Research for esophageal carcinogenesis and differentiation induction therapy based on normal esophageal epithelial cells and esophageal stem cells

食道干细胞S1)人食道角质形成细胞干细胞表达低亲和力神经营养因子受体p75NTR，差异表达细胞黏附分子β-1和β-4整合素。根据角质形成细胞表面分子表达水平的不同，通过免疫细胞化学细胞分选的方法，可以将候选干细胞从角质形成细胞中分离出来作为次要细胞亚群。2)我们在体内证明了食道上皮细胞的分化，并在癌变的早期阶段检测到p75/NTR阳性的假定干细胞亚群中的初始遗传改变和异常细胞增殖，提示它们是致癌的初始靶细胞群。3)食道癌细胞系中含有不同水平的p75/NTR阳性细胞，这些细胞能比p75/阴性细胞产生更大的集落。P75/NTR阳性细胞通过siRNA显著抑制其生长。这些结果表明…进一步认为p75/NTR有可能成为食道癌干细胞的候选治疗靶点。胃十二指肠反流和吸烟对正常食道细胞的影响：1)胆汁酸联合胰酶和酸可显著上调正常食道细胞COX-2的表达和前列腺素E_2的生成。结果提示，十二指肠胃食道反流可诱导食道上皮细胞环氧合酶-2表达和前列腺素E_2的产生。环氧合酶-2特异性抑制物对食管癌可能具有化学预防作用。2)我们发现尼古丁通过上调从头甲基转移酶DNMT3A和FHIT蛋白的表达来诱导人食管鳞状上皮细胞FHIT甲基化。停止尼古丁暴露后，无法检测到FHIT甲基化。有趣的是，我们没有发现任何p16INK4a甲基化的证据。因此，FHIT可能对尼古丁治疗而不是对p16/INK4a敏感。我们的结果表明，持续吸烟可能会导致食道癌的风险。较少

Esophageal stem cell s1)Human esophageal keratinocyte stem cells are characterized by the expression of the low affinity neurotrophin receptor p75NTR and differentially expressed cell adhesion molecules, the β1 and β4 integrins. The candidate stem cells can be fractionated from keratinocytes as a minor cell subset by means of immunocytochemical cell sorting based on the different levels of expression of these cell surface molecules. 2)We demonstrated esophageal epithelial differentiation in vivo and detected an initial genetic alteration and abnormal cell proliferation in the p75/NTR positive putative stem cell compartment during the early stages of carcinogenesis, suggesting their role as an initial target cell population for carcinogenesis. 3)Esophageal cancer cells lines contained several levels of p75/NTR positive cells and these cells could reproduce larger colonies than p75/negative cells. p75/NTR positive cells dramatically suppressed their growth by SiRNA. These results suggest … More ed that p75/NTR may become a good therapeutic target and might be a candidate of cancer stem cell of esophageal cancer.Effect of gastroduodenal reflux and smoking on normal esophageal cell.1)COX-2 expression and prostaglandinE2 production were significantly up-regulated in normal human esophageal cells by bile acid in combination with trypsin and acid. The results suggest that duodenogastroesophageal reflux may induce cyclooxygenase-2 expression and prostaglandinE2 production in esophageal epithelial cells. Cyclooxygenase-2 specific inhibitors may have a chemopreventive effect on esophageal carcinoma. 2)We found that nicotine induced FHIT methylation via up-regulation of de novo methyltransferase Dnmt3a followed by loss of Fhit protein expression in human esophageal squamous epithelial cells. FHIT methylation was not able to be detected after cessation of nicotine exposure. Interestingly, we could not find any evidence of p16INK4a methylation. Thus, FHIT might be sensitive to nicotinic treatment rather than p16/INK4a. Our results suggest that continuous smoking may induce the risk of esophageal cancer. Less