非小细胞肺癌中DPC4基因的表达与微血管形成的关系

目的：探讨DPC4（deleted in pancreatic carcinoma locus4，DPC4）基因在非小细胞肺癌（NSCLC）中的表达及其与微血管形成的关系。方法：利用免疫组织化学S-P法检测52例NSCLC组织、19例相应的癌旁正常肺组织中DPC4、VEGF的表达，用CD34标记血管内皮细胞并计算微血管密度MVD值。结果：DPC4在肺癌原发灶中的阳性表达率为63．5％（33／52），与癌旁正常肺组织中的阳性表达率89．5％（17／19）相比，DPC4阳性表达水平显著降低（P〈0．05）；DPC4与组织学类型、肿瘤细胞分化程度无关（P〉0．05），但与淋巴结转移显著相关（P〈0．05）。52例NSCLC中，DPC4的表达与VEGF、MVD值均呈负相关（r=-0．303，P=0．020）。结论：DPC4的低表达可能是肺癌发生过程的早期事件，可促进肺癌的淋巴结转移，并可通过直接或间接的作用促进肺癌血管生成。     

DPC4基因在胰腺癌中的改变

目的 研究DPC4（deleted in pancreatic cancer locus4)基因在胰腺癌中的改变。方法 用多聚酶链反应－单链构象多态性分析（PCR－SSCP）银染技术及PCR产物直接测序法检测胰腺癌细胞系P1、P2、P3、P4、P7、11例新鲜冷冻胰腺癌组织中DPC4基因第1、2、3、4、8、11外显子的缺失和突变。结果 5株人胰腺癌细胞系中,3株（P1、P2、P3）存在DPC4基因突变,DPC4基因改变率为3／5。11例新鲜冷冻胰腺癌细胞中,3例有DPC4基因的纯合性缺失,2例有基因突变,DPC4基因改变率为5／11（45．5％）。结论DPC4作为一种抑癌基因,其改变在胰腺癌的形成中可能起重要作用。     

胃癌MAGE-1基因启动子 B′B区去甲基化状态的研究

目的: 探讨胃癌组织中 MAGE-1基因启动子 B′B区去甲基化状态及其与病理分级及临床分期的关系.方法: 取胃癌组织标本40例,另外取同患者相应的癌旁组织40例作为对照.采用分子生物学技术-甲基化敏感性内切酶酶切及 PCR扩增技术,研究了胃癌组织中MAGE-1启动子 B′B区的去甲基化状态.结果: 在所检测的胃癌组织标本中 MAGE-1基因启动子 B′B区去甲基化的发生率为25%(10/40).而在癌旁组织中发生率为0,两者发生率的差别具有显著的统计学意义(P＜0.01).在低分化腺癌中 MAGE-1基因的 B′B区去甲化发生率为50%(6/12),中分化腺癌中发生率为18.7%(3/16),高分化腺癌中发生率为8.3( 1/11).其发生率的差异有统计学意义(P<0.05).在早期胃癌组织中 B′B区的去甲基化的发生率为16.7%,在晚期胃癌组织中发生率为28.6%(P<0.05),差别有统计学意义.结论: 胃癌组织中 MAGE-1基因启动子的 B′B区存在去甲基化.该区的去甲基化发生率与胃癌组织的病理分级以及与临床分期有关.     

胃癌中E-cadherin和DAPK基因启动子异常甲基化的研究

目的:检测胃癌中死亡相关蛋白激酶(death-associated protein kinase,DAPK)基因和上皮钙粘蛋白(epithelial cadherin,E-cadherin)基因启动子区CpG岛甲基化状态,并探讨两个基因甲基化改变的特点及其与临床病理特征、患者一般资料之间的关系.方法:采用目前常用的甲基化特异性PCR(Methylation-specific PCR.MSP)方法检测4l例胃癌组织和20例正常对照组织中DAPK、E-cadherin基因启动子区甲基化状态并进行统计分析.结果:41例胃癌组织中DAPK、E-cadherin基因启动子区甲基化阳性率分别为68.3%(28/41)和46.3%(19/41),20例正常时照组织中未检测到DAPK、E-cadherin基因启动子区发生甲基化,两个基因在胃癌组织中的甲基化率明显高于正常对照组织(P<0.05),但DAPK和E-cadherin基因启动子甲基化在胃癌的发生中无协同性(相关性和一致性).胃癌组织中一个基因发生甲基化的检出率为78.0%(32/41);胃癌组织中DAPK基因启动子区甲基化与淋巴结转移、分化程度相关(P<0.05),而E-cadherin基因启动子区甲基化则与淋巴结转移和浸润深度有相关性(P<0.05).两个基因启动子区异常甲基化与被检查者肿瘤的大小、肿瘤的部位等临床病理特征以及被检者的性别、年龄不具有相关性.结论:DAPK、E-eadherin基因启动子区甲基化是胃癌发生、发展过程中的频发事件,通过检测胃粘膜组织中两个基因启动子区甲基化状况,可能会对胃癌的早期诊断及判断预后提供一定的参考价值;联合检测两个基因甲基化状态优于各单个基因检测.     

大肠癌中DPC4蛋白表达及与临床病理特征的关系

[目的]探讨大肠癌组织中DPC4蛋白的表达及其与患者临床病理特征的关系.[方法]免疫组化Elivison二步法检测60例大肠癌手术切除标本中DPC4蛋白的表达,并探讨其与患者组织学类型、浸润深度、淋巴结转移和远处转移等临床病理特征的关系.并取40例癌旁正常大肠组织作对照.[结果] DPC4蛋白主要在大肠癌和癌旁正常大肠组织的胞浆表达,呈棕黄色细颗粒.60例大肠癌标本中DPC4的阳性表达为21例(35.0％),其中强阳性为4例(6.7％).40例癌旁正常大肠组织中DPC4蛋白表达均为阳性,其中强阳性34例(85.0％).大肠癌组织中DPC4蛋白阳性表达率明显低于癌旁正常大肠组织(x2=42.62,P＜0.01).大肠癌组织中DPC4蛋白表达水平随组织分化程度的增加而增加(P＜0.01),随原发病灶的浸润深度增加、淋巴结转移和远处转移的出现而下降(P＜0.01).[结论]且DPC4蛋白表达降低或缺失在大肠癌的发生发展过程起重要作用,有望成为大肠癌基因诊断和治疗的新靶点.     

DPC4 基因在肺癌中的表达及其与微血管形成和凋亡的关系

 目的 探讨DPC4（deleted in pancreatic carcinoma locus 4，DPC4）基因在非小细胞肺癌（nonsmall cell lung carcinoma，NSCLC）中的表达及其与微血管形成和凋亡的关系。方法 利用免疫组织化学S-P法检测52例NSCLC组织、19例相应的癌旁正常肺组织中DPC4、VEGF的表达，用CD34标记血管内皮细胞并计算微血管密度MVD值，应用TUNEL技术对细胞凋亡情况进行了检测并计算凋亡指数。结果 DPC4在肺癌原发灶中的阳性表达率为63．5％（33／52），与癌旁正常肺组织中的阳性表达率89．5％（17／19）相比，DPC4阳性表达水平显著降低（P〈0．05）DPC4与组织学类型、肿瘤细胞分化程度无关（P〉0．05），但与淋巴结转移显著相关（P〈0．05）。52例NSCLC中，DPC4的表达与VEGF、MVD值均呈负相关（r=-0．303，P=0．020）。DPC4阳性组凋亡指数（apoptotic index，AI）值明显高于DPC4阴性组（P〈0．05）。结论 DPC4的低表达可能是肺癌发生过程的早期事件，并可通过直接或间接的作用促进肺癌血管生成，从而促进肺癌的淋巴结转移，DPC4的高表达可能促进细胞的凋亡。     

胃癌Kai-1基因缺失与突变的研究

目的：探讨Kai-1基因的缺失与突变在胃癌演进与转移中的意义。方法：提取30例胃癌患者的肿瘤组织（16例无淋巴转移,14例有淋巴转移）,30例癌旁正常组织的RNA,RT—PCR扩增,电泳检测,测序验证Kai-1基因的缺失情况;并提取发生缺失的肿瘤组织的DNA,PCR扩增,测序探讨Kai-1基因的突变情况。结果：30例组织标本中12例出现Kai-1基因exon9缺失（10例杂合缺失,2例纯合缺失）,30例癌旁正常组织中有5例出现Kai-1基因exon9缺失（5例杂合缺失）;在胃癌组织中Kai-1基因缺失频率显著高于在癌旁正常组织（P〈0．05）;在有淋巴转移的胃癌组织中,缺失的频率明显高于无淋巴转移的胃癌组织（P〈0．05）,在胃癌中晚期（Ⅲ-Ⅳ期）明显高于早期（I-Ⅱ期）（P〈0．05）,而Kai-1基因的缺失频率与胃癌患者的年龄、性别、组织学类型以及分化程度无关（P〉0．05）。结论：Kai-1基因缺失与突变可能与胃癌演进、转移有关,检测其缺失或突变可作为判断胃癌的演进与转移的客观临床指标。     

胃癌Kai-1基因缺失与突变的研究

目的:探讨Kai-1基因的缺失与突变在胃癌演进与转移中的意义.方法:提取30例胃癌患者的肿瘤组织(16例无淋巴转移,14例有淋巴转移),30例癌旁正常组织的RNA,RT-PCR扩增,电泳检测,测序验证Kai-1基因的缺失情况;并提取发生缺失的肿瘤组织的DNA,PCR扩增,测序探讨Kai-1基因的突变情况.结果:30例组织标本中12例出现Kai-1基因exon9缺失(10例杂合缺失,2例纯合缺失),30例癌旁正常组织中有5例出现Kai-1基因exon9缺失(5例杂合缺失);在胃癌组织中Kai-1基因缺失频率显著高于在癌旁正常组织(P<0.05);在有淋巴转移的胃癌组织中,缺失的频率明显高于无淋巴转移的胃癌组织(P<0.05),在胃癌中晚期(Ⅲ-Ⅳ期)明显高于早期(Ⅰ-Ⅱ期)(P<0.05),而Kai-1基因的缺失频率与胃癌患者的年龄、性别、组织学类型以及分化程度无关 (P>0.05).结论:Kai-1基因缺失与突变可能与胃癌演进、转移有关,检测其缺失或突变可作为判断胃癌的演进与转移的客观临床指标.     

Analysis of the DPC4 Gene in Gastric Carcinoma

Allelic loss on chromosome 18q is involved in the progression of gastric carcinoma. Recently, DPC4 (deleted in pancreatic carcinoma, locus 4), a candidate tumor suppressor gene, has been localized at 18q21.1. This gene is inactivated in nearly one half of pancreatic carcinomas. We tested for DPC4 gene mutations and allelic status at 18q21 in 30 primary gastric carcinomas and 5 gastric carcinoma cell lines. Polymerase chain reaction single-strand conformation polymorphism and sequencing analyses revealed no DPC4 mutations in any of the primary tumors or cell lines. Homozygous deletion ofDPC4 was observed in only 1 (MKN-45) of the 5 (20%) cell lines. This suggests that the target gene for loss on 18q is not DPC4. The true tumor suppressor gene, encoded near DPC4 , has yet to be identified.     

Expression of DPC4/Smad4 gene in stone-containing intrahepatic bile duct

BACKGROUND AND OBJECTIVES: Hepatolithiasis is etiologically related to cholangiocarcinoma. We underwent this study with an attempt to examine the expression of DPC4/Smad4 gene in stone-containing intrahepatic bile ducts (IHD) and intrahepatic cholangiocarcinoma (ICC). PATIENTS AND METHODS: The immunohistochemical method and RT-PCR analysis were used to study the expression of DPC4/Smad4 gene in normal IHD, stone-containing IHD, and ICC. All the specimens were from hepatic resection. RESULTS: The immunohistochemical study showed that all specimens from 24 normal IHD had marked expression of DPC4/Smad4 gene, while there was 4.4% (2/46) and 33.3% (3/9) loss of DPC4/Smad4 expression in stone-containing IHD and ICC, respectively. Among the specimens of stone-containing IHD, all the hyperplastic epithelial cells showed normal expression of DPC4/Smad4 gene while dysplastic epithelial cells showed 20% (2/10) loss expression of DPC4/Smad4. The RT-PCR analysis showed that the normal IHD had the highest content of DPC4/Smad4 mRNA, which was threefold and sixfold higher than that of stone-containing IHD and ICC, respectively. CONCLUSION: Loss expression of DPC4/Smad4 gene was found both in stone-containing IHD and ICC. Dysplastic epithelium of stone-containing IHD had higher potential for malignant transformation.     

DPC4蛋白在胆道恶性肿瘤中的缺失表达

Objective To clarify the relationship between loss of expression of DPC4 proteins and pathogenesis of biliary tract carcinoma. Methods 71 primary biliary tract carcinomas (BTCa), including 38 common bile duct (CBD) carcinomas, 18 gallbladder carcinomas, and 15 hilar bile ducts (HBD) carcinomas were examined by immunohistochemical staining. In addition, the CBD carcinomas were divided into two groups, a tumor group with metastasis (M+ group, 27 cases) and a tumor group without metastasis (M− group, 11 cases). Results The frequency of loss expression of DPC4 protein was 32.8% in BTCa, 47.3% in CBD carcinoma, 11% in gallbladder carcinoma and 13% in HBD carcinoma. A comparison of the frequency of loss expression of DPC4 showed significantly statistical difference in the CBD carcinoma versus gallbladder carcinoma and HBD carcinoma (P<0.01). The frequency of loss expression of DPC4 was 48.1% in the M⁺ group and 45.4% in the M⁻ group. There was no significantly statistical difference between them (P>0.05). Conclusion There is a close relationship between the pathogenesis of BTCa and inactivation of DPC4 with different frequencies of DPC4 gene alteration in various locations of the biliary tract, but inactivation of DPC4 is not related with tumor metastasis in BTCa.     

Hypermethylation of the TSLC1 Gene Promoter in Primary Gastric Cancers and Gastric Cancer Cell Lines

The TSLC1 (tumor suppressor in lung cancer–1) gene is a novel tumor suppressor gene on chromosomal region 11q23.2, and is frequently inactivated by concordant promoter hypermethylation and loss of heterozygosity (LOH) in non-small cell lung cancer (NSCLC). Because LOH on 11q has also been observed frequently in other human neoplasms including gastric cancer, we investigated the promoter methylation status of TSLC1 in 10 gastric cancer cell lines and 97 primary gastric cancers, as well as the corresponding non-cancerous gastric tissues, by bisulfite-SSCP analysis followed by direct sequencing. Allelic status of the TSLC1 gene was also investigated in these cell lines and primary gastric cancers. The TSLC1 promoter was methylated in two gastric cancer cell lines, KATO-III and ECC10, and in 15 out of 97 (16%) primary gastric cancers. It was not methylated in non-cancerous gastric tissues, suggesting that this hypermethylation is a cancer-specific alteration. KATO-III and ECC10 cells retained two alleles of TSLC1 , both of which showed hypermethylation, associated with complete loss of gene expression. Most of the primary gastric cancers with promoter methylation also retained heterozygosity at the TSLC1 locus on 11q23.2. These data indicate that bi-allelic hypermethylation of the TSLC1 promoter and resulting gene silencing occur in a subset of primary gastric cancers.     

沉默ABCC4基因逆转人胃癌多药耐药的研究

目的 探讨胃癌耐药复发相关基因ABCC4在胃癌耐药复发中的分子机制。方法 采用免疫组织化学、Western blot、RT-PCR、流式细胞检测胃癌组织及胃癌耐药细胞中ABCC4的表达情况,利用RNA干扰技术下调ABCC4基因在胃癌耐药细胞中的表达水平。结果 ABCC4基因在多种胃癌细胞中高表达,尤其是在胃癌耐药细胞中表达增加更为显著,但在正常胃黏膜细胞中极低表达或表达缺失。RNA干扰下调ABCC4基因可导致胃癌耐药细胞发生凋亡,并且细胞周期被阻滞在G1期以内。5-Fu可以显著抑制ABCC4沉默后肿瘤细胞增殖,同时,也能明显抑制ABCC4沉默后裸鼠体内肿瘤生长。结论 ABCC4基因过度表达于胃癌耐药细胞中,下调ABCC4基因表达可抑制胃癌多药耐药细胞增殖,并且可增强其对化疗药物的敏感度。     

KLF4蛋白在胃癌组织中的表达及临床意义

背景与目的:KLF4(Krllppel-like factor 4)是一种在多种组织中广泛表达的锌指转录因子,在许多不同的生理活动中具有重要作用,研究表明KLF4基因与多种肿瘤的发生发展有关,我们通过检测胃癌组织中KLF4蛋白的表达,以探讨KLF4蛋白与胃癌I临床病理间的关系.材料与方法:采用免疫组化SP法,分别检测102例胃癌手术标本的癌组织,癌旁组织及同期收集的正常胃组织标本中KLF4表达的情况.结果:KLF4蛋白表达位于细胞质及细胞核,在癌旁组织或正常胃组织呈强阳性表达,而在胃上皮内瘤变中表达较弱,胃癌组织中KLF4蛋白几乎未见表达.KLF4表达随胃癌分期的变化(I~Iv)其表达依次下降(P<0.05).有淋巴结转移组KLF4蛋白阳性表达率为63.3%,无淋巴结转移组的阳性表达率为78.6%.其差异有统计学意义(P<0.05).结论:KLF4蛋白在胃癌中表达降低,并与胃癌发生、分期及淋巴结转移有关,可作为胃癌预后的判断指标及潜在的治疗靶点.