胃癌中钙黏附分子启动子甲基化与幽门螺杆菌感染及肿瘤生物学特性的关系

目的建立甲基化特异性聚合酶链式反应方法检测组织中钙黏附分子（CDH1）的甲基化程度;探索CDH1启动子的甲基化与幽门螺杆菌（HP）感染及与肿瘤分化、浸润、淋巴及远处转移之间的关系。方法采用热转化甲基化特异性聚合酶链式反应法检测2008年1月-2009年12月共40例胃癌手术标本中CDH1的启动子甲基化情况,并回顾性地分析CDH1的启动子甲基化与HP感染、肿瘤分化、浸润、淋巴及远处转移等肿瘤生物学特性的统计学关联。结果胃癌组CDH1基因甲基化阳性率高于对照组（67．5％、12．5％,P〈0．05）。胃癌组中低一未分化肿瘤组CDH1基因甲基化阳性率高于高．中分化肿瘤组（80．6％、22．2％,P〈0．05）;胃癌组中HP阳性患者的CDH1基因甲基化率高于HP阴性患者（78．1％、25．0％,P〈0．05）;而胃癌组中CDH1基因甲基化阳性率与患者性别、肿瘤浸润程度、淋巴转移及远处转移无明显关系（P〉0．05）。结论CDH1基因甲基化可能参与了胃癌的发展过程,并且CDH1基因甲基化可能导致了肿瘤分化程度的降低。CDH1基因甲基化与胃癌患者的HP感染之间可能存在密切关系,提示HP感染可能参与了抑癌基因甲基化失活及肿瘤演变的发展过程。     

甲乙煎影响H_(22)小鼠肝癌组织黏附分子E-cadherin表达的实验研究

目的:探讨甲乙煎对肝癌组织中细胞黏附分子E-cadherin表达的影响.方法:复制H22小鼠肝癌淋巴道转移模型,用中药甲乙煎水煎液(大、中、小剂量)、生理盐水灌胃和5-Fu腹腔注射20天,计算脾指数、胸腺指数,通过免疫组化法观察局部瘤组织中细胞黏附分子E-cadherin的表达水平.结果:中药大、中、小剂量组的脾指数、胸腺指数均高于生理盐水和5-Fu组,中药大、中、小剂量组和5-Fu组E-cadherin表达均高于生理盐水组.结论:甲乙煎可改善小鼠的免疫功能,提高H22小鼠肝癌局部瘤组织中细胞黏附分子E-钙黏蛋白的表达水平.     

E-cadherin基因在卵巢癌高低转移细胞中的差异表达及其机制的探讨

[目的]探讨上皮性细胞黏附分子在人卵巢浆液性囊腺癌高、低转移细胞株HO-8910和HO-8910PM的表达情况.[方法]采用蛋白印迹及免疫细胞化学方法检测2种细胞株的E-cadherin蛋白表达差异,用RT-PCR法检测2种细胞株的mRNA表达差异,用PCR及基因测序法检测基因突变情况.[结果]E-cad蛋白及mRNA在HO-8910中表达,在HO-8910PM中不表达.在E-cadherin基因外显子6～9未发现突变.[结论]E-cad的表达可能与肿瘤的转移能力负相关.     

转录抑制因子Snail表达与胃癌Lauren分型的关系研究

目的探讨转录抑制因子Snail表达与胃癌Lauren分型的关系。方法Western印迹检测肠型胃癌细胞系（N87）和弥漫型胃癌细胞系（AGS）中Snail和上皮型E钙黏蛋白（E-cadherin）的表达。将糖原合酶激酶．3B（GSK-3B）质粒转染胃癌细胞系,检测Snail和E-cadherin的表达变化。收集2000年2月至2005年12月间在复旦大学附属中山医院行胃癌根治术的77例术后组织标本．采用免疫组织化学染色检测Snail在胃癌组织中表达．并分析其与胃癌Lauren分型之间的关系。结果Snail在N87中低表达,在AGS中高表达;E-cadherin表达与Snail相反。转染GSK-3B后,胃癌细胞Snail表达显著下调,E-cadherin表达显著上调（P〈0．01）。使用不同浓度的GSK-3B抑制剂氯化锂处理后．胃癌细胞Snail表达显著上调,且具有明显浓度依赖性（P〈0．01）。21例肠型胃癌中Snail低表达16例,高表达5例;56例弥漫型胃癌中Snail低表达21例,高表达35例;肠型胃癌中Snail表达明显弱于弥漫型,差异有统计学意义（P〈0．01）。结论Snail的表达与胃癌Lauren分型有关．是一种潜在的确定胃癌分型的分子标志物。     

Loss of claudin-1 expression correlates with malignancy of hepatocellular carcinoma

BACKGROUND: The prognosis for the hepatocellular carcinoma (HCC) patient is affected by invasion and metastases. The attenuated expression of adherens junction protein epithelial-cadherin (E-cad) correlates with a more malignant potential in HCC. However, the potential of the claudin (CL) family of tight junctional proteins for HCC prognosis has remained unrecognized. MATERIALS AND METHODS: We immunohistochemically examined the expression of CL-1 and E-cad in resected specimens from 55 HCC cases. The percentage of CL-1- or E-cad-positive cells was counted in HCC cells and the surrounding hepatocytes and scored as 0 (0%), 1 (1-33%), 2 (34-66%), and 3 (67-100%). The expression of CL-1 or E-cad was considered "preserved" if the score in HCC was equal to or more than that in the surrounding hepatocytes, and "attenuated" if not so. RESULTS: In nontumorous tissue, CL-1 and E-cad were observed at the lateral surface of hepatocytes and biliary epithelial cells. In well-differentiated HCCs, the expression of CL-1 and E-cad was preserved in 12 of 14 cases. In poorly differentiated HCCs, E-cad expression was preserved in 9 of 18 cases, while CL-1 expression was preserved in only 4 cases (P<0.01 versus well-differentiated HCCs). HCCs with portal invasion showed significantly attenuated CL-1 expression than those without portal invasion (P<0.05). The survival rate after hepatectomy for HCC with attenuated CL-1 expression was significantly lower than that for HCC with preserved CL-1 expression. CONCLUSIONS: Attenuated expression of CL-1 closely correlates with the dedifferentiation and portal invasion of HCC. Down-regulated CL-1 expression may serve as a potential marker for a poor prognosis in HCC.     

上皮钙黏素1基因启动子甲基化对结肠癌上皮钙黏素和β-连接素表达的影响

目的 探讨上皮钙黏素基因(CDH1)启动子甲基化与结肠癌上皮钙黏素(E-cadherin)及β-连接素(β-catenin)的表达及临床病理特征的关系.方法 采用甲基化特异性PCR技术检测68例结肠腺癌组织、癌旁组织及正常黏膜组织中CDH1基因启动子甲基化的状况.采用免疫组织化学法检测E-cadherin及β-catenin蛋白的表达.结果 癌旁组织及癌组织中CDH1启动子甲基化的阳性表达分别为32.4%(22/68)、57.4%(39/68),正常组织均为阴性表达(P<0.05).E-cadherin在正常组织、癌旁组织及腺癌组织中阳性表达率分别为92.6%、66.2%和44.1%.正常组织中β-catenin均表达于细胞膜上,无胞质和(或)胞核表达,而β-catenin在癌旁组织及癌组织中胞质和(或)胞核表达分别为29.4%和50.0%.CDH1基因启动子甲基化阳性率与E-cadherin表达则呈负相关(r=-0.312,P=0.01),与β-catenin胞质和(或)胞核表达呈正相关(r=0.309,P=0.018).CDH1基因启动子甲基化及E-cadherin、β-catenin的异常表达均与结肠癌分化程度及转移密切相关(P<0.05).结论 CDH1基因启动子甲基化可能是导致结肠癌E-cadherin与β-catenin异常表达及肿瘤侵袭性增强的重要原因.

Abstract：

Objective To investigate the relationship between methylation of the CDH1 gene promoter on the expression of E-cadherin and β-catenin, and to evaluate the correlation with clinicopathological characteristics of the colonic carcinoma. Methods Methylation specific PCR (MSP) was used to detect CDH1 gene promoter methylation in the cancer tissue, adjacent tissues and normal tissues in 68 patients. The expression of E-cadherin and β-catenin was determined by immunohistochemistry staining. Results The positive rate of CDH1 gene promoter methylation was 32.4% in adjacent tissues and 57.4% in cancer tissue, while no detectable methylation was found in all the normal tissues. The difference was statistically significant. The positive rate of E-cadherin was 92.6% in the normal tissues, 66.2% in the adjacent tissues and 44.1% in the cancer tissues. In all normal tissues, β-catenin was expressed only at the cellular membrane but not in the cytosol or nucleus, while the expression of β-catenin was present in the cytosol or nucleus in 29.4% of the adjacent tissues and 50.0% of the cancer tissues. The positive rate of CDH1 gene promoter methylation was negatively correlated with E-cadherin expression (r =-0.312,P =0.01) and positively correlated with β-catenin cytosolic/nucleus expression(r=0.309,P=0.018). The differentiation and metastasis of colonic carcinoma were associated with the aberrant expression of E-cadherin, β-catenin, and methylation of CDH1 promoter (P<0.05). Conclusion CDH1 gene promoter methylation may lead to aberrant expression of E-cadherin and β-catenin in colonic carcinoma, and may play an important role in promoting the invasion of tumor.     

结直肠癌组织中Ezrin和E-cadherin蛋白的表达特点及意义

目的:探讨结直肠癌组织中Ezrin和钙黏素E(E-cadherin)蛋白的表达及其与临床病理因素的关系.方法:应用免疫组织化学光/微波(LW/MW)-EliVisionTM法,检测100例结直肠癌组织中Ezrin和E-cadherin的表达情况,并分析其与结直肠癌浸润转移等的关系.结果:Ezrin和蛋白在结直肠癌组织中的阳性表达明显高于正常黏膜,而E-cadherin蛋白在正常黏膜中的阳性表达高于结直肠癌组织(P＜0.05).Ezrin的高表达与结直肠癌浸润深度、淋巴结是否转移有关(P＜0.05);而与TNM分期、分化程度无关(P＞0.05).E-cadherin的表达与结直肠癌分化程度、TNM分期、浸润深度及淋巴结是否转移有关(P＜0.05).二者在结直肠癌组织中的表达呈显著负相关(r=-0.673,P＜0.01).结论:Ezrin和E-cadherin蛋白在结直肠癌的发生、发展中起着重要作用,联合检测可为结直肠癌浸润转移和预后的判断提供理论依据.     

E-cadherin、β-catenin表达与结肠癌术后转移关系

目的 探讨结肠癌患者肿瘤组织中β-catenin、E-cadherin表达情况及其对远处转移的预测作用.方法 采用免疫组化方法检测其β-catenin、E-cadherin表达情况.结果 在35例转移组中23例(65.71％)患者出现β-catenin阳性表达,25例(71.42％)E-cadherin阳性表达,均高于非转移组.结肠癌β-catenin、E-cadherin的表达与原发灶分化程度、T分期和N分期均没有明显联系.肿瘤组织中β-catenin、E-cadherin表达明显高于癌旁组织.二者均为阳性表达,其转移率明显高于均为阴性表达转移率,生存分析显示不同表达状态其远处转移出现时间差异有统计学意义(P =0.0369).结论 肿瘤组织中β-catenin、E-cadherin表达同结肠癌术后转移发生相关,两者联合检测有助于评估肿瘤转移程度.     

5-杂氮-2′-脱氧胞苷对前列腺癌PC-3细胞生物学行为的影响

目的 检测E-cadherin基因在激素非依赖性前列腺癌(HIPC)细胞上的表达及启动子CpG岛甲基化,探讨甲基化抑制剂5-杂氮-2′-脱氧胞苷(5-Aza-CdR)对HIPC细胞的影响及意义.方法 2.5、5.0、10.0 μmol/L的5-Aza-CdR处理PC-3细胞72h后,甲基化特异性聚合酶链反应(MSP)方法检测CpG岛甲基化改变,逆转录—聚合酶链反应(RT-PCR)方法检测E-cadherin mRNA变化,Westernblot方法检测E-cadherin蛋白变化,Transwell小室检测细胞侵袭性改变.结果 HIPC的E-cadherin启动子CpG岛甲基化呈阳性,基因表达缺失,细胞侵袭性明显.经5-Aza-CdR作用之后,CpG岛甲基化阳性明显减弱(P＜0.05),E-cadherin基因恢复表达(P＜0.05),PC-3细胞的侵袭性下降约59.68％,且与药物的浓度呈正相关.结论 5-Aza-CdR可逆转PC-3细胞E-cadherin启动子CpG岛的异常甲基化,诱导mRNA转录和蛋白的表达,并降低癌细胞的侵袭性.     

多种转移潜能不同的人前列腺癌细胞“上皮细胞间质转化态”特性鉴定及其意义

目的:对多种转移潜能不同的人前列腺癌细胞“上皮细胞间质转化态”(EMT)特性进行鉴定,并从粘附因素和细胞骨架蛋白角度分析其骨转移潜能获得的分子机制。方法:用W estern印迹法鉴定LNCaP及其亚细胞系C4、C4-2和ArCaP亚细胞系IF11、IA8,以及PC-3、Du145等细胞中上皮型钙粘素(E-cadherin)、神经型钙粘素(N-cadherin)和波形纤维蛋白(V im entin)的表达差异情况,并分析其在前列腺癌转移过程中的作用。结果:E-cad-herin在PC-3、LNCaP、C4、C4-2中表达较高,但在Du145、IF11、IA8中表达极低;而V im entin的表达情况恰恰与E-cadherin相反;N-cadherin在IF11、IA8细胞中呈现显著的高表达状态。结论:转移潜能不同的人前列腺癌细胞株之间存在EMT表型的表达差异,其中PC-3、LNCaP、C4、C4-2是未发生EMT改变的细胞,Du145、IF11、IA8却是EMT化的细胞。EMT表型差异蛋白在解释前列腺癌转移机制方面占据着重要地位。