Analysis of N-ras gene mutation and p53 gene expression in human hepatocellular carcinomas

AIM:To study the relationship between N-ras gene mutation and p53 gene expression in the carcinogenesis and the development of human hepatocellular carcinomas (HCC).METHODS:The N-ras gene mutation and the p53 gene expression were analyzed in 29 cases of HCC by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and immunohistochemistry.RESULTS:Thirteen cases of HCCs were p53 positive (44.8%), which showed a rather high Cpercen-tage of p53 gene mutation in Guangxi. The aberrations at N-ras codon 2-37 were found in 79.31% of HCCs and 80.77% of adjacent non-tumorous liver tissues. More than 2 point mutations of N-ras gene were observed in 22 cases (75.86%). Twelve cases (41.37%) of HCCs showed both N-ras gene mutation and p53 gene expression.CONCLUSION:N-ras gene and p53 gene may be involved in the carcinogenesis and the development of HCC.That 38% of HCCs with N-ras gene mutation did not express p53 protein indicates that some other genes or factors may participate in the carcinogenesis and the development of HCC.     

人Midkine基因启动子片段的克隆

目的克隆人Midkine（MK）启动子基因2 335bp片段.方法自健康人血中提取人类基因组DNA作为模板,聚合酶链式反应（PCR）技术克隆人MK启动子基因2 335bp片段.琼脂糖凝胶电泳初步鉴定PCR产物,切取目的条带纯化并将其克隆入p GEM T载体中.选取阳性克隆进行DNA测序.结果电泳结果显示PCR产物包含有大小约为2 300 bp和1 400 bp的条带各1条;较大片段的测序结果显示,其与Genbank中的人MK启动子片段吻合.结论本研究成功克隆了人MK启动子基因2 335 bp片段.     

人肝癌父系表达基因10的遗传印记状态

目的 研究人肝癌组织及肝癌细胞株中父系表达基因10(PEG10)的遗传印记状态.方法 从40例肝癌及其癌旁组织、15例正常肝组织、5株肝癌细胞(PLC/PRF/5、SMMC 7721、HepG2、Hep3B、SK-HEP-1)、2株正常肝细胞(changliver、HL7702)中提取基因组DNA,针对PEG10基因单核苷酸多态性位点设计引物进行PCR,扩增片段经测序分析基因型;从杂合样本中提取总RNA进行RT-PCR,对扩增产物测序以检测等位基因表达状态,同时进行实时荧光定量RT-PCR检测PEG10表达水平.计量资料以均数±标准差(-x±s)表示,组间比较用t检验与方差分析;两组率的比较用x2检验.结果 40例肝癌及其癌旁组织中16例呈杂合状态,15例正常肝组织中3例呈杂合状态,肝癌细胞HepG2扩增片段测序检测到一杂合突变位点,其余组织及细胞株均为纯合状态.杂合样本中,82.4%(14/17)肝癌样本(包括组织及肝癌细胞株)中PEG10基因呈双等位基因表达,发生印记丢失;17.6%(3/17)肝癌样本呈单等位基因表达,提示印记存在.PEG10在癌旁及正常肝组织中几乎不表达.发生印记丢失的肝癌组织与印记存在的肝癌组织相比,PEG10表达水平的差异无统计学意义(t=1.311,P＞0.05).结论 大多数肝癌组织中存在PEG10印记丢失现象,PEG 10印记状态与其在肝癌组织中的表达水平无明确关系.     

Expression of androgen receptor mRNA in human hepatocellular carcinomas and hepatoma cell lines.

The expression of androgen receptor messenger RNA in hepatocellular carcinomas and hepatoma cell lines was studied using Northern-blot analysis and the complementary DNA-polymerase chain reaction method. Androgen receptor messenger RNAs were detected (although in low levels) in both hepatocellular carcinoma tissues and noncancerous tissues of the liver in all eight cases we studied, except for the tumor sample of one case. None of the hepatoma cell lines studied, however, expressed detectable levels of androgen receptor messenger RNA except for the SK-HEP-1 hepatoma cell line.     

Regulatory peptide receptors in human hepatocellular carcinomas

BACKGROUND: Overexpression of regulatory peptide receptors in selected human tumours is of diagnostic and therapeutic relevance. AIMS: To evaluate the expression of somatostatin, vasoactive intestinal peptide (VIP), substance P, cholecystokinin (CCK) A and B, and neurotensin receptors in hepatocellular carcinoma (HCC). METHODS: In vitro receptor autoradiography for the various peptide receptors using selective iodinated radioligands on tissue sections in 59 cases of HCC. RESULTS: 41% of HCC expressed somatostatin receptors; 47% expressed VIP receptors. VIP receptors were always identified in non-neoplastic liver tissue. Substance P receptors were only identified in 5% of HCC but in the majority of their peritumorous and intratumorous vessels. CCK-A and -B and neurotensin receptors were not detected in HCC. The somatostatin receptors showed high affinity for somatostatin and octreotide. The VIP receptors had high affinity for VIP, pituitary adenylate cyclase activating peptide (PACAP) 27, and a VIP1 selective analogue, suggesting the presence of VIP1/PACAP II type receptors. PACAP I receptors were identified in two cases. Substance P receptors were all of the NK1 subtype. The density of somatostatin receptors in HCC was low compared with the density found in liver metastases of neuroendocrine tumours. The VIP receptor density was always lower in HCC than in adjacent liver tissue. CONCLUSIONS: Somatostatin, VIP, and substance P may have a receptor mediated role in HCC. Substance P receptors may be involved in regulation of tumour associated blood flow; somatostatin receptors and VIP receptors may mediate tumour growth. Diagnostic and therapeutic evaluation of somatostatin and VIP analogues may be of interest in receptor positive HCC.     

Expression of metastasis suppressor gene nm23 in human hepatocellular carcinoma

AIM: To investigate the relationship between the expression of nm23-Hi mRNA and the metastatic potential of hepatocellular carcinoma (HCC). METHODS: The expression of nm23-H1 mRNA was detected in 24 cases of HCC by in situ hybridization using digoxigenin-labeled nm23-H1 antisense cRNA probe. Twenty-four HCC specimens were divided into two groups according to the following criteria: (1) metastasis in portal lymph nodes; (2) the number of tumors in the liver; (3) cancerous emboli in the portal vein; and (4) the existence of satellite lesions. We named those meeting criteria (1) or (2) and (3), or (3) and (4) high metastatic potential (n = 6); and the others formed the low metastatic potential group (n = 18). RESULTS: Positive results of in situ hybridization showed granules or masses in the cytoplasm. In the low metastatic potential group strong staining was obtained in ten specimens, while in the high metastatic potential group there was none. Three negative results were found in the high metastatic potential group, and one in the low metastatic potential group (P < 0.05). The expression of nm23-H1 mRNA was not correlated with some clinical factors, such as tumor size or the background liver disease. CONCLUSION: The expression of nm23-H1 mRNA is inversely correlated with HCC metastatic potential, and can be considered as an index which indicates the metastatic potential of HCC.     

SOCS1基因与肝细胞癌的关系研究进展

SOCS1基因位于16p12-p13.1,它编码蛋白SOCS1并属于SOCS蛋白家族,通过抑制JAK—STAT信号转导通路发挥作用,其失活机制主要是甲基化和杂合性缺失。SOCS1在肝细胞癌中广泛甲基化和表达明显降低,提示SOCS1可能是抑癌基因,在肝细胞癌的发生发展中起十分重要的作用。     

肝癌细胞BEL7402中神经元特异性烯醇化酶的表达

目的:分别从转录水平、蛋白水平及细胞水平检测人神经元特异性烯醇化酶(NSE)在肝癌细胞BEL7402中的表达情况.方法:利用NSE特异引物,通过逆转录聚合酶链式反应(RT-PCR)从人肝癌细胞BEL7402中扩增人NSE基因的转录产物,采用免疫印迹(Westernblot)、免疫细胞化学(ICC)染色技术检测NSE在肝癌细胞中的表达.结果:通过RT-PCR方法可以从BEL7402中扩增1305bp的NSE产物;Westernblot方法证实BEL7402细胞可以表达Mr50000的NSE蛋白;免疫细胞化学染色显示BEL7402与抗NSE单抗呈阳性反应,这说明从转录水平、蛋白水平及细胞水平均检测到了NSE在肝癌细胞BEL7402中的表达.结论:NSE可在肝癌细胞BEL7402转录和表达.     

STAT3基因在原发性肝癌组织中的表达及意义

目的探讨STAT3基因在肝癌发生发展中的作用及意义。方法应用RT-PCR检测STAT3基因及相关基因c-myc、p53、survivin、VEGF的mRNA水平的表达,应用Western Blot法及免疫组化法检测STAT3基因的蛋白水平及定位表达。结果肝癌组织及癌旁组织中STAT3基因mRNA的表达均明显高于正常肝组织(P<0.05),肝癌及癌旁组织中c-myc、survivin、VEGF基因mRNA的表达上调,p53基因mRNA的表达下调,肝癌组织及癌旁组织中STAT3基因蛋白水平的表达均高于正常肝组织(P<0.05)。结论STAT3基因的持续激活在肝癌的发生发展中起重要作用,可作为早期诊断的指标及治疗的新靶点。     

MAGE-4基因在肝细胞肝癌中的表达及临床意义

目的通过研究MAGE-4基因在肝细胞肝癌组织中的表达,并与患者临床资料进行分析,探讨 MAGE-4基因与肝细胞肝癌(HCC)患者临床指标及转移与复发的关系,为MAGE-4基因编码蛋白用于HCC患者免疫治疗提供依据. 方法用RT-PCR的方法对31例HCC患者癌组织及相应癌旁组织MAGE-4基因表达进行测定,对全部RT-PCR扩增产物中目的基因片段进行DNA测序以证实其为 MAGE-4基因,患者均测定并统计AFP、AFU、抗HCV、HBsAg、AFP mRNA、肿瘤直径等临床指标. 结果 31例HCC患者肝癌组织中MAGE-4基因表达的阳性率38.7% (12/31)明显高于癌旁组织中MAGE-4基因表达的阳性率0% (0/31),P＜0.01.HCC患者肝癌组织中MAGE-4基因表达的阳性率与患者AFP、AFU、抗HCV、HBV标志物、AFP mRNA、肿瘤直径等临床指标均无关,P＞0.05. 结论 MAGE-4基因在HCC患者肝癌组织中特异高表达,可能作为HCC患者免疫治疗攻击的靶点,HCC患者肝癌组织中 MAGE-4基因表达的阳性率与HCC患者肿瘤标志物、转移、复发均无关.     

人肝细胞癌中转移抑制基因nm23编码蛋白的表达

目的探讨肝脏冷保存与移植肝原发性无功能的关系。方法采用具有免疫耐受性的同种大鼠原位肝移植模型进行研究。将鼠肝分别在４℃ＵＷ液中保存１，６和２４ｈ，分别在移植后１ｈ和２４ｈ取肝脏做病理观察。结果保存在ＵＷ液中的肝脏基本保存了正常的组织结构，而在移植后则不同程度地出现了变性或坏死，并且肝细胞的坏死是以小叶中央静脉为中心。保存时间越长，病变越严重。结论肝脏冷保存时间与移植肝原发性无功能的发生密切相关。     

Decreased expressions of hepsin in human hepatocellular carcinomas.

BACKGROUND/AIMS: Hepsin is a type II transmembrane protein predominantly expressed in the liver and has been implicated in participation in blood coagulation pathway and epithelial carcinogenesis. The aim of this current study is to investigate the role of hepsin in hepatocarcinogenesis. METHODS: Quantitative real-time RT-PCR was used to investigate the expression levels of hepsin in a total of 50 paired hepatocellular carcinomas (HCCs) and the corresponding non-tumor liver tissues. Hepsin was transfected to the hepsin-non-expressing SK-HEP-1 cells to study the change of cell proliferation. RESULTS: In 62% (31/50) patients, the expression levels of hepsin in non-tumor liver tissues are at least twofold higher than those in the corresponding HCC tissues. Positive hepatitis B surface antigen was more often detected in patients with hepsin underexpressed in the HCC tissues (74.2% vs. 31.6%, P=0.007). Patients with hepsin underexpressed in the HCC tissues survived shorter time than those without hepsin underexpression in the HCC tissues. The cell proliferation and for a colony formation of SK-HEP-1 HCC cells were inhibited by hepsin. CONCLUSIONS: Most HCC patients had hepsin underexpressed in the HCC tissues. These patients survived for a shorter time compared with those without hepsin underexpression in the HCC tissues. Hepsin expression could inhibit cell proliferation and colony formation of HCC cells.     

组织型转谷氨酰胺酶在肝癌组织中高表达

组织型转谷氨酰胺酶（TGaSe-2）是转谷氨酰胺酶（TGase：EC2．3．2．13）家族发现最早的一个成员，它催化酰基转移反应，使翻译后的多肽链形成交联蛋白，同时具有GTP水解酶的作用。研究表明，TGase-2影响到肿瘤细胞生长、分化、凋亡以及肿瘤转移等生理、病理过程。TGase-2表达的异常或活性的失调，可能与人类乳腺癌㈤、[第一段]     

肝癌组织中内质网蛋白基因表达及其功能的初步研究

为研究肝癌中内质网蛋白基因(RTN)表达及初步功能。利用免疫组化、真核转染、体内外抑瘤试验等方法。结果显示肝癌中RTN呈下调表达，RTN蛋白主要定位于细胞浆和细胞膜，并且与肝癌的淋巴结转移有关。转染RTN后，体外肝癌细胞生长率明显减少，一些基因表达发生改变，体内肿瘤抑制率为85．64％。转染RTN细胞产生肿瘤的坏死级别较高于其它两组。RTN可能作为候选抑癌基因在肝癌发生中起重要作用。