （IHC） method. Results In 3 cases of gastric cancer cDNA array showed dramatically decreased expression of DICER1 in pre-malignant lesion, cancerous mucosa and distant lymphocyte metastatic lesions compared with matched noncancerous gastric mucosa, pre-malignant lesion and cancerous mucosa. Real-time PCR results showed that the expression level of DICER1 mRNA in gastric cancer was significantly down-regulated compared to normal gastric tissue （P〈0.05）. The IHC assay also showed that the expression of DICER1 was significantly decreased in progressive gastric cancer. Among the 63 cases of gastric cancers, 13/33 early （39.4%） and 19/30 （63.3%） progressive cancers showed negative expression of DICER1 （50.8%）. The difference in expression of DICER1 between early and progressive gastric cancers was significant （P〈0.01）. The result of Western blotting showed that DICER1 protein was down-regulated significantly in advanced gastr