RASSF1A和SKP2在胃癌中的表达及与幽门螺杆菌L型感染关系的研究

目的研究幽门螺杆菌L型(Helicobacter pyloriL-form,H.pylori-L型)感染,Ras相关区域家族1A基因(RASSF1A)和细胞S期激酶相关蛋白2(Skp2)在胃癌发生、发展中的作用及相互关系。方法应用革兰染色和免疫组织化学SP法检测50例胃癌组织及20例癌旁正常组织中的H.pylori-L型感染情况;同时应用逆转录聚合酶链式反应(RT-PCR)和免疫组织化学SP法检测上述组织中癌基因skp2和抑癌基因RASSF1A的表达。结果 50例胃癌组织标本中免疫组化及革兰染色H.pylori-L型同时阳性的病例有30例,胃癌组织和癌旁正常组织中H.pylo-ri-L型阳性率分别为60.0%和20.0%,2组之间差异有统计学意义(P<0.05)。胃癌组织中Skp2表达阳性率明显高于对照组(P<0.01);而RASSF1A表达阳性率明显低于对照组(P<0.01);H.pylori-L型阳性组的Skp2表达阳性率高于H.pylori-L型阴性组(P<0.05);H.pylori-L型阳性与Skp2的表达阳性呈正相关关系;RASSF1A的表达与H.pylori-L型阳性呈负相关关系。结论 H.pylori-L型感染在胃癌的发生发展过程中起重要的作用,其促进胃癌发生、发展的机制可能涉及上调Skp2的表达和下调RASSF1A的表达。     

EB病毒感染与胃癌患者临床病理特征相关性的Meta分析

EB病毒(EPstein-Barr virus, EBV)感染与多种恶性肿瘤的发生相关. 大约10%的胃癌组织细胞中可以检测到EB病毒编码的小RNA(EBERs), 表明EBV感染与部分胃癌的发生相关. 为研究EBV感染与胃癌临床病理特征的相关性, 本研究汇总了EBV相关胃癌的研究论文, 对采用原位杂交方法检测EBV的22篇论文进行了Meta分析. 22篇入选的论文中收集的胃癌病例5475例, 检测到EBV阳性病例411例, EBV阳性率为7.5%. 在EBV阳性胃癌中, 男性检出率为11.1%, 女性检出率为3.0%, 男性检出率相当于女性检出率3倍多; EBV阳性胃癌与阴性胃癌相比具有较少的淋巴结转移; EBV阳性胃癌与癌组织发生部位相关, 并且残胃癌中EBV感染率较高. 依据组织学分型, EBV阳性胃癌弥漫型为8.1%, 肠型为8.0%. 统计分析显示, EBV感染与组织学分型无显著相关性(P＞0.05); 被检标本类型包括存档蜡块和新鲜手术切除组织标本: EBV阳性率分别为7.9%, 6.5%. 统计分析表明, EBV相关胃癌与标本类型无显著相关性(P＞0.05); 在地域分布方面, EBV阳性胃癌检出率美洲为9.4%, 亚洲为6.1%, 欧洲为9.1%, 统计分析显示, EBV相关胃癌与地域分布显著相关(P＜0.05). Meta分析表明, EBV感染仅发生在胃癌组织细胞中, 并且与患者性别、淋巴结转移、肿瘤组织发生部位及地域分布显著相关(P＜0.05), 与患者肿瘤组织学分型、标本类型无显著相关性(P＞0.05). 结果提示, EBV阳性胃癌具有独特的临床病理学特征.     

胃癌组织中MMP-7和TIMP-1的表达及意义

目的:探讨基质金属蛋白酶-7(MMP-7)及其组织抑制剂-1(TIMP-1)与胃癌发生发展的关系.方法:采用免疫组化技术检测46例胃癌组织和相应癌旁组织中MMP-7和TIMP-1的表达,结合病人临床病理资料进行综合分析.结果:胃癌组织中MMP-7阳性表达率(60.87%)显著高于相应癌旁组织,差异有统计学意义(P<0.05);其表达与淋巴结转移(P<0.05)相关.胃癌组织中TIMP-1的阳性表达率(93.48%)明显高于相应癌旁组织(63.04%),差异有统计学意义(P<0.05);其表达与淋巴结转移相关(P<0.05).结论:MMP-7与胃癌的侵袭转移有关,TIMP-1有可能成为评价胃癌恶性生物学行为的指标.     

Mina53在胃癌组织中的表达及临床意义

目的:探讨mina53基因在胃癌组织中的表达及其与临床分期的相关性.方法:分别应用RT-PCR和免疫组化技术,检测71例胃癌患者组织标本以及20例癌旁组织中mina53基因和蛋白的表达水平,并分析其与胃癌临床分期的相关性.结果:(1)RT-PCR结果显示20例癌旁组织中仅2例mina53基因呈弱阳性表达,阳性率为10.00％;71例胃癌组织标本中有43例mina53基因表达阳性,阳性率为60.56％ (P＜0.05);其中Ⅰ、Ⅱ、Ⅲ、Ⅳ期胃癌组织标本中的阳性比例分别为11/23、15/29、12/14及5/5(P＜0.05).(2)免疫组化结果显示20例癌旁组织中仅3例mina53蛋白呈弱阳性表达,阳性率为15.00％;71例胃癌组织标本中有35例mina53蛋白表达阳性,阳性率为49.30％(P＜0.05);其中Ⅰ、Ⅱ、Ⅲ、Ⅳ期胃癌组织标本中的阳性比例分别为7/23、13/29、11/14及4/5 (P＜0.05).结论:与癌旁组织相比,mina53在胃癌中的基因和蛋白水平存在高表达,并且随肿瘤分期的进展而表达量增高,检测mina53表达水平有助于胃癌早期诊断和预测肿瘤的侵袭程度.     

MDM2在胃癌组织中的表达及与Hp-L型感染关系的研究

目的研究MDM2在胃癌组织中的表达意义及其与幽门螺杆菌L型(Helicobacter pylori-L,Hp-L)感染在胃癌发生中的关系。方法 (1)应用革兰染色法和免疫组化学法检测100例胃癌及对应的40例癌旁正常胃黏膜组织(对照组)中Hp-L型感染和MDM2蛋白的表达情况;(2)应用逆转录多聚酶链反应(RT-PCR)方法检测MDM2的mRNA在30例新鲜胃癌组织及其对应的癌旁正常胃粘膜组织(对照组)中的表达情况。结果 100例胃癌组织及对应的40例癌旁正常胃粘膜组织中MDM2阳性表达率为71.0%(71/100)和42.5%(17/40),可见MDM2在胃癌组织中高表达和在非胃癌组中低表达具有统计学意义(P0.05),且MDM2表达水平升高与肿瘤大小、浸润深度、淋巴结转移和TNM分期有关(P0.05),与性别、年龄无关(P0.05);RT-PCR显示,肿瘤组织MDM2的表达明显高于远端正常胃黏膜对照组织的表达量且差异明显(P0.01)。革兰染色和免疫组化两种方法检测Hp-L型结果具有一致性(P0.05),胃癌组织中Hp-L型感染阳性组的MDM2表达阳性率高于Hp-L型阴性组(P0.05),且Hp-L型阳性率和MDM2蛋白表达呈正相关(r=0.447,P0.05)。结论 MDM2蛋白在胃癌中呈高表达,且与胃癌的浸润、转移有关,其机制可能与Hp-L型感染有关。     

幽门螺杆菌感染与胃癌共刺激分子OX40和 OX40L表达的相关性

目的研究幽门螺杆菌(H.pylori)感染与胃癌共刺激分子OX40、OX40L表达的相关性。方法收集本院2017年1月至2019年1月进行胃癌手术的68例患者为研究对象。采用Giemsa染色和PCR方法检测胃癌组织H.pylori感染情况。应用免疫组织化学法检测胃癌和癌旁组织中共刺激分子OX40、OX40L的表达,并分析共刺激分子OX40、OX40L表达与胃癌组织H.pylori感染的相关性。分析OX40、OX40L表达与胃癌患者临床病理特征的关系。采用二元Logistic回归分析胃癌组织H.pylori感染的影响因素。结果胃癌组织中OX40、OX40L阳性表达率显著高于癌旁组织(均P0.05);Giemsa染色和PCR检测胃癌组织中H.pylori感染阳性率分别为86.76%(59/68)和91.18%(62/68)。H.pylori阳性胃癌组织中OX40、OX40L阳性表达率显著高于H.pylori阴性胃癌组织(均P0.05)。OX40、OX40L表达与胃癌患者肿瘤浸润深度、分化程度、T分期、淋巴结转移均无显著相关性(均P0.05),而与胃癌肿块大小相关(P0.05)。OX40、OX40L阳性表达是胃癌组织中H.pylori感染的危险因素。结论 H.pylori感染可能与胃癌组织中OX40、OX40L异常表达相关,可为探究H.pylori致癌机制提供一定参考。     

EB病毒阳性和阴性胃癌中视网膜母细胞瘤基因甲基化状态及其表达

目的:了解EB病毒(Epstein-Barr virus,EBV)相关胃癌(EBVaGC)和阴性胃癌(EBVnGC)组织中视网膜母细胞瘤(Rb)基因甲基化状态及蛋白表达,探讨EBV感染与Rb基因甲基化的关系.方法:采用甲基化特异性PCR(MSP)对各种临床病理指标匹配的23例EBVaGC和25例EBVnGC组织及相应癌旁组织中Rb基因启动子区域的甲基化状态进行检测,并采用免疫组化技术检测两种胃癌组织中Rb蛋白的表达.结果:胃癌与相应癌旁组织中Rb基因启动子区的甲基化率分别为64.6%(31/48)和39.6%(19/48),差异有显著性(P<0.05);EBVaGC组织中Rb基因启动子区的甲基化率为82.6%(19/23),高于EBVnGC中的检出率(48.0%,12/25),差异有显著性(P<0.05);EBVaGC和EBVnGC组织中Rb蛋白的表达率分别为52.2%(12/23)和72.0%(18/25),差异无显著性(P□0.05);胃癌组织中Rb启动子基因甲基化与蛋白表达无明显负相关.结论:Rb异常甲基化在胃癌细胞中较常见,EBV可以诱导Rb基因甲基化,影响其基因表达而参与EBVaGC的发生.     

幽门螺旋杆菌感染与胃癌中Shh和C-myc表达的关系

为了探讨胃癌中幽门螺旋杆菌(Hp)感染和Sonic Hedgehog(Shh)、C-myc表达,它们之间的相关性以及胃癌发生的可能机制,采用免疫组化法检测89例胃癌组织及20例正常胃上皮组织中Shh及C-myc的表达。并采用快速尿素酶试验,组织病理学检测两种方法检查Hp。实验结果显示,胃癌组织Shh的表达要明显高于正常上皮组织,二者之间有显著差异(P<0.05);胃癌组织C-myc的表达水平也高于正常胃上皮组织,二者之间有显著差异(P<0.05);Hp阳性的C-myc阳性表达率明显高于Hp阴性,二者之间有显著差异(P<0.05);Shh表达阳性率在Hp阳性和阴性胃癌中无显著差异(P>0.05)。结果提示,胃癌的发生与癌基因Shh及C-myc的过度表达有关,Hp感染的致癌机制中可能有癌基因C-myc参与。     

胃癌组织中细胞凋亡与c-myc和Ki-67异常表达的实验研究

目的:检测胃癌以及相应癌旁组织中细胞凋亡与c-myc及Ki-67蛋白的表达,探讨它们在胃癌发生发展中的作用.方法:选取58例胃癌和相应癌旁组织作为研究对象,采用脱氧核苷酸移换酶(TdT)介导的dUTP切口末端标记方法(TUNEL)检测细胞凋亡指数(AJ).免疫组化技术检测c-myc及Ki-67蛋白的表达.结果:胃癌组织及癌旁组织中细胞凋亡指数(AI)平均值分别为0.969±0.413和2.033±0.600,统计学分析表明:两组间AJ平均值差别有显著性(t=11.125,P<0.01).58例胃癌及癌旁组织中c-myc蛋白的阳性率分别为55.93%(33/58)和36.21%(21/58),两组比较有显著性差异(χ2=5.042,P<0.05);58例胃癌(GC)、16例伴癌前病变癌旁粘膜(MAWPL)、42例不伴癌前病变癌旁粘膜(MAWOPL)组织中Ki-67指数分别为35.716±15.091、31.817±10.332和12.44±10.912,统计学分析结果显示胃癌和MAWPL组织中Ki-67指数明显高于MAWOPL组织,差异有显著性(P<0.01).58例胃癌组织中c-myc阳性组KI平均值明显高于c-myc阴性组(t=3.364,P<0.01).结论:胃癌组织中存在c-myc基因的异常表达和Ki-67蛋白的过表达.c-myc阳性胃癌的Ⅺ平均值明显高于c-myc阴性胃癌,提示c-myc表达可以诱导肿瘤细胞活跃增殖.     

转录因子Ets-1与MMP-9在胃癌中的表达及临床意义

目的观察转录因子Ets-1和MMP-9在胃癌组织中的表达;探讨两者在胃癌浸润转移中的作用、相互关系及意义。方法采用免疫组织化学S-P法检测97例胃癌及癌旁组织、28例正常胃黏膜组织中Ets-1和MMP-9的表达。结果胃癌组织中Ets-1和MMP-9的阳性表达率分别为74.2%(72/97)、75.3%(73/97),均明显高于癌旁组织(40.2%、18.6%)及正常胃黏膜组织(17.9%、14.3%)(P0.01);而在癌旁组织及正常胃黏膜组织中两者的表达差异无显著性(P0.05)。Ets-1和MMP-9的阳性表达率在乳头状腺癌、管状腺癌及低分化腺癌与黏液癌之间差异有显著性(P0.01)。Ets-1和MMP-9的高表达与胃癌浸润深度、淋巴结转移及临床分期有关(P0.01),与性别、年龄、肿瘤大小及肿瘤位置均无关(P0.05)。Ets-1和MMP-9的表达成正相关(r=0.700,P0.01)。结论Ets-1和MMP-9高表达与胃癌的浸润、转移密切相关;通过上调MMP-9的表达,可能是Ets-1促进胃癌浸润转移的机制之一。     

CD21-Dependent Infection of an Epithelial Cell Line, 293, by Epstein-Barr Virus

Epstein-Barr virus (EBV) is invariably present in undifferentiated nasopharyngeal carcinomas, is found sporadically in other carcinomas, and replicates in the differentiated layer of the tongue epithelium in lesions of oral hairy leukoplakia. However, it is not clear how frequently or by what mechanism EBV infects epithelial cells normally. Here, we report that a human epithelial cell line, 293, can be stably infected by EBV that has been genetically marked with a selectable gene. We show that 293 cells express a relatively low level of CD21, that binding of fluorescein-labeled EBV to 293 cells can be detected, and that both the binding of virus to cells and infection can be blocked with antibodies specific for CD21. Two proteins known to form complexes with CD21 on the surface of lymphoid cells, CD35 and CD19, could not be detected at the surface of 293 cells. All infected clones of 293 cells exhibited tight latency with a pattern of gene expression similar to that of type II latency, but productive EBV replication and release of infectious virus could be induced inefficiently by forced expression of the lytic transactivators, R and Z. Low levels of mRNA specific for the transforming membrane protein of EBV, LMP-1, as well as for LMP-2, were detected; however, LMP-1 protein was either undetectable or near the limit of detection at less than 5% of the level typical of EBV-transformed B cells. A slight increase in expression of the receptor for epidermal growth factor, which can be induced in epithelial cells by LMP-1, was detected at the cell surface with two EBV-infected 293 cell clones. These results show that low levels of surface CD21 can support infection of an epithelial cell line by EBV. The results also raise the possibility that in a normal infection of epithelial cells by EBV, the LMP-1 protein is not expressed at levels that are high enough to be oncogenic and that there might be differences in the cells of EBV-associated epithelial cancers that have arisen to allow for elevated expression of LMP-1.     

Sequence variation of Epstein-Barr virus (EBV) BZLF1 gene in EBV-associated gastric carcinomas and nasopharyngeal carcinomas in Northern China

Epstein-Barr virus (EBV) BZLF1 gene can trigger EBV from latent infection to lytic replicative phase. The functions of BZLF1 are well known, while little is known about its gene polymorphism. In order to elucidate the sequence variations of BZLF1 and its association with malignancies, we analyzed BZLF1 gene in 24 EBV-associated gastric carcinomas, 41 nasopharyngeal carcinomas and 24 throat washing samples from healthy donors in Northern China using PCR-direct sequencing method. Three types and 8 subtypes of BZLF1 were identified. A dominant type BZLF1-A was found in 67 of 89 (75.3%) isolates. Type BZLF1-B was characterized by a common Ala deletion at residue 127, which was detected in 21 of 89 isolates (23.6%). Type BZLF1-C contained only one isolate (GC103), which had the same sequence with the prototype B95-8. Among 3 functional domains of BZLF1 protein, the transactivation domain had most mutations, followed by the bZIP domains (the DNA binding domain and dimerization domain). No prevalence of any subtypes or mutations in the functional domains among three specimen groups was found (P > 0.05). Our study indicates that BZLF1 subtypes and amino acid changes in functional domains are not preferentially associated with EBV-associated gastric carcinomas or nasopharyngeal carcinomas in Northern China. BZLF1 gene variations are geographically restricted rather than tumor-specific polymorphisms.     

The latent membrane protein 1 of Epstein-Barr virus establishes an antiviral state via induction of interferon-stimulated genes

Epstein-Barr virus (EBV) infection is associated with several human cancers. Latent membrane protein 1 (LMP-1) is one of the key viral proteins required for transformation of primary B cells in vitro and establishment of EBV latency. In this report, we show that LMP-1 is able to induce the expression of several interferon (IFN)-stimulated genes (ISGs) with antiviral properties such as 2'-5' oligoadenylate synthetase (OAS), stimulated trans-acting factor of 50 kDa (STAF-50), and ISG-15. LMP-1 inhibits vesicular stomatitis virus (VSV) replication at low multiplicity of infection (0.1 pfu/cell). The antiviral effect of LMP-1 is associated with the ability of LMP-1 to induce ISGs; an LMP-1 mutant that cannot induce ISGs fails to induce an antiviral state. High levels of ISGs are expressed in EBV latency cells in which LMP-1 is expressed. EBV latency cells have antiviral activity that inhibits replication of superinfecting VSV. The antiviral activity of LMP-1 is apparently not related to IFN production in our experimental systems. In addition, EBV latency is responsive to viral superinfection: LMP-1 is induced and EBV latency is disrupted by EBV lytic replication during VSV superinfection of EBV latency cells. These data suggest that LMP-1 has antiviral effect, which may be an intrinsic part of EBV latency program to assist the establishment and/or maintenance of EBV latency.     

Epstein-Barr Virus Infection in Chronically Inflamed Periapical Granulomas

Periapical granulomas are lesions around the apex of a tooth caused by a polymicrobial infection. Treatment with antibacterial agents is normally performed to eliminate bacteria from root canals; however, loss of the supporting alveolar bone is typically observed, and tooth extraction is often selected if root canal treatment does not work well. Therefore, bacteria and other microorganisms could be involved in this disease. To understand the pathogenesis of periapical granulomas more precisely, we focused on the association with Epstein-Barr virus (EBV) using surgically removed periapical granulomas (n = 32). EBV DNA was detected in 25 of 32 periapical granulomas (78.1%) by real-time PCR, and the median number of EBV DNA copies was approximately 8,688.01/μg total DNA. In contrast, EBV DNA was not detected in healthy gingival tissues (n = 10); the difference was statistically significant according to the Mann-Whitney U test (p = 0.0001). Paraffin sections were also analyzed by in situ hybridization to detect EBV-encoded small RNA (EBER)-expressing cells. EBER was detected in the cytoplasm and nuclei of B cells and plasma cells in six of nine periapical granulomas, but not in healthy gingival tissues. In addition, immunohistochemical analysis for latent membrane protein 1 (LMP-1) of EBV using serial tissue sections showed that LMP-1-expressing cells were localized to the same areas as EBER-expressing cells. These data suggest that B cells and plasma cells in inflamed granulomas are a major source of EBV infection, and that EBV could play a pivotal role in controlling immune cell responses in periapical granulomas.