APC基因异常甲基化在上皮性卵巢癌中的检测及临床意义

目的探讨结肠腺瘤性息、肉病基因（APC）异常甲基化在上皮性卵巢癌发生、发展中的作用及临床意义。方法采用甲基化特异性PCR法检测63例上皮性卵巢癌组织原发灶、41例相应的盆腹腔转移灶、10例癌旁卵巢组织及20例正常卵巢组织中APC基因启动子区甲基化状态。结果上皮性卵巢癌组织原发灶及相应的盆腹腔转移灶中APC基因启动子区异常甲基化发生率分别显著高于正常卵巢组织（P〈0．05）。APC基因启动子区甲基化与上皮性卵巢癌临床分期、分化程度及病理类型无关。结论APC基因启动子区异常甲基化与上皮性卵巢癌发生、发展密切相关。     

甲状腺乳头状癌组织中TSHR基因启动子甲基化研究

目的探讨甲状腺乳头状癌组织中促甲状腺激素受体基因（Thyroid Stimulating Hormone Receptor,TSHR）基因启动子区5端CpG岛甲基化改变的特点与临床特征的关系。方法采用甲基化特异性PCR（MSP,methylation-specific PCR）方法检测TSHR基因启动子甲基化情况。结果（1）22／34例甲状腺乳头状癌组织中检测到TSHR基因启动子甲基化,9／34例甲状腺乳头状癌癌旁组织中检测到TSHR基因启动子甲基化,癌组织中TSHR基因启动子甲基化率显著增高（χ^2=10．019,P=0．002〈0．05）;（2）有淋巴结转移的甲状腺乳头状癌组织（15／18例）TSHR基因启动子的甲基化显著高于无淋巴结转移组（7／16例）（χ^2=5．812,P=0．016〈0．05）。结论TSHR基因启动子异常甲基化是甲状腺乳头状癌发展过程中的分子事件之一,可能影响了甲状腺乳头状癌细胞的摄碘的功能。     

胃癌组织中E—cadherin基因启动子异常甲基化状态观察

目的观察胃癌组织中E—cadherin基因启动子异常甲基化状态。方法采用甲基化特异性聚合酶链反应（MSP）技术检测54例胃癌及其癌旁正常组织中的E—cadherin基因启动子异常甲基化状态,并分析E-cadherin基因启动子异常甲基化状态与胃癌临床病理参数的关系。结果胃癌组织中的E-cadherin基因启动子异常甲基化发生频率为48．10％（26／54）,明显高于癌旁正常组织中的11．11％（6／54）。E—cadherin基因启动子异常甲基化频率与胃癌分化程度、病理类型、浸润深度以及淋巴结转移、临床分期有关（P均〈0．05）。结论胃癌组织中E-cadherin基因启动子异常甲基化频率较高,并与胃癌浸润、转移有关。     

肺癌组织中RKIP基因启动子区甲基化状态观察

目的观察肺癌组织中Raf激酶抑制蛋白（RKIP）基因启动子区甲基化状态变化,探讨其与肺癌临床病理特征的关系。方法采用RT-PCR和甲基化特异性PCR法（MSP）分析肺癌及相应癌旁肺组织中RKIP基因表达情况及其启动子区甲基化状态。结果肺癌组织中RKIP基因启动子区甲基化率为45．8％（27／56）,明显高于癌旁肺组织的13．3％（2／56）,P〈0．05。所有甲基化的肺癌组织中RKIP基因均无表达。有淋巴结转移的43例肺癌组织中,27例RKIP基因启动子甲基化;无淋巴结转移的40例中,11例RKIP基因启动子甲基化（P〈0．05）。结论肺癌组织中RKIP基因失表达与其启动子区甲基化有关,这可能是肺癌发生发展以及转移的原因之一。     

胃癌患者血清RASSF1A基因启动子区甲基化检测

Ras相关结构域家族1A（RASSF1A）基因是近年发现的新型抑癌基因，其启动子区甲基化可能与胃肠道肿瘤的发生、发展密切相关。目的：检测胃癌患者血清RASSF1A基因启动子区甲基化情况，探讨其在胃癌早期诊断和预后评估中的可能作用。方法：以甲基化特异性聚合酶链反应（MSP）检测47例胃腺癌患者、30例胃良性病变患者和30名健康对照者的血清RASSF1A基因启动子区甲基化情况，其中16例胃腺癌患者同时留取手术切除癌组织、癌旁组织标本以及术前、术后血标本行对照研究。结果：胃腺癌患者血清RASSF1A基因启动子区甲基化率为34．0％（16／47），显著高于胃良性病变患者（3.3％，1／30）和健康对照者（0％）（P〈0．01）。16例胃腺癌组织中5例（31．2％）检测到RASSF1A基因启动子区甲基化，其中4例（80．0％）术前、术后血清标本均检测到RASSF1A基因启动子区甲基化。血清RASSF1A基因启动子区甲基化与胃癌患者性别、年龄、肿瘤分化程度、有无转移以及血清癌胚抗原（CEA）水平均无相关性。结论：血清RASSF1A基因启动子区甲基化检测可望为胃癌的早期诊断和预后判断提供依据。     

胃癌维甲酸信号通路相关基因启动子区协同高甲基化的研究

背景：启动子区高甲基化与胃癌中多种抑癌基因表达沉默密切相关。目的：探讨维甲酸信号通路相关基因维甲酸受体B（RAR13）、细胞维生素A结合蛋白1（CRBP1）和他扎罗汀诱导基因1（TIG1）启动子区高甲基化与胃癌的关系。方法：以甲基化特异性聚合酶链反应（MSP）检测40例胃癌标本、10例正常胃黏膜标本和6株胃癌细胞株的RAR13、CRBPI和TIG1基因启动子区甲基化状态，分析i者甲基化状态的相关性及其与胃癌1晦床病理特征的关系。以逆转录聚合酶链反应（RT—PCR）检测胃癌细胞株RAR13、CRBP1和TIG1mRNA表达。结果：40例胃癌组织的RAR13、CRBPI和TIG1基因甲基化率分别为45．0％、32．5％和57．5％，10例正常胃黏膜组织均未检测到上述基因甲基化（P〈0．05）。胃癌组织中RAR13的甲基化状态与CRBP1和TIG1的甲基化状态显著相关（P〈0．05），但三者的甲基化状态与胃癌临床病理特征无相关性。启动子区高甲基化胃癌细胞株相应基因mRNA表达缺失或减弱。结论：胃癌组织常发生维甲酸信号通路相关基因RAR13、CRBP1和TIG1启动子区高甲基化，高甲基化可能是相应基因转录失活的重要原因。     

hMLH1基因高甲基化在胃癌发生、发展中的作用

基因启动子区CpG岛甲基化使许多基因失活，从而导致恶性肿瘤的发生和发展。目的：检测hMLHl基因启动子区CpG岛甲基化水平，探讨其胃癌发生、发展中的作用。方法：以甲基化特异性聚合酶链反应（MSP）检测41例胃癌、40例癌前病变和38例对照组织中hMLHl基因启动子区CpG岛甲基化状态，并分析其与胃癌患者临床病理特征的关系。结果：胃癌组织中hMLHl基因启动子区CpG岛甲基化阳性率为34．1％，显著高于癌前病变组的5．0％和对照组的0％（P〈0．05）。hMLHl基因甲基化阳性率与胃癌患者的年龄和肿瘤浸润深度有关（阳性率分别为46．4％对7．7％和55．0％对14.3％，P〈0．05），与性别、肿瘤分化程度和淋巴结转移无关（阳性率分别为34．8％对33．3％、28．0％对43．8％和38．1％对30．0％）。结论：胃癌组织中存在hMLHl基因启动子区CpG岛高甲基化，可能与胃癌的发生、发展有关．且可能在老年胃癌患者的肿瘤发生过程中起重要作用。     

血浆Runx3基因启动子甲基化检测诊断早期肝细胞癌的临床价值

目的探讨血浆Runt相关转录因子3（Runx3）基因启动子甲基化检测诊断早期肝细胞癌（HCC）的临床价值。方法采用DNA甲基化特异性PCR方法,检测81例HCC患者的癌组织、癌旁正常组织及血浆Runx3基因启动子异常甲基化情况。结果癌旁正常组织未发现Runx3异常甲基化现象;癌组织Runx3异常甲基化率43．2％（35／81）,血浆39．5％（32／81）;血浆Runx3甲基化改变与癌组织甲基化改变显著相关（P〈0．05）。Runx3基因异常甲基化与HCC患者的临床病理参数无显著相关性（P〉0．05）。结论血浆Runx3基因启动子甲基化检测对早期诊断HCC有一定参考价值。     

食管鳞癌组织p16基因调控区甲基化及其蛋白表达研究

目的探讨p16基因在食管癌变过程中表达缺失与其启动子区甲基化的关系。方法采用MSP免疫组化方法,检测环太行山地区45例食管鳞癌患者癌组织p16基因启动子区甲基化状态及蛋白表达情况。结果p16基因在癌组织中表达异常41例（91．1％）,间变组织中表达异常38例（84．4％）,发生纯合型甲基化的组织分别为33例（73．3％）（癌组织）和32例（71．1％）（间变组织）,而其周围正常组织26例（57．8％）均发生了p16启动子区的杂合型甲基化。p16基因纯合型甲基化与癌组织、间变组织、p16蛋白表达缺失相关（P〈0．05）。结论该地区食管癌组织p16基因在癌前病变中p16启动子区即发生了纯合型甲基化、食管癌变的早期事件。p16基因启动子区甲基化可单独影响p16蛋白的正常表达。     

胃癌组织Runx3基因甲基化的检测及意义

目的探讨胃癌组织中Runx3基因甲基化情况及其意义。方法采用DNA甲基化特异性PCR技术（MSP）对35例胃癌患者手术切除的肿瘤组织及癌旁组织Runx3基因启动子区域甲基化进行检测,同时采用RT—PCR检测Runx3mRNA的表达。结果胃癌及癌旁组织Runx3基因的甲基化发生率分别为40．0％和8．5％;胃癌组织Runx3mRNA表达较癌旁正常组织下调（P〈0．05）;Runx3mRNA的表达与胃癌分化程度及淋巴结转移有关。结论Runx3基因甲基化是导致Runx3基因失活的主要原因之一,与胃癌的发生发展密切相关。     

Effects of dietary intake and genetic factors on hypermethylation of the hMLH1 gene promoter in gastric cancer

AIM: Hypermethylation of the promoter of the hMLH1 gene, which plays an important role in mismatch repair during DNA replication, occurs in more than 30% of human gastric cancer tissues. The purpose of this study was to investigate the effects of environmental factors, genetic polymorphisms of major metabolic enzymes, and microsatellite instability on hypermethylation of the promoter of the hMLH1 gene in gastric cancer. METHODS: Data were obtained from a hospital-based, case-control study of gastric cancer. One hundred and ten gastric cancer patients and 220 age- and sex-matched control patients completed a structured questionnaire regarding their exposure to environmental risk factors. Hypermethylation of the hMLH1 gene promoter, polymorphisms of the GSTM1, GSTT1, CYP1A1, CYP2E1, ALDH2 and L-myc genes, microsatellite instability and mutations of p53 and Ki-ras genes were investigated. RESULTS: Both smoking and alcohol consumption were associated with a higher risk of gastric cancer with hypermethylation of the hMLH1 gene promoter. High intake of vegetables and low intake of potato were associated with increased likelihood of gastric cancer with hypermethylation of the hMLH1 gene promoter. Genetic polymorphisms of the GSTM1, GSTT1, CYP1A1, CYP2E1, ALDH2, and L-myc genes were not significantly associated with the risk of gastric cancer either with or without hypermethylation in the promoter of the hMLH1 gene. Hypermethylation of the hMLH1 promoter was significantly associated with microsatellite instability (MSI): 10 of the 14 (71.4%) MSI-positive tumors showed hypermethylation, whereas 28 of 94 (29.8%) the MSI-negative tumors were hypermethylated at the hMLH1 promoter region. Hypermethylation of the hMLH1 gene promoter was significantly inversely correlated with mutation of the p53 gene. CONCLUSION: These results suggest that cigarette smoking and alcohol consumption may influence the development of hMLH1-positive gastric cancer. Most dietary factors and polymorphisms of GSTM1, GSTT1, CYP1A1, CYP2E1, ALDH2, and L-myc genes are not independent risk factors for gastric cancer with hypermethylation of the hMLH1 promoter. These data also suggest that there could be two or more different molecular pathways in the development of gastric cancer, perhaps involving tumor suppression mechanisms or DNA mismatch repair.     

Effects of dietary intake and genetic factors on hypermethyiation of the hMLH1 gene promoter in gastric cancer

AIM: Hypermethylation of the promoter of the hMLH1 gene, which plays an important role in mismatch repair during DNA replication, occurs in more than 30% of human gastric cancer tissues. The purpose of this study was to investigate the effects of environmental factors, genetic polymorphisms of major metabolic enzymes, and microsatellite instability on hypermethylation of the promoter of the hMLH1 gene in gastric cancer. METHODS: Data were obtained from a hospital-based, case-control study of gastric cancer. One hundred and ten gastric cancer patients and 220 age- and sex-matched control patients completed a structured questionnaire regarding their exposure to environmental risk factors. Hypermethylation of the hMLH1 gene promoter, polymorphisms of the GSTM1, GSTT1, CYP1A1, CYP2E1, ALDH2 and L-myc genes, microsatellite instability and mutations of p53 and Ki-ras genes were investigated. RESULTS: Both smoking and alcohol consumption were associated with a higher risk of gastric cancer with hypermethylation of the hMLH1 gene promoter. High intake of vegetables and low intake of potato were associated with increased likelihood of gastric cancer with hypermethylation of the hMLH1 gene promoter. Genetic polymorphisms of the GSTM1, GSTT1, CYP1A1, CYP2E1, ALDH2, and L-myc genes were not significantly associated with the risk of gastric cancer either with or without hypermethylation in the promoter of the hMLH1 gene. Hypermethylation of the hMLH1 promoter was significantly associated with microsatellite instability (MSI): 10 of the 14 (71.4%) MSI-positive tumors showed hypermethylation, whereas 28 of 94 (29.8%) the MSI-negative tumors were hypermethylated at the hMLH1 promoter region, Hypermethylation of the hMLH1 gene promoter was significantly inversely correlated with mutation of the p53 gene. CONCLUSION: These results suggest that cigarette smoking and alcohol consumption may influence the development of hMLH1-positive gastric cancer. Most dietary factors and polymorphisms of GSTM1, GSTT1, CYP1A1, CYP2E1, ALDH2, and L-myc genes are not independent risk factors for gastric cancer with hypermethylation of the hMLH1 promoter. These data also suggest that there could be two or more different molecular pathways in the development of gastric cancer, perhaps involving tumor suppression mechanisms or DNA mismatch repair.     

LKB1和血管内皮生长因子在胃癌组织中的表达及其临床意义

目的探讨LKB1和血管内皮生长因子(VEGF)在胃癌中的表达及临床意义。方法采用免疫组织化学(SP)法检测115例胃癌组织和20例胃正常组织中LKB1和VEGF的表达,并探讨其与胃癌分期、淋巴结转移、Lauren's分型及预后的关系。结果 LKB1在胃癌组织中的阳性率为20.9%,低于正常胃组织中的95.0%(P0.01);VEGF在胃癌组织中的阳性率为64.3%,高于正常胃组织中的5.0%(P0.01)。LKB1在胃癌组织中的低表达与胃癌的TNM分期、淋巴结转移、Lauren's分型及预后有关(P0.05);VEGF在胃癌中的表达与淋巴结转移、远处转移、TNM分期及预后相关(P0.05)。结论 LKB1的低表达与胃癌的发生、发展有关,对胃癌恶性生物学行为的评估及预后判断具有重要的指导意义。     

Promoter hypermethylation of CDH1, FHIT, MTAP and PLAGL1 in gastric adenocarcinoma in individuals from Northern Brazil

AIM: To evaluate the methylation status of CDH1, FHIT, MTAP and PLAGL1 promoters and the association of these findings with clinico-pathological characteristics. METHODS: Methylation-specific PCR (MSP) assay was performed in 13 nonneoplastic gastric adenocarcinoma, 30 intestinal-type gastric adenocarcinoma and 35 diffuse- type gastric adenocarcinoma samples from individuals in Northern Brazil. Statistical analyses were performed using the chi-square or Fisher’s exact test to assess associations between methylation status and clinico- pathological characteristics. RESULTS: Hypermethylation frequencies of CDH1, FHIT, MTAP and PLAGL1 promoter were 98.7%, 53.9%, 23.1% and 29.5%, respectively. Hypermethylation of three or four genes revealed a significant association with diffuse-type gastric cancer compared with nonneoplastic cancer. A higher hypermethylation frequency wassignificantly associated with H pylori infection in gastric cancers, especially with diffuse-type. Cancer samples without lymph node metastasis showed a higher FHIT hypermethylation frequency. MTAP hypermethylation was associated with H pylori in gastric cancer samples, as well as with diffuse-type compared with intestinal-type. In diffuse-type, MTAP hypermethylation was associated with female gender. CONCLUSION: Our findings show differential gene methylation in tumoral tissue, which allows us to conclude that hypermethylation is associated with gastric carcinogenesis. MTAP promoter hypermethylation can be characterized as a marker of diffuse-type gastric cancer, especially in women and may help in diagnosis, prognosis and therapies. The H pylori infectious agent was present in 44.9% of the samples. This infection may be correlated with the carcinogenic process through the gene promoter hypermethylation, especially the MTAP promoter in diffuse-type. A higher H pylori infection in diffuse-type may be due to greater genetic predisposition.     

Pin1和β-连环素在胃癌组织中的表达及其临床意义

目的探讨肽酰脯氨酰异构酶1（Pin1）与β-连环素在胃癌发生、发展中的作用。方法应用免疫组化SP技术对50例胃癌组织（胃癌组）及30例正常胃组织（对照组）中Pinl、β-连环素表达进行检测,分析两指标间相关性及与胃癌临床病理学特征的关系。结果胃癌组及对照组Pin1表达阳性率分别为24．0％（12／50）、0,B．连环素异常表达率分别为62．0％（31／50）、23．3％（7／30）,P均〈0．05;Pin1与β-连环素在胃癌组织中的表达密切相关（r=0．51,P〈0．01）;Pin1及β-连环素表达与胃癌病理分化程度、临床分期、淋巴结转移有关（P〈0．05）。结论Pin1和β-连环素异常表达可能在胃癌发生、发展中起重要作用,可作为指导肿瘤治疗及判断转移、预后等的参考指标之一。     

LOX、VEGF在胃癌进展中的作用关系

目的探讨赖氨酰氧化酶(lysyl oxidase,LOX)、血管内皮因子(vascular endothelial growth factor,VEGF)在胃癌进展中的作用关系。方法收集手术切除的新鲜胃癌组织65例,采用Western blotting方法检测胃癌组织中的LOX、VEGF蛋白表达,并比较二者在T1T2与T3T4胃癌组织、有无淋巴结转移胃癌组织中的关系。结果 (1)LOX在T3T4胃癌中的相对表达量为0.6003±0.1279,在T1T2胃癌中的相对表达量为0.4278±0.1437,差异有统计学意义(P0.05);(2)VEGF在T3T4胃癌中的相对表达量为0.6975±0.1639,在T1T2胃癌中的相对表达量为0.4263±0.1128,差异有统计学意义(P0.05);(3)LOX在伴有淋巴结转移的胃癌中的相对表达量为0.6827±0.1987,在无淋巴结转移的胃癌中的相对表达量为0.4235±0.1763,差异有统计学意义(P0.05);(4)VEGF在伴有淋巴结转移的胃癌中的相对表达量为0.6769±0.1659,在无淋巴结转移的胃癌中的相对表达量为0.4128±0.1471,差异有统计学意义(P0.05);(5)在T1T2和T3T4胃癌组织中,LOX与VEGF的表达水平呈正相关(r=0.735,P0.05),在有淋巴结转移和无淋巴结转移的胃癌组织中,LOX与VEGF的表达水平也呈正相关(r=0.914,P0.05)。结论 T3T4胃癌中LOX与VEGF的表达水平明显高于T1T2胃癌,在有淋巴结转移的胃癌组织中,LOX与VEGF的表达水平明显高于无淋巴结转移的胃癌组织中,且LOX与VEGF表达呈正相关;LOX与VEGF在胃癌的进展中有促进作用,并且相互协同。     

代谢酶基因GSTM1和广西人群胃癌遗传易感性的关系

目的探讨代谢酶基因GSTM1多态性与广西地区人群胃癌遗传易感性之间的相关性。方法采用PCR技术检测广西地区121例胃癌患者和138例健康人的GSTM1基因多态性的分布频率,分析其与广西地区胃癌遗传易感性之间的相关性以及与吸烟、饮酒在胃癌易感性中的交互作用。结果胃癌组GSTM1（-）基因型频率（54．5％）显著高于对照组（39．1％）（X^2=6．140,P=0．013）。携带GSTM1（-）基因型的个体患胃癌的风险是携带GSTM1（＋）基因型个体的2．13倍（95％CI=1．079-1．831,P=0．013）。在吸烟者中,携带GSTM1（-）基因型的个体较携带GSTM1（＋）基因型的个体患胃癌的风险明显增加（OR=3．247,95％CI=1．067—2．328,P=0．015）。其增加程度远远高于总的胃癌风险（OR=2．129）。在饮酒者中,携带GSTM1（-）基因型的个体较携带GSTM1（＋）基因型的个体患胃癌的风险亦明显增加（OR=3．117,95％CI=1．020—2．863,P=0．033）。其增加程度远远高于总的胃癌风险（OR=2．129）。结论GSTM1（-）基因型显著增加广西地区人群患胃癌的风险,且显著增加吸烟、饮酒者患胃癌的风险。     

载脂蛋白B基因EcoRI、XbaI及载脂蛋白AI基因-75 bp、＋83 bp位点多态性与冠心病的关系

目的 分析载脂蛋白B（apoB）基因EcoRI、XbaI位点和载脂蛋白AI（apoAl）基因-75 bp、＋83 bp位点多态性与新疆石河子地区汉族人冠心病的关系.方法 采用聚合酶链式反应-限制性片段长度多态性分析法检测204例冠心病患者和132例正常对照者的apoB基因EcoRI、XbaI位点和apoAI基因-75 bp、＋83 bp位点多态性.结果 （1）冠心病组和对照组apoB基因EcoRl、Xbal位点和apoAI基因-75 bp、＋83 bp位点基因型及等位基因频率与新疆石河子地区汉族人冠心病发病无关.（2）冠心病组和对照组各基因型组合的总体分布不同（Х^2=23.497,P=0.024）,E^＋＋/X^＋-/M1^＋-/M2^＋＋及E^＋-/X1^--/M1^＋＋/M2^＋＋基因型组合频率在冠心病组和对照组的比值（9.3% vs 3%）比较差异有显著性（P＜0.05）.（3）冠心病组中E^＋＋/X^＋-/M1^＋-/M2^＋- 基因型组合的患者 apoB 水平高于冠心病组和对照组平均水平（P均＜0.01）,apoAI/apoB水平低于冠心病组或对照组平均水平（P均＜0.01）;冠心病组E^＋-/X^--/M1^＋-/M2^＋＋ 基因型组合的患者apoB水平高于冠心病组和对照组平均水平（P均＜0.05）,apoAI/apoB水平低于冠心病组或对照组平均水平（P均〈0.05）,且其TG、LDL-C高于对照组（P均〈0.05）.结论 apoB 基因EcoRl、Xbal位点和apoAI基因-75 bp、＋83 bp位点基因型联合中,E^＋＋/X^＋-/M1^＋-/M2^＋＋ 及 E^＋--/X^--/M1^＋-/M2^＋＋ 与新疆石河子地区汉族人冠心病相关,其中的机制可能与基因变异引起apoB、apoAI/apoB的变化继而引起血脂变化等有关.