在西方国家,食管腺癌(EAC)发病率逐年增加,且EAC与Barrett食管(BE)密切相关.近年来我国众多学者对BE和EAC发病情况进行了深入研究,但尚无文献对其进行总结分析.本文通过检索PubMed和中国医学文献数据库,分析了近年来有关我国BE和EAC研究的文章,探讨我国BE和EAC的发病情况和临床病理特点.检索词包括“Barrett食管”、“食管腺癌”、“中国人”和“中国”.通过分析发现,我国伴肠化生的BE检出率很低,一般人群为0.06％,有症状者检出率为1.8％.目前已确定我国BE的危险因素有老年和食管裂孔疝,其他可能的危险因素包括胃食管反流病、吸烟和酗酒.我国BE的发生与性别和肥胖无关.内镜下大多数柱状上皮食管和BE呈舌状或岛状,长度＜2 cm;我国长段BE非常罕见,尤其在女性人群中.近十年台湾和香港地区EAC的发病率很低,部分地区甚至有降低趋势.我国食管下段腺癌较少见,几乎所有胃食管连接(GEJ)处癌均以胃近端为中心生长.柱状上皮食管的临床意义及其是否存在恶变风险目前尚不清楚,需加大样本量进行更深入的研究.%Background: Development of multidrug resistance is a major deterrent in the effective treatment of cancers by chemotherapy. Emerging evidences suggest that epithelial-mesenchymal transition (EMI) mediated by zinc finger transcription factor Snail might contribute to chemoresistance in cancer cells. Aims: To investigate the effect of artificial microRNA-Snail (amiRNA-Snail) in reversing resistance of human gastric cancer cell line SGC7901/DDP to cisplatin (DDP) and its possible mechanism. Methods: SGC7901/DDP cell lines stably transfected with amiRNA-Snail plasmid (SGC7901/ DDP-amiRNA group) or negative control plasmid (SGC7901/DDP-Mock group) were constructed, respectively. Western blotting and immunofluorescence were used to determine the protein expressions of Snail, drug resistance gene ERCC1, and E-cadherin, the downstream target of Snail in transfected and untransfected cells. Survival rates of cells treated with DDP at different concentrations (0.01, 0.1, 1.0, and 10.0 mg/L) were assessed by CCK-8 assay and the 50% inhibiting concentration (IC50) of DDP was calculated. Results: Expression level of Snail protein in DDP-resistant SGC7901/DDP cells was significantly higher than that in DDP-sensitive parent SGC7901 cells (P<0.05). Expression levels of Snail and ERCC1 proteins were significantly decreased, and that of E-cadherin protein was significantly increased in SGC7901/DDP-amiRNA group than in SGC7901/DDP-Mock group (P<0.05), and the fluorescence intensities of these proteins were concordant with their expression levels. IC50 of DDP was significantly lower in SGC7901/DDP-amiRNA group than in SGC7901/DDP-Mock group (P<0.05). Conclusions: Silencing Snail gene by amiRNA-Snail may reverse resistance of human gastric cancer cell line SGC7901/DDP to DDP through down-regulating ERCC1 expression and up-regulating E-cadherin expression.
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