食管鳞癌分泌素-3A1基因启动子甲基化异常

[目的]研究具有抗癌活性的细胞因子分泌素-3A1基因启动子超甲基化所至该基因表达抑制在我国食管鳞癌发生中的作用。[方法] 用RT-PCR 方法检测分泌素-3A1基因在12个食管鳞癌细胞系的表达,并用甲基化特异PCR技术（methylation specific PCR, MSP）检测上述细胞系及37例来自我国河南的原发性食管鳞癌标本分泌素-3A1基因启动子甲基化状态,通过5-aza-dc处理使培养细胞去甲基化,RT-PCR技术检测处理后该基因在Kyse30的重新表达。[结果] 该基因仅在Kyse410、Kyes520和TE8等3个细胞系有表达,5-aza-dc处理可使Kyse30重新表达分泌素-3A1。此外,在18/37（48%）例原发性食管鳞癌细胞有分泌素-3A1基因启动子区域的超甲基化。[结论] 启动子超甲基化造成分泌素-3A1基因在上述食管鳞癌细胞系表达抑制,原发性食管鳞癌细胞分泌素-3A1基因启动子超甲基化提示该基因表达抑制可能与食管鳞癌发生有关。     

食管癌的癌基因和肿瘤抑制基因研究进展

食管癌的癌变机制是及其发生展过程是一多种癌基因及肿瘤抑制基因参与，突变异常，互相调控的复杂过程，其癌基因有Ｒａｓ，ｅｒｂＢ，ｃ－ｍｙｃ，ＣｙｃｌｉｎＤ１等基因；肿瘤抑制基因ｐ５３，Ｒｂ，ＡＰＣ，ＭＣＣ，ＤＣＣ，ＭＴＳ等，本文重点介绍了３年来与食管癌有关的癌基因及肿瘤抑制基因的研究进展，有助于从分子水平上进一步研究食管癌的癌变机制。     

新的肿瘤抑制基因-ARLTS1

小分子GTP蛋白涉及肿瘤发生中多条信号通路的改变.类核糖基化因子肿瘤抑制基因1(ADP-ribosylation factor-like tumor suppressor gene 1 ,ARLTS1),是小分子GTP蛋白Ras超家族中ARF家族的成员之一.该基因是低显性基因,可因启动子超甲基化而失调.有两种ARLTS1的多态性与肿瘤的家族风险相关.ARLTS1表达下调与部分肿瘤发生有重要关系,而恢复其表达则会诱导caspase依赖的细胞凋亡发生,并减少肿瘤的体内生长.通过基因微阵列实验发现,转导ARLTS1基因诱导细胞凋亡过程中众多涉及细胞存活、增殖和发育的信号通路.     

KAI1肿瘤转移抑制基因研究新进展

KAI1是采用ALU-PCR法在人前列腺癌细胞的第11号染色体上分离出来的一种新的转移抑制基因.它可能参与肿瘤细胞-细胞、细胞-基质的粘附,其特殊的基因表达调控机制与人类多种肿瘤抑制基因关系复杂.研究表明,KAI1基因与乳腺癌、膀胱癌、肝癌、大肠癌等恶性肿瘤侵袭及转移抑制有关.     

MAGE-3基因编码的肿瘤排斥抗原在食管癌的表达

由于人类ＭＡＧＥ(ｍｅｌａｎｏｍａａｎｔｉｇｅｎ)基因编码的肿瘤排斥抗原(ｔｕｍｏｒｒｅｊｅｃｔｉｏｎａｎｔｉｇｅｎ)可为ＣＴＬ(ｃｙｔｏｔｏｘｉｃＴｌｙｍｐｈｏｃｙｔｅ)识别,且在许多肿瘤有较高的表达,而在正常组织(除了睾丸和胎盘外)均不表达,因而是一种ＣＴＬ介导的特异性免疫治疗的理想靶分子。在机体抗肿瘤免疫应答中,特异性ＣＴＬ的杀伤作用是主要的抗肿瘤机制,因而这一领域的研究,引起了国内外学者的极大重视。利用ＭＡＧＥ基因产物为靶分子的特异性免疫治疗在临床上已取得了一些令人鼓舞的成功〔1〕。目前,国内尚未见对Ｍ…     

肿瘤转移抑制基因Kai1的研究状况

随着分子生物学的深入研究 ,人们对肿瘤发生的分子基础有了明确的认识。然而 ,对威胁肿瘤患者生存的主要原因———肿瘤转移的分子基础却了解较少。目前已知 ,肿瘤转移与肿瘤发生一样 ,不仅有促进基因的激活 ,还伴有抑制基因的失活。肿瘤转移抑制基因的存在是在细胞融合实验中证实的。鼠前列腺癌细胞系ＡＴ3.1具有高转移特性 ,ＡＴ2 .1则是非转移的 ,两种细胞融合后 ,得到的细胞仍然保持肿瘤细胞的特点 ,却不具备高转移特性。将人的第 11号染色体转移到鼠高转移的前列腺癌细胞系ＡＴ6 .1中 ,也观察到相同的结果 ,提示有转移抑制基因定位于该…     

肿瘤抑制基因研究新进展——多肿瘤抑制基因MTS分子生物学简介

人类第9号染色体短臂不到40kb的座位发现了多肿瘤抑制基因(Multiple Tumor Sup-Pressor1和2,MTS1和MTS2)。它们分别编码两种蛋白:前者叫做P16蛋白,抑制依赖细胞周期素激酶 4(Cyclin-dependent Kinase 4,CdK4)。后者比P16小20多个残基,功能推测与P16相近。MTS1基因与p~(53)相比,它在75％的各种癌细胞中发生缺失;而p~(53)基因的缺失率在各种癌细胞中 为50％。P~(16)到目前为止发现的第一个直接控制细胞增殖周期的细胞固有蛋白,而P~(53)控制细胞增殖周期要通过P~(21)发挥抑制作用。     

RASSF1A基因甲基化与肿瘤的关系

RASSF1A(Ras association domain family 1 Agene) 是RAS相关结构域家族RASSF1基因的转录本A, 它编码一组RAS效应蛋白,它的启动子高甲基化及其基因外失活已在多种人肿瘤细胞株和原发性癌组织中普遍存在,它在多种恶性肿瘤的发生和诱导细胞凋亡的过程中发挥作用。     

TGF-β1基因启动子-800G/A、-509C/T多态性与食管癌的研究

目的研究转化生长因子β1(TGF-β1)基因启动子多态性各等位基因及基因型在食管癌患者中的分布频率,初步分析其基因型及血清水平与食管癌的相关性.方法采用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)技术,检测118例食管癌患者和130例正常对照组TGF-β1的基因多态性,包括TGF-β1基因启动子-800G/A、-509C/T位点,同时采用ELISA检测血清TGF-β1水平.结果食管癌患者血清TGF-β1水平显著高于对照组(P＜0.01),TGF-β1基因-800G/A位点多态性在食管癌组和正常人群中的分布差异无显著性(P＞0.05),而TGF-β1基因-509C/T多态性各等位基因及基因型频率在两组人群中的分布差异存在显著性(P＜0.05);等位基因频率的相对风险分析发现,T等位基因携带者患食管癌的风险是C等位基因的1.624倍(OR=1.624,95%CI1.134～2.324),携带T等位基因的食管癌患者血清TGF-β1水平显著高于不携带者(50.97±8.91μg/LVS44.23±8.54μg/L,P＜0.01).结论TGF-β1基因-509C/T多态性与食管癌的发病具有相关性,其中T等位基因可能是食管癌发病的遗传易感基因;携带T等位基因的个体可能通过促进TGF-β1的高度表达进而增加了食管癌的发病风险.     

FAP-1和RAC-1在原发性胰腺癌组织中的表达及其临床意义

目的探讨Fas相关磷酸酯酶1（FAP-1）和RAC-1在原发性胰腺癌中的表达及其与胰腺癌侵袭转移之间的关系。方法应用免疫组化SP技术,检测40例原发性胰腺癌组织中FAP-1和RAC-1的表达,分析其与胰腺癌侵袭转移之间关系。结果胰腺癌组织中FAP-1和RAC-1的表达明显高于胰腺正常组织（P〈0．01）,且两者存在相关性（P〈0．05）,同时FAP-1和RAC-1的表达有淋巴结转移表达明显高于无淋巴结转移组（P〈0．05）。FAP-1和RAC-1阳性表达与胰腺癌病理组织学分类无相关性（P〉0．05）。结论FAP-1和RAC-1的表达能反映原发性胰腺癌的侵袭转移能力,联合检测两种蛋白的表达对诊断胰腺癌具有一定临床意义。     

Alterations in the SMARCB1 (INI1) tumor suppressor gene in familial schwannomatosis

Schwannomatosis is a third major form of neurofibromatosis that has recently been linked to mutations in the SMARCB1 (hSnf5/INI1) tumor suppressor gene. We analyzed the coding region of SMARCB1 by direct sequencing and multiplex ligation-dependent probe amplification (MLPA) in genomic DNA from 19 schwannomatosis kindreds. Microsatellite markers in the SMARCB1 region were developed to determine loss of heterozygosity (LOH) in associated tumors. We detected four alterations in conserved splice acceptor or donor sequences of exons 3, 4 and 6. Two alterations that likely affect splicing were seen in introns 4 and 5. An additional four alterations of unclear pathogenicity were found to segregate on the affected allele in eight families including two non-conservative missense alterations in three families. No constitutional deletions or duplications were detected by MLPA. Nine of 13 tumors examined showed partial LOH of the SMARCB1 region consistent with 'second hits.' Alterations were detected in tumors both with and without somatic NF2 gene changes. These findings support the hypothesis that SMARCB1 is a tumor suppressor for schwannomas in the context of familial disease. Further work is needed to determine its role in other multiple and single tumor syndromes.     

Expression and clinical significances of Beclin1, LC3 and mTOR in colorectal cancer

Autophagy is related to cancer and other diseases, and compromised autophagy could promote chromosome instability associated with carcinogenesis and tumor progression. The role of autophagy in the growth and metastasis of colorectal cancer (CRC) remains poorly understood. Beclin1 mediates autophagic initiation, and LC3 is a specific marker for autophagy. Inactivation of mTOR caused by cellular hypoxia or energy deficiency induces autophagic activity. This study aims to examine the expression and clinical significance of these proteins in CRC. Immunohistochemistry results showed that the positive expression rates of Beclin1, LC3, and mTOR in cancer tissues were 90.50%, 87.19%, and 46.28%, respectively, which were higher than those in adjacent tissues (P < 0.05). Differentiation degree and lymph node metastasis were associated with LC3 overexpression (P < 0.05) but not with Beclin1 (P > 0.05). Lymph node metastasis was also related to mTOR. Spearman analysis results showed that LC3 expression was positively correlated with Beclin1 but negatively correlated with mTOR (r = 0.593 and -0.165, respectively; P < 0.01). Beclin1 expression was also not associated with mTOR (P > 0.05). Survival analysis further indicated that LC3, mTOR, and lymph node metastasis were independent prognostic factors in CRC. Real-time PCR results and Western blot indicated that Beclin1, LC3, and mTOR expression in CRC was significantly higher than that in adjacent tissues (P < 0.01). The aberrant protein expression may be associated with the development and progression of CRC. The LC3 and mTOR genes must be simultaneously detected to evaluate progression and prognosis of CRC.     

Immunohistochemical assessment of PRL-3 (PTP4A3) expression in tumor buds, invasion front, central region of tumor and metastases of colorectal cancer

PurposeThe aim of the study was to evaluate immunohistochemical expression of PRL-3 protein tumor buds, invasion front, central region of tumor and metastases of colorectal cancer.Material/MethodsThe PRL-3 expression was analyzed in 103 colorectal carcinoma patients, using the immunohistochemical method with a monoclonal antibody 3B6 anti-PRL-3 (Attogen Biomedical Research, USA)ResultsPositive reaction for PRL-3 was observed in 36.9% of cases in the central region of tumor, in 64.3% in the invasion front, and in as many as 81.4% in buds (present in 70/103 cases), in 100% in metastases to local lymph nodes, in 100% in metastases to the liver and in 97.1% in metastases to the lungs. The findings indicate that cancer cells obtain this protein already in the early stages of metastasizing. PRL-3 is present not only in metastases to local lymph nodes but also to distant organs. It is likely that PRL-3 protein takes part in the initiation of metastasizing of cancer cells. Also the presence of lymph and blood vessel invasion was found only to correlate with increased percentage of patients with strong PRL-3 expression in tumor buds (p=0.046).ConclusionOur results may suggests the participation of PRL-3 protein as a marker of the presence of colorectal cancer metastasis to the lymph nodes and distant metastases, which is independent of parameters such as gender and age of the patients, tumor location, histological type and grade of histological malignancy and stage of tumor.     

精氨酸酶1在食管癌患者外周血的表达及其临床意义

目的检测精氨酸酶1(arginase1,Arg1)在食管癌中的表达,分析其与髓源性抑制细胞(myeloid-derived suppressorcells,MDSCs)消长的关系,探讨癌症患者机体免疫抑制状态的可能机制。方法应用流式细胞术检测30例食管癌患者PBMC中的MDSCs比例;实时荧光定量PCR检测PBMC中Arg1、IL-6和TNF-αmRNA的表达水平;酶联免疫吸附试验(ELISA)检测血浆Arg1,IL-6和TNF-α含量。结果食管癌患者外周血PBMC中MDSCs比例及Arg1的mRNA水平均明显高于健康对照组(P<0.05),而IL-6和TNF-α的mRNA水平均低于健康对照组(P<0.05)。食管癌患者血浆Arg1含量高于健康对照组(P<0.05),而IL-6和TNF-a含量与健康对照组相比无明显差异(P>0.05)。此外,食管癌患者Arg1 mRNA水平和蛋白水平均与MDSC含量呈正相关(P<0.01)。结论 Arg1在食管癌患者外周血中的高表达与MDSCs水平和食管癌的发生、发展有着密切的关系,其检测将有助于临床食管癌的辅助诊断和预后判断。     

MDC1和MMR蛋白在子宫内膜癌中的表达及临床意义

目的探讨DNA损伤检查点蛋白调节子1(MDC1)与错配修复(MMR)蛋白在子宫内膜癌中的表达及其与相关临床特征的关系。方法回顾性分析126例子宫内膜癌患者的临床及病理资料,收集患者手术或刮宫标本进行HE染色和免疫组化染色,检测MDC1、MMR蛋白(MSH6、MSH2、PMS2、MLH1)的表达,并根据MDC1及MMR蛋白免疫组化结果,分析MDC1、MMR蛋白表达及结合两种蛋白不同表达与患者临床特征的关系。采用Kaplan-Meier法绘制生存曲线图分析MDC1和MMR蛋白联合检测与总生存率的关系。采用Spearman秩相关性分析MDC1与MMR蛋白表达的相关性。结果与MDC1阳性表达患者相比,MDC1阴性表达患者年龄较小,主要为低级别(1~2级)子宫内膜样腺癌(P<0.05);与MMR表达完整(MMR-p)患者相比,MMR表达缺失(MMR-d)患者年龄较小,主要为低级别(1~2级)子宫内膜样腺癌(P<0.05)。MDC1阴性表达/MMR-p、MDC1阳性表达/MMR-p、MDC1阴性表达/MMR-d、MDC1阳性表达/MMR-d各组患者年龄、组织学类型、组织学分级比较,差异具有统计学意义(P<0.05);而临床分期、肌层浸润深度比较,差异无统计学意义(P>0.05)。MDC1、MMR蛋白联合检测与患者的总生存率无关(P>0.05),MDC1阴性表达占所有子宫内膜癌患者的9.5%(12/126),与MMR-d呈正相关(P<0.001)。结论MDC1、MMR蛋白多在低级别子宫内膜癌中失表达,并且MDC1阴性表达与MMR-d具有正相关性,提示MDC1失表达与子宫内膜癌的微卫星不稳定性密切相关。     

胃癌组织中TSLC1的表达及临床意义

目的：探讨肺癌肿瘤抑制物1(tumor suppressor in lung cancer 1, TSLC1)蛋白表达与胃癌发生、发展的关系。方法采用免疫组化法检测TSLC1蛋白在20例正常胃黏膜、30例胃上皮内瘤变和50例胃癌组织中的表达,并复习相关文献。结果TSLC1在胃癌中的阳性率为14．00%,低于胃上皮内瘤变(46．67%)及正常胃黏膜(95．00%)( P<0．05)。 TSLC1在高级别上皮内瘤变中的表达低于低级别上皮内瘤变及正常胃黏膜( P<0．05)。 TSLC1在高级别上皮内瘤变及胃癌组织中的表达差异无显著性(P>0．05)。胃癌中 TSLC1表达与淋巴结转移和TNM分期密切相关(P<0．05)。结论 TSLC1表达与胃癌的发生、发展有关,可能为胃癌的防治提供新方向。