CK1δ与COX-2在食管鳞状细胞癌的表达及其意义

目的：探讨CK1δ与COX-2蛋白在食管鳞状细胞癌中的表达与食管癌临床病理特征之间的关系。方法：用免疫组织化学方法（SP法）检测了63例食管鳞状细胞癌手术切除的癌组织、癌旁组织（30例正常食管上皮、19例羟度不典型增生、14例重度不典型增生组织）中的CK1δ与COX-2的蛋白的表达。并采用流式细胞术对其中随机选取的40例癌组织、18例轻度不典型增生组织、12例重度不典型增生组织和20例正常食管上皮组织进行上述两种蛋白的定量分析，采用SPSS11．5软件进行统计学处理。结果：在正常食管上皮组织中CK1δ和COX-2蛋白的表达显著低于轻度不典型增生组织、重度不典型增生组织和癌组织（P〈0．01），轻度不典型增生组织显著低于癌组织（P〈0．01），轻度不典型增生组织与重度不典型增生组织比较差异无显著（P〉0．05）．重度不典型增生组织和癌组织的比较差异无显著性（P〉0．05）。在癌组织中。淋巴结转移组中CK1δ蛋白的表达显著高于无淋巴结转移组（P〈0．01）．CK1δ蛋白的表达与分化程度和有无纤维膜的侵及无关（P〉0．05）；淋巴结转移组中COX-2蛋白的表达显著高于无淋巴结转移组（P〈0．01），有纤维膜侵及组中COX-2蛋白的表达显著高于无纤维膜侵及组（P〈0．01），COX-2蛋白的表达与分化程度无关（P〉0．05）。在食管鳞癌组织中CK1δ蛋白与COX-2蛋白之间呈显著正相关（r=-0．482，P〈0．01）。结论：CK1δ、COX-2蛋白的异常表达可能共同参与了食管鳞癌的发生、发展与转移，有望成为评价食管癌恶性程度和转移的指标。     

RUNX3与OPN在食管鳞癌组织中的表达及其临床意义

目的研究RUNX3与OPN在食管鳞癌发生、发展、浸润和转移中的作用以及临床意义。方法免疫组化检测60例食管鳞癌病人的食管正常黏膜组织、癌旁不典型增生组织及鳞癌组织中RUNX3蛋白和OPN蛋白的表达情况。结果RUNX3在正常食管黏膜组织、癌旁不典型增生组织及食管癌组织中分别为78．33％（47／60）、43．48％（10／23）、31．67％（19／60）。RUNX3的表达与食管鳞癌浸润深度和分期均明显相关（P〈0．05）。OPN在正常食管黏膜组织、癌旁不典型增生组织及食管癌组织中分别为0％（0／60）、34．78％（8／23）及76．67％（46／60）,OPN的表达与食管鳞癌浸润深度、淋巴结转移和分期均明显相关（P〈0．05）。RUNX3和OPN在食管鳞癌组织、癌旁不典型增生及正常食管黏膜组织中的表达呈明显的负相关（P〈0．05）。结论两者联合检测对探讨食管鳞癌的发生、发展、浸润、淋巴结转移及预后判断可能会有更大的意义。     

食管鳞状细胞癌组织中整合素β1和上皮钙粘附素表达与侵袭和转移的关系

目的：探讨食管鳞状细胞癌组织中整合素β1（integrinβ1,INTβ1）和E-cd表达与侵袭和转移的关系。方法：应用免疫组化SP法检测54例食管鳞状细胞癌及8例正常食管黏膜组织中INTβ1和上皮钙粘附素（epithelial cadherin,E-cd）的表达,分析其与临床病理特征的关系。结果：54例食管鳞状细胞癌组织中INTβ1正常表达率为18．5％（10／54）,E-cd为25．9％（14／54）;8例正常食管上皮组织中INTβ1正常表达率为5／8,E-cd为7／8,差异均有统计学意义,P〈0．05。食管鳞状细胞癌组织中INTβ1（rs=-0、313,P=0．021）和E-cd（rs=-0．342,P=0．011）表达程度与组织学分级呈负相关;E-cd与淋巴结转移呈负相关,rs=-0．289,P=0．034。结论：食管鳞状细胞癌组织中INTβ1和E-cd蛋白表达降低,影响肿瘤细胞分化、生长、侵袭和转移。     

蛋白水解诱导因子在食管鳞状细胞癌中的表达

目的：研究蛋白水解诱导因子（proteolysis-inducing factor,PIF）在食管鳞状细胞癌中的表达及意义。方法：应用免疫组化方法,检测PIF在107例食管鳞状细胞癌病人癌组织以及其中35例癌旁正常组织以及8例食管良性疾病标本中的表达情况,并探讨PIF表达与食管癌临床分期、肿瘤分化程度的关系。结果：食管鳞状细胞癌组织中存在PIF表达,其表达与食管良性疾病对照组中的表达差异有统计学意义（P〈0．05）,肿瘤组织中表达PIF的个体其癌旁正常组织中亦有PIF表达,PIF表达在肿瘤分化、是否侵及浆膜层、有无淋巴结转移和肿瘤分期中的差异无统计学显著性（P〉0．05）。结论：食管鳞状细胞癌组织中存在PIF表达,其表达与肿瘤分化、是否侵及浆膜层、有无淋巴结转移和肿瘤分期无关。     

GST-π在不同食管病变组织中的表达及意义

目的探讨GST-π在不同食管病变组织中的表达及意义。方法应用免疫组织化学S-P法检测50例食管鳞癌及其周围正常食管黏膜、20例食管黏膜轻度不典型增生、20例食管黏膜重度不典型增生组织中GST-π的表达。结果在正常黏膜、轻度不典型增生、重度不典型增生及鳞状细胞癌组织中GST-π阳性率分别为82％、75％、60％、52％。癌组织及重度不典型增生组织中GST-π的表达明显低于正常黏膜及轻度不典型增生组织中的表达（P〈0．05）,但正常食管黏膜与轻度不典型增生之间及重度不典型增生和癌组织之间GST-π的表达差异无统计学意义（P〉0．05）。结论GST-π与食管癌的发生密切相关。     

Bub1在食管鳞状细胞癌组织和正常食管黏膜的表达及临床意义

目的：观察Bub1 mRNA及Bub1蛋白在食管鳞状细胞癌和正常食管黏膜组织中的表达差别,探讨Bub1在食管鳞状细胞癌发生、发展中的作用及其临床意义。方法：收集40例食管鳞状细胞癌标本及相应的食管切缘正常黏膜组织,利用免疫组化染色及原位杂交技术检测Bub1蛋白和Bub1 mRNA在食管鳞状细胞癌组织和正常食管黏膜组织中的表达。结果：与正常黏膜组织相比较,Bub1 mRNA及Bub1蛋白在食管鳞状细胞癌组织中表达水平明显降低（P〈0.005）,且Bub1 mRNA及Bub1蛋白的表达水平与食管鳞状细胞癌分化程度及有无淋巴结转移相关（P〈0.05）。结论：Bub1表达水平高低可能与食管鳞状细胞癌的发生发展及淋巴结转移具有一定关系。     

p-JNK JNK和PPAR γ在食管癌变过程中的

目的：探讨p-JNK JNK和PPAR γ蛋白在食管癌变过程中的表达及其意义。方法：采用免疫组织化学方法，研究食管正常鳞状上皮（15例）、食管鳞状上皮内瘤变（85例）和食管鳞状细胞癌（60例）组织中p-JNK JNK和PPAR γ蛋白的表达情况。结果：JNK在食管正常鳞状上皮、食管鳞状上皮内瘤变和食管鳞状细胞癌中的阳性表达率分别为20．0％、37．6％和55．0％，而p-JNK的阳性表达率分别为33．3％、55．3％和73.3％，JNK和p-JNK在食管鳞状细胞癌中的阳性表达率均明显高于食管正常鳞状上皮和食管鳞状上皮内瘤变（P〈0．05）。高级别食管鳞状上皮内瘤变中JNK、p-JNK的阳性表达率显著高于食管正常鳞状上皮和低级别食管鳞状上皮内瘤变（P〈0．05）。PPAR γ在食管正常鳞状上皮、食管鳞状上皮内瘤变和食管鳞状细胞癌中的阳性表达率分别为733％、45．9％和45．0％，食管鳞状上皮内瘤变和食管鳞状细胞癌中PPAR γ的阳性表达率明显低于食管正常鳞状上皮（P〈0．05）。食管鳞状细胞癌中JNK、p-JNK和PPAR3,的表达与肿瘤分化程度相关，JNK、p-JNK和PPAR3,的表达均随肿瘤病理分级的增高而降低（P〈0．05）。JNK、P—JNK和PPAR γ的表达与临床病理特征不相关（P〉0．05）。结论：在食管癌变过程中，JNK、p-JNK的表达呈增高趋势而PPAR γ的表达呈下降的趋势。但食管鳞状细胞癌中JNK／p—JNK和PPAR γ,的表达均随肿瘤分化程度降低而降低。提示JNK、p-JNK和PPAR γ在食管鳞状上皮癌变和进展过程中发挥不同作用，其机制比较复杂。     

Mel-18和Bmi-1在食管鳞状细胞癌中的表达及其临床意义

目的探讨Mel-18和Bmi-1在食管鳞状细胞癌中的表达及其临床意义。方法采用实时定量聚合酶链反应（QRT—PCR）及Westernblot方法检测29例食管鳞状细胞癌组织及配对癌旁组织中Mel-18和Bmi-1mRNA的表达。另选取芯片库中60例食管鳞状细胞癌及癌旁组织。免疫组织化学方法检测以上所有89例食管鳞状细胞癌组织及配对癌旁组织中Mel-18和Bmi-1蛋白的表达,分析二者在食管鳞状细胞癌中的表达情况与各临床病理因素之间的关系。结果QRT．PCR结果显示食管鳞状细胞癌中Mel-18mRNA阴性表达率为55．17％（16／29）,Bmi．1mRNA阳性表达率为62．07％（18／29）。Westernblot结果显示,与癌旁组织比较,食管鳞状细胞癌中Mel-18蛋白低表达（0．724±0．095比0．899±0．089,t=2．319,P=0．028）,Bmi．1蛋白高表达（0．980±0．068比0．729-1-0．066,t=2．863,P=0．008）,差异均有统计学意义。免疫组织化学结果显示食管鳞状细胞癌组织中Mel-18的阴性表达率高于癌旁组织,差异有统计学意义[66．3％（59／89）比31．5％（28／89）,X。21．606,P〈0．05];食管鳞状细胞癌中Bmi-1的阳性表达率高于癌旁组织,差异具有统计学意义[74．2％（66／89）比30．3％（27／89）,Х^2=34．249,P〈0．05]。89例食管鳞状细胞癌患者中,Mel-18表达与肿瘤的临床分期（Х^2=8．003,P=0．004）、浸润深度（Х^2=17．094,P=0．001）、淋巴结转移（Х^2=5．156,P=0．026）相关,Bmi-1表达与分化程度（Х^2=14．625,P=0．001）、临床分期（Х^2=7．863,P=0．005）、淋巴结转移（Х^2=5．771,P=0．005）相关。另外,通过QRT—PCR及免疫组织化学检测发现在食管鳞状细胞癌中Mel-18和Bmi-1的表达负相关（r=-0．592,P=0．001;r=-0．285,P=0．007）。结论在食管鳞状细胞癌的发生发展中,Mel-18可能起抑癌作用,而Bmi-1可能起致癌作用,二者可望成为食管鳞状细胞癌明确诊断及判断预后的新指标。     

PTEN在食管鳞状细胞癌中的表达和临床意义

目的：研究抑癌基因PTEN蛋白表达与食管鳞状细胞癌临床病理特征的关系,探讨其在食管癌变中的可能作用。方法：应用免疫组织化学SP法检测60例食管鳞状细胞癌及20例癌旁正常组织中PTEN蛋白的表达,结合临床资料进行分析。结果：PTEN蛋白阳性反应主要定位于胞浆。食管鳞状细胞癌组织中PTEN蛋白表达阳性率56．7％明显低于正常组织阳性率90．0％（P〈0．05）。PTEN蛋白在低分化、中分化、高分化鳞癌组的阳性表达率分别是21．4％、55．0％、76．9％,三组之间相互比较有极显著统计学差异（P〈0．01）,肿瘤分化程度越低PTEN蛋白表达越低。有淋巴细胞转移的食管癌组织中VrEN表达的阳性率42．9％明显低于无淋巴细胞转移的食管癌组织阳性率76．0％（P〈0．05）。有外膜浸润的食管癌组织中PTEN表达的阳性率26．1％明显低于无外膜浸润的食管癌组织阳性率75．7％（P〈0．05）。PTEN蛋白在食管癌早期表达高于晚期（P〈0．01）。结论：PTEN蛋白在食管鳞状细胞癌组织中的低表达可能与食管鳞癌的发生发展有重要关系。     

食管鳞癌组织中GRIM-19的表达及意义

目的探讨干扰素／维甲酸联合应用诱导细胞凋亡相关基因-19（GRIM-19）蛋白在食管鳞癌组织中的表达及意义。方法运用免疫组化技术检测68例食管鳞癌、35例癌旁不典型增生及68例正常食管黏膜组织中GRIM-19蛋白表达;采用TUNEL方法检测食管鳞癌组织中的细胞凋亡。结果1）GRIM-19蛋白在正常食管黏膜组织、癌旁不典型增生组织及食管鳞癌组织中的阳性表达率分别为80．9％（55／68）、34．3％（12／35）和11．8％（8／68）,两两比较差异均有统计学意义（P均〈0．05）;2）食管鳞癌组织中肿瘤细胞的凋亡与GRIM-19蛋白表达有关,GRIM-19蛋白阳性表达组中肿瘤细胞AI为（5．06±0．93）％,显著高于阴性表达组的（1．12±0．06）％,差异有统计学意义（P〈0．05）。结论GRIM-19蛋白的低表达可能与食管鳞癌的细胞凋亡有关。     

DNA methylation in esophageal diseases including cancer: special reference to hMLH1 gene promoter status

AIMS AND BACKGROUND: Chronic inflammation leading to malignancy in the esophagus may be due to errors in mismatch repair (MMR) genes such as hMLH1. Promoter hypermethylation has been suggested as the main cause of hMLH1 silencing. In this study we assessed hMLH1 promoter hypermethylation in a range of esophageal diseases. Further, we evaluated the role of factors affecting the methylation cycle: (1) methylenetetrahydrofolate reductase (MTHFR) C677T mutation and (2) serum homocysteine levels. METHODS: We endoscopically and histologically categorized 124 paired tissue and blood samples from patients into cancer, precancer, reflux esophagitis, other inflammatory esophagitis and controls (endoscopically normal). Restriction enzyme-based methylation analysis was carried out to assess hMLH1 promoter hypermethylation. RESULTS AND CONCLUSIONS: hMLH1 promoter hypermethylation in tissue was seen in 63.5% of patients with cancer and 53.8% of those with precancer, which was significantly increased when compared with controls (P < 0.001). There appears to be an increasing degree of hMLH1 hypermethylation with disease progression. Patients with gastroesophageal reflux disease (GERD) showed a high degree of hMLH1 hypermethylation (88.8%), indicating that local environment due to reflux may be promoting hypermethylation. We suggest that GERD is a progressive condition with an increased risk for developing into cancer. Only 14.5% of cases exhibited hypermethylation both in tissue and blood. Hence, we conclude that hMLH1 promoter hypermethylation is a tissue-specific change in the esophagus and blood testing cannot be used as a noninvasive tool to assess it. DNA methylation is dependent on the methylation cycle; MTHFR is a major enzyme in this pathway. MTHFR mutations did not correlate with hypermethylation or clinical pathology (P > 0.5). Elevated homocysteine levels, independent of MTHFR mutation, correlated significantly with hMLH1 hypermethylation in tissue (P < 0.005). Our study shows that hMLH1 hypermethylation in tissue may be the primary event caused by endogenous/exogenous factors in esophageal diseases, aiding disease progression.     

Correlation of hMLH1 and HPP1 hypermethylation in gastric, but not in esophageal and cardiac adenocarcinoma

Using methylation-specific real-time PCR, we determined the prevalence of aberrant methylation in the mismatch repair gene hMLH1 and in the recently described HPP1 gene among 50 esophageal, 50 cardiac and 50 gastric ADCs. Additionally, expression of hMLH1 protein was detected immunohistochemically and correlated with DNA MSI. Hypermethylation of hMLH1 was found in 14% of esophageal, 28% of cardiac and 32% of gastric ADCs, whereas HPP1 hypermethylation was found more frequently in the 3 tumor types (64% vs. 38% vs. 54%). In gastric ADC, HPP1 hypermethylation was found more frequently in tumors with concomitant hMLH1 hypermethylation (81%) than in those without hMLH1 hypermethylation (41%, p = 0.008). Complete loss of hMLH1 protein expression, which was present in 10 carcinomas (5 cardiac and 5 gastric), was invariably correlated with hMLH1 hypermethylation and MSI. In conclusion, our data indicate that MSI and loss of the mismatch repair protein hMLH1, which is mainly caused by hMLH1 gene hypermethylation, are more prevalent in stomach and cardia carcinogenesis than in that of the esophagus. Moreover, in gastric cancer, hMLH1 hypermethylation is correlated with hypermethylation of the HPP1 gene.     

lncRNA XIST调控miR-486-5p影响食管癌细胞增殖的实验研究

目的:探讨lncRNA XIST在食管癌组织中的表达情况以及其对食管癌细胞增殖的影响。方法:实时定量PCR检测23对食管癌及癌旁组织中lncRNA XIST的表达水平。采用lncRNA XIST siRNA转染lncRNA XIST表达最高的两株食管癌细胞，实时定量PCR检测转染效率；CCK-8检测细胞增殖情况；双荧光素酶报告基因检测lncRNA XIST与miR-486-5p的结合情况；实时定量PCR进一步检测miR-486-5p的表达。结果:实时定量PCR结果显示与癌旁组织相比食管癌组织中lncRNA XIST的表达水平显著升高（P＜0.01）。此外，在三株食管癌细胞中lncRNA XIST在Eca-109和TE-1细胞中表达最高。在Eca-109和TE-1细胞中转染lncRNA XIST siRNA后lncRNA XIST的表达水平分别降低了（75.50±0.89）%和（64.74±13.42）%。下调lncRNA XIST显著抑制食管癌细胞的增殖。双荧光素酶报告基因检测结果显示wt-XIST和miR-486-5p mimic共转染的细胞荧光素酶活性显著降低（P＜0.01）。此外，下调lncRNA XIST后两株细胞中miR-486-5p的表达水平均显著升高（P＜0.01）。结论:lncRNA XIST与食管癌的恶性进展密切相关，lncRNA XIST有望成为食管癌治疗的新靶点。     

Fruits, vegetables, and hMLH1 protein-deficient and -proficient colon cancer: The Netherlands cohort study.

BACKGROUND: Clinical and pathologic differences exist between colon carcinomas deficient and proficient in the mismatch repair protein hMLH1. Animal and in vitro studies suggest that fruits, vegetables, folate, and antioxidants are associated with colonic expression of mismatch repair genes.METHODS: Associations between consumption of fruits and vegetables and hMLH1 protein-deficient and -proficient colon cancer were evaluated in the Netherlands Cohort Study on diet and cancer using a case-cohort approach. A self-administered food frequency questionnaire was completed, in 1986, by 120,852 individuals ages 55 to 69 years. Using immunohistochemistry, hMLH1 protein expression was assessed in colon cancer tissue obtained from 441 patients who were identified over 7.3 years of follow-up excluding the initial 2.3 years. Incidence rate ratios (RR) were estimated for hMLH1 protein-deficient and -proficient colon cancer.RESULTS: hMLH1 protein expression was absent in 54 tumors (12.2%) and present in 387 tumors. Fruit consumption was associated with hMLH1 protein-deficient colon cancer [highest versus lowest tertile, RR, 0.46; 95% confidence interval (95% CI), 0.23-0.90; P(trend) = 0.029] but not with hMLH1 protein-proficient tumors (highest versus lowest tertile, RR, 1.03; 95% CI, 0.78-1.35; P(trend) = 0.81). Total consumption of vegetables was not associated with either type of tumor (hMLH1 protein deficient: RR, 0.86; 95% CI, 0.45-1.65; P(trend) = 0.67; hMLH1 protein proficient: RR, 0.94; 95% CI, 0.72-1.23; P(trend) = 0.72). No associations were observed for folate, fiber, antioxidants, or subgroups of vegetables.CONCLUSION: These analyses indicate that an inverse association between consumption of fruits and colon cancer may be confined to the subgroup of tumors with a deficient mismatch repair system.     

幽门螺杆菌感染对胃黏膜细胞hMSH2,hMLH1和p53基因表达的影响

目的探讨幽门螺杆菌(Helicobacterpylori,H.pylon)感染与胃癌、癌旁及胃炎黏膜中hMSH2,hMLH1和p53基因表达的关系,进一步了解H.pylori在胃癌发生中的作用。方法采用快速尿素酶方法检测H.pylori;采用免疫组化SP法检测hMSH2,hMLH1和p53基因表达。结果(1)hMSH2在胃癌中的表达阳性率(62.7%)显著高于癌旁(29.4%),胃炎黏膜(32.4%)和正常对照(30.0%)(P<0.001)。其中在低分化腺癌中阳性率(76.4%)显著高于高中分化腺癌(54.3%)和黏液癌(53.1%)(P<0.05);hMLH1在胃癌中的表达阳性率(64.3%)显著低于癌旁(84.4%),胃炎黏膜(82.4%)和正常对照(80.0%)(P<0.01)。其中在黏液癌的阳性率(43.7%)显著低于其他两种腺癌(78.2%,64.7%)(P<0.01);p53在胃癌中的表达阳性率(51.9%)显著高于癌旁(3.1%),胃炎黏膜(0.0%)和正常对照(0.0%)(P<0.001)。其中,在高中分化腺癌的阳性率(32.6%)显著低于黏液癌(68.7%)和低分化腺癌(58.8%)(P<0.05)。(2)在全部被检组织中,H.pylori感染组hMSH2和hMLH1的表达阳性率均低于相应的非感染组。其中,胃癌H.pylori感染组hMSH2的表达阳性率(52.8%)显著低于非感染组(74.5%)(P<0.05)。胃癌H.pylori感染组p53的表达阳性率(61.4%)显著高于非感染组(40.6%)(P<0.05)。结论胃癌的发生发展可能与hMSH2,hMLH1和p53基因的异常表达有关;H.pylori感染影响这三种基因的正常表达,这可能是H.pylori致癌的机制之一。     

Mucin expression profile in Barrett's, dysplasia, adenocarcinoma sequence in the esophagus

BACKGROUND: The molecular events that accompany the progression to adenocarcinoma (ADC) of the esophagus are poorly understood. Aberrant mucin receptor expression can contribute to increased cell growth and metastatic ability. AIM: The aim of this study was to establish a pattern for mucin (MUC) gene expression in the esophageal mucosa under normal and pathological conditions. SETTING: University Hospital Cancer Center Laboratory. Archived tissue samples studied in a retrospective fashion. MATERIALS AND METHODS: Tissue samples were obtained from the archives of patients with histological evidence of Barrett's esophagus (BE) progressing to ADC. Immunohistochemical analysis was performed using mouse monoclonal antibodies for MUC1, MUC2, MUC5AC, MUC6. Semiquantitative scoring of histological staining was performed using a linear scoring system: 0-staining absent; 1-staining in 0-25%; 2-staining in 25-50%; and 3-staining in 50-75% of the epithelium. The Binomial test was used to explore trends and differences in frequency of mucin expression along the pathological sequence. RESULTS: Only mild superficial staining of MUC1 was seen in normal squamous epithelium. MUC1 and MUC2 were uniformly expressed in all samples (7/7) of BE and dysplasia (P=0.008). MUC1 expression was upregulated (7/7) in progression to adenocarcinoma (P=0.008). The secretory mucins, MUC5AC and MUC6 showed a decrease in expression with progression from BE to dysplasia to ADC (P< 0.05). CONCLUSIONS: Downregulation of MUC5AC and MUC6 decreases mucosal protection against gastric acid. Increasing MUC1 expression is associated with progression from dysplasia to ADC. Upregulation of MUC2 reflects intestinal metaplasia in BE.     

幽门螺杆菌感染对胃黏膜细胞hMSH2,hMLH1和p53基因表达的影响(英文)

目的探讨幽门螺杆菌(Helicobacter pylori,H.pylori)感染与胃癌、癌旁及胃炎黏膜中 hMSH2,hMLH1和 p53基因表达的关系,进一步了解 H.pylori 在胃癌发生中的作用。方法采用快速尿素酶方法检测 H.pylori;采用免疫组化 SP 法检测 hMSH2,hMLH1和 p53基因表达。结果 (1)hMSH2在胃癌中的表达阳性率(62.7%)显著高于癌旁(29.4%),胃炎黏膜(32.4%)和正常对照(30.0%)(P<0.001)。其中在低分化腺癌中阳性率(76.4%)显著高于高中分化腺癌(54.3%)和黏液癌(53.1%)(P<0.05);hMLH1在胃癌中的表达阳性率(64.3%)显著低于癌旁(84.4%),胃炎黏膜(82.4%)和正常对照(80.0%)(P<0.01)。其中在黏液癌的阳性率(43.7%)显著低于其他两种腺癌(78.2%,64.7%)(P<0.01);p53在胃癌中的表达阳性率(51.9%)显著高于癌旁(3.1%),胃炎黏膜(0.0%)和正常对照(0.0%)(P<0.001)。其中,在高中分化腺癌的阳性率(32.6%)显著低于黏液癌(68.7%)和低分化腺癌(58.8%)(p<0.05)。(2)在全部被检组织中,H.pylori 感染组 hMSH2和 hMLH1的表达阳性率均低于相应的非感染组。其中,胃癌 H.pylori感染组 hMSH2的表达阳性率(52.8%)显著低于非感染组(74.5%)(P<0.05)。胃癌 H.pylori 感染组 p53的表达阳性率(61.4%)显著高于非感染组(40.6%)(P<0.05)。结论胃癌的发生发展可能与 hMSH2,hMLH1和 p53基因的异常表达有关;H pylori 感染影响这三种基因的正常表达,这可能是H.pylori 致癌的机制之一。     

幽门螺杆菌对胃癌hMLH1和hMSH2基因表达的影响

目的探讨幽门螺杆菌(Hp)对胃癌中hMLH1和hMSH2基因表达的影响和Hp的致癌机制.方法利用免疫组织化学S-P法检测胃癌、癌旁和胃炎黏膜中hMLH1、hMSH2 基因的表达情况.结果在全部被检组织中,Hp感染组hMLH1和hMSH2表达阳性率均低于相应的非感染组,其中胃癌组织中hMSH2表达阳性率在Hp感染组(54.7%)和非感染组(82.1%)差异有显著性(P<0.05).结论 Hp感染引起hMLH1和hMSH2基因表达降低,这可能是Hp导致胃癌的分子机制之一.     

Loss of expression of DNA repair enzymes MGMT,hMLH1, and hMSH2 during tumor progression in gastric cancer

BACKGROUND: Disorders of the DNA repair system that protects against alkylating mutagens are known to play an important role in carcinogenesis. METHODS: We investigated the expression of the DNA repair enzyme that protects against alkylating mutagens, O(6)-methylguanine DNA methyltransferase (MGMT), and the mismatch repair (MMR) enzymes, hMLH1 and hMSH2, in 135 gastric cancer specimens by immunohistochemical means. RESULTS: The immunoreactivity of MGMT and MMR proteins correlated significantly with several clinicopathologic factors. The survival curve in 116 patients showed that a loss of MGMT or hMLH1, but not of hMSH2, correlated with a poor prognosis. Combined evaluation of MGMT and hMLH1 revealed that the survival of patients with negative status for both MGMT and hMLH1 was shortest. However, this significant association between patient survival and MGMT or hMLH1 expression disappeared when early and advanced cancers were separately analyzed, indicating that synchronous losses of MGMT and hMLH1 increase during tumor progression and stage. Further evaluation according to histologic type revealed that loss of MGMT, hMLH1, and hMSH2 expression significantly differed between early and advanced cancer in differentiated-type cancers. In contrast, in undifferentiated-type cancer, loss of MGMT and MMR expression was frequently found even in intramucosal (m) cancer, and no significant difference was found in loss of hMLH1 and hMSH2 between early and advanced cancer. CONCLUSION: These findings demonstrate that the reduced expression of MGMT, hMLH1, and hMSH2 in differentiated-type cancer may play an important role during tumor progression between the early and advanced stage. On the other hand, in undifferentiated-type cancer, loss of MGMT and the MMR proteins appears to be an important event at carcinogenesis or at an earlier step of tumor progression.     

错配修复基因hMSH2和hMLH1在胃癌组织中的表达及其与幽门螺杆菌感染的关系

胃癌是一种多因素相关疾病,幽门螺杆菌(helicobactor pylori,HP)感染是导致胃癌发生的原因之一,但其分子机制不明。错配修复基因是保证DNA复制高保真度的重要基因,与消化道肿瘤发生具有密切关系。本研究通过检测HP感染和非感染胃癌组织及癌旁粘膜组织和慢性浅表性胃炎粘膜组织中错配修复基因hMSH2和hMLHl蛋白的表达,探讨hMSH2、hMLHl基因在胃癌发生中的作用和HP致癌的可能机制。