目的 研究缺氧诱导因子-1α（HIF-1α）与基质金属蛋白酶-2（MMP-2）在低分化胃癌中的表达，并探讨两者在低分化胃癌浸润、转移过程中的相互关系及作用。方法 采用SP免疫组化方法，检测54例低分化胃癌及20例正常胃组织石蜡标本中HIF-1α和MMP-2蛋白表达水平。结果 低分化胃癌组织中HIF-1α和MMP-2蛋白表达阳性率明显高于正常胃组织（Plt;0.05）。两者的表达与肿瘤的浸润深度、淋巴转移和TNM分期均有关（Plt;0.05），HIF-1α与MMP-2的表达呈正相关（r=0.580, Plt;0.05）。结论 HIF-1α和MMP-2在低分化胃癌的侵袭、转移过程中存在一定的协同作用，两者可能成为判断胃癌预后的指标。
Objective To investigate the role of DNA methylation on regulation of cell apoptosis and proliferation in ischemia-reperfusion of small intestine. Methods Thirty-five male Wistar rats were randomly divided into normal group， sham operation group， and ischemia-reperfusion group. The apoptotic cell was assessed by TUNEL and electron microscopy and the expression of Ki-67 was examined by immunohistochemistry in the small intestinal parts （villi epithe-lium， crypt epithelium， and lamina propria mucosa of small intestine）. The DNA methylation was detected by DNA histo-endonuclease-linked detection of methylated DNA sites. Results ①The apoptotic positive cells increased at 3 h， 6 h，and 12 h after ischemia-reperfusion in the villi epithelium， crypt epithelium， and lamina propria mucosa of small intestine as compared with the normal group and sham operation group （P＜0.01）；Moreover， the apoptotic cells in the lamina propria mucosa of small intestine were identified as T cells by electron microscopy. ②The expressions of Ki-67 markedly increased at 3 h， 6 h， 12 h， and 24 h after ischemia-reperfusion in the villi epithelium cells as compared with the normal group and sham operation group （P＜0.01）. ③The weak expression of DNA methylation was found in the villi epith-elium and crypt epithelium in the normal group and sham operation group， the b expression was examined in the crypt epithelium cells nearby stem cell site in the ischemia-reperfusion of small intestine， the change of expression was gradually weak from crypt epithelium to villi epithelium. Conclusion This initial results indicate that the DNA methyl-ation in the ischemia-reperfusion of small intestine might regulate cell apoptosis and proliferation.