Expression of P450 and nuclear receptors in normal and end-stage Chinese livers

AIM: To investigate the expression of P450 enzyme genes by using end-stage liver disease samples and trimmed normal Chinese donor livers.METHODS: The end-stage liver disease samples [n = 93, including hepatocellular carcinoma (HCC), peri-HCC tissue, hepatitis B virus cirrhosis, alcoholic cirrhosis, and severe cirrhosis] and trimmed normal Chinese donor livers (n = 35) from The Institute of Organ Transplantation in Beijing, China. Total RNA was extracted, purified, and subjected to real-time RT-PCR analysis.RESULTS: For cytochrome P450 enzymes 1 (CYP1) family, the expression of CYP1A2 was decreased 90% in HCC, 80% in alcoholic cirrhosis, and 65% in severe cirrhosis. For CYP2 family, the expression of CAR was decreased 50% in HCC, but increased 50% in peri-HCC tissues. Similar decreases (about 50%) of CYP2B6, CYP2C9, CYP2C19, CYP2D6 and CYP2E1 were observed in HCC, as compared to peri-HCC tissues and normal livers. CYP2C19 were decreased in all end-stage liver diseases and CYP2E1 also decreased in alcoholic cirrhosis and severe cirrhosis. For CYP3 family, the expression of PXR was decreased 60% in HCC, together with decreases in CYP3A4, CYP3A5, and CYP3A7. In contrast, the expression of CYP3A7 was slightly increased in HBV cirrhosis. The expression of CYP4A11 was decreased 85% in HCC, 7% in alcoholic cirrhosis and severe liver cirrhosis, along with decreases in PPARα. The 93 end-stage livers had much higher inter-individual variations in gene expression than 35 normal livers.CONCLUSION: The expression of CYP enzyme genes and corresponding nuclear receptors was generally decreased in end-stage liver diseases, and significant differences in gene expression were evident between peri-HCC and HCC.     

Expression of TNF-related apoptosis-inducing Ligand receptors and antitumor tumor effects of TNF-related apoptosis-inducing Ligand in human hepatocellular carcinoma

AIM: To investigate the expression of TNF-related apoptosis -inducing Ligand (TRAIL) receptors and antitumor effects of TRAIL in hepatocellular carcinoma (HCC). METHODS: Expression of TRAIL receptors was determined in 60 HCC tissues, 20 normal liver samples and two HCC cell lines (HepG2 and SMMC-7721). The effects of TRAIL on promoting apoptosis in HCC cell lines were analyzed after the cells were exposed to the recombinant TRAIL protein, as well as transfected with TRAIL-expression construct. In vivo effects of TRAIL on tumor growth were investigated by using nude mice HCC model of hepG2. RESULTS: Both death receptors were expressed in all HCC tissues and normal hepatic samples. In contrast, 54 HCC tissues did not express DcR1 and 25 did not express DcR2. But both DcR were detectable in all of the normal liver tissues. The expression patterns of DR and DcR in HCC samples (higher DR expression level and lower DcR expression level) were quite different from those in normal tissue. DR5, DR4, and DcR2 expressed in both cell lines, while no DcR1 expression was detected. Recombinant TRAIL alone was found to have a slight activity as it killed a maximum of 15 % of HCC cells within 24 h. Transfection of the TRAIL cDNA failed to induce extensive apoptosis in HCC lines. In vivo administration of TRAIL gene could not inhibit tumor growth in nude mice HCC model. However, chemotherapeutic agents or anticancer cytokines dramatically augmented TRAIL-induced apoptosis in HCC cell lines. CONCLUSION: Loss of DcR (especially DcR1) in HCC may contribute to antitumor effects of TRAIL to HCC.HCC is insensitive towards TRAIL-mediated apoptosis, suggesting that the presence of mediators can inhibit the TRAIL cell-death-inducing pathway in HCC. TRAIL and chemotherapeutic agents or anticancer cytokines combination may be a novel strategy for the treatment of HCC.     

Expression of liver cancer associated gene HCCA3

AIM:To study and clone a novel liver cancer related gene,and to explore the molecular basis of liver cancer genesis.METHODS:Using mRNA differential display polymerssechain reaction(DDPCR),we investigated the difference ofmRNA in human hepstocallular carcinoma(HCC)and pairedsurrounding liver tissues,and got a gene probe.Byscreening a human placenta cDNA library and genornichomologous extend,we obtained a full-length cDNA namedHCCA3.We analyzed the expression of this novel gene in 42pairs of HCC and the surrounding liver tissues,anddistribution in human normal tissues by mssns of Northernblot assay.RESULTS:A full-length cDNA of liver cancer associated geneHCCA3 has been submitted to the GeneBank nucleotidesequence databases(Accession No.AF276707).Thepositive expression rate of this gene was 78.6%(33/42)inHCC tissues,and the clinical pathological data showed thatthe HCCA3 was closely associated with the invasion oftumor capsule(P=0.023)and adjacant small metastasissatellite nodules lesions(P=0.041).The HCCA3 was widelydistributed in the human normal tissues,which wasIntensively expressed In lungs,brain and colon tissues,while lowly expressed In the liver tissues.CONCLUSION:A novel full-length cDNA was cloned anddifferentiated,which was highly expressed in liver cancertissues.The high expression was closely related to thetumor invssivensss and metastasis,that may be the lateheredited change in HCC genssis.     

Expression of PTEN, PPM1A and P-Smad2 in hepatocellular carcinomas and adjacent liver tissues

AIM: To investigate the expressions of PTEN, PPM1A and P-Smad2 in hepatocellular carcinoma (HCC) and their significance. METHODS: The expressions of PTEN, PPM1A and P-Smad2 in 31 HCC tissues, 25 adjacent liver tissues and 13 non-tumor liver tissues were detected by using Envision immunohistochemical technique. RESULTS: The positive expression (64.52%) and staining intensity (4.19 ± 3.31) of PTEN in the cytoplasm of HCC were significantly lower and weaker than those in the adjacent or non-tumor liver tissues (97.37%, 7.88 ± 0.93; 100%, 7.77 ± 0.93, respectively) (P < 0.05), and its staining intensity in the cytoplasm of HCC, which belongs to Edmondson pathologic grades Ⅱ-Ⅲ and above, was also lower than that of gradeⅠandⅠ-Ⅱ. Furthermore, its location in the nucleus or cytoplasm of liver cells was negatively correlated with the progression of liver disease (r = -0.339, P = 0.002); most of PPM1A might be only expressed in the nucleus of adjacent liver tissues, non-HCC tissues or Edmondson gradeⅠandⅠ-Ⅱ HCC, but it was mainly expressed in the cytoplasm of HCC with Edmondson grade ≥Ⅱ, weakly or negatively expressed in the nucleus (P < 0.05), and its location was negatively correlated with the progression of liver disease (r = -0.45, P = 0.0000). P-Smad2, which was mostly located in the nucleus and cytoplasm of gradeⅠ andⅠ-Ⅱ HCC, surrounding or non-tumor liver tissues, was only in the nucleus of HCC with Edmondson grade Ⅱ and above (P < 0.001), and its location was positively correlated with the disease progression (r = 0.224, P = 0.016). Spearman correlation analysis revealed that P-Smad2 was significantly negatively correlated with PTEN and PPM1A (r = -0.748, P = 0.000; r = -0.366, P = 0.001, respectively); and PTEN and PPM1A were positively correlated with HCC carcinogenesis (r = 0.428, P = 0.000). CONCLUSION: The aberrant location of expression and staining intensity of PTEN, PPM1A and P-Smad2 in HCC and their relationship might have an impact on the pathogenesis of HCC.     

Cloning and expression of MXR7 gene in human HCC tissue

AIM To clone and identify the whole cDNA of MXR7 gene and to find out its expression in human HCC, and normal tissues.METHODS The DNA primers were designed and synthesized according to the whole cDNA sequence of MXR7 gene. The cDNA of human HCC was taken as the template while the cDNA of MXR7 gene was synthesized by polymerase chain reaction (PCR). Recombinant DNA conforming to reading frame was constructed by connecting purified PCR product of the cDNA of MXR7 gene with expression vector pGEX-5X-1 of fusion protein. The plasmid MXR7/pGEX-5X-1 was identified by sequencing. Using 32P labeled MXR7 cDNA as probe, MXR7 mRNA expression was detected by Northern blot analysis in 12 different human normal tissues, 7 preoperatively untreated non-liver tumor tissues, 30 preoperatively untreated HCC, the paracancerous liver tissues and 12 normal liver tissues samples.RESULTS Restriction enzyme and sequence analysis confirmed that the insertion sequence in vector pGEX-5X-1 was the same as the cDNA sequence of MXR7 gene. Northern blot analysis showed no expression of MXR7 mRNA in 12 kinds of normal human tissues including liver, 7 tumor tissues in other sites and 12 normal liver tissues, the frequencies of MXR7 mRNA expression in HCC and paracancerous liver tissues were 76.6% and 13.3%, respectively.The frequency of MXR7 mRNA expression in HCC without elevation of serum AFP and in HCC ＜5cm was 90% (9/10) and 83.3% (5/6),respectively.CONCLUSION MXR7 mRNA is highly expressed in human HCC, which is specific and occurs at an early stage of HCC, suggesting MXR7 mRNA can be a tumor biomarker for HCC. The detection of MXR7 mRNA expression in the biopsied liver tissue is helpful in discovering early subclinical liver cancer in those with negative serum AFP.     

Expression of microsomal prostaglandin E synthase-1 in human hepatocelluar carcinoma.

BACKGROUND/AIMS: The objective of this study was to evaluate the expression of microsomal prostaglandin E synthase-1 (mPGES-1) in hepatocellular carcinoma (HCC) tissues. METHODS: Forty surgically resected HCC tissues with adjacent non-tumorous liver tissues and 14 surgically resected, histologically normal liver tissues were used. The immunohistochemical expressions of the mPGES-1 protein in these HCC tissues and normal control livers were analysed. mPGES-1 mRNA expression was also analysed by the real-time polymerase chain reaction method using the same tissues. RESULTS: Microsomal prostaglandin E synthase-1 was not expressed in hepatocytes but instead in vascular endothelial cells and bile duct epithelial cells in normal liver tissues. The mPGES-1 expression in HCC tissues was significantly greater than its expression in the non-tumorous tissues. All types of HCC expressed more mPGES-1 than normal or hepatitis livers, and the levels of mPGES-1 expression in poorly differentiated HCC were similar to the levels in well-differentiated HCC. The mPGES-1 mRNA expression paralleled its protein expression in these tumorous and non-tumorous tissues. CONCLUSIONS: The present study is the first to demonstrate a high expression of mPGES-1 in well-differentiated HCC as well as in poorly differentiated HCC. These findings suggest that mPGES-1 may play a role in the advanced as well as early stage of hepatocarcinogenesis.     

基因芯片在肝细胞癌相关基因筛选中的初步研究

目的探讨基因表达谱芯片技术在筛查肝细胞癌相关基因群表达中的作用。方法采用美国Affymetrix公司的U133A2．0基因表达谱芯片，按一步法抽提肝细胞癌及正常肝脏组织总RNA，分离纯化两种组织的mRNA；经逆转录合成掺人生物素标记的cDNA合成探针，与芯片杂交和严格洗片后，用荧光扫描仪扫描芯片荧光信号图像，分析肝细胞癌及正常肝组织中差异表达的基因。结果在18400条基因中，肝细胞癌组织与正常肝脏组织间有2756条（14．98％）存在差异表达的基因，其中上调基因1772条和下调基因984条，对2756条差异表达基因作了初步功能分类，这些基因与肝细胞癌的发病机制存在相关性。结论基因表达谱芯片技术可以筛选出肝细胞癌表达异常的相关基因群，对其进一步研究有助于认识肝细胞癌的发病机制。     

Gradual upregulation of OCI-5 expression during occurrence and progression of rat hepatocellular carcinoma

BACKGROUND: OCI-5, the rat homologene of human glypican 3 ( GPC3), is confirmed upregulated in hepatocellular carcinoma (HCC). The present study was undertaken to detect gene expression change of OCI-5 during occurrence and progression of rat HCC. METHODS: Male Sprague-Dawley rats were given diethyl-nitrosamine ( DENA) to induce HCC. Three DENA-induced rats and one control rat were sacrificed every week for 18 weeks during the development of HCC. Tissues specimens were snap-frozen in liquid nitrogen and total RNA was isolated. Sk-Hepl cells were treated with DENA at different concentrations. The gene expression levels of OCI-5 and GPC3 were detected with the RT-PCR method. RESULTS: OCI-5 was not expressed in normal rat liver tissues. When HCC occurred and aggravated, OCI-5 expression was gradually elevated to a very high level. GPC3 was not expressed in the DENA-treated Sk-Hepl cells. CONCLUSIONS: OCI-5 was not expressed in normal rat liver tissues but in rat HCC tissues. High-expression of OCI-5 in DENA-induced rat HCC model was the gene expression change of HCC not the DENA-induced gene expression. The expression level of OCI-5 was not only elevated in rat HCC but also gradually along the occurrence and progression of HCC, indicating that GPC3 might serve as a sensitive marker of early stage HCC.     

肝细胞癌Autotaxin cDNA部分序列测定及其意义

进行肝癌Ａｕｔｏｔａｘｉｎ（ＡＴＸ）ｃＤＮＡ部分序测测定,观察ＡＴＸ ｍＰＲＮＡ在肝癌组织中的表达程序,以探讨ＡＴＸ在肝癌转移机理中的作用。方法 提取肝癌７７２１细胞株,５例正常肝组织,３２肝癌组织ＲＮＡ,参照黑色素瘤ＡＴＸ ｍＲＮＡ表达程序分析,同时７７２１细胞株ＲＴ－ＰＣＲ产物进行ｃＤＮＡ序列测定显示与黑色素具有９９。７％的同样性;癌组织ＡＴＸ ｍＲＮＡ表达显著高于正常肝组织。结论 肝癌及正常     

Expression and significance of new inhibitor of apoptosis protein survivin in hepatocellular carcinoma

AM: To investigate expression and significance of inhibitor of apoptosis protein survivin in hepatocellular carcinoma (HCC). METHODS: The expression of survivin and vascular endothelial growth factor (VEGF) was investigated in 38 cases of HCC tissues and 38 liver cirrhosis tissues by immunohistochemistry and Western blot. The relationship between the expression of survivin and clinicopathological factors of HCC was analyzed. RESULTS: Survivin protein was detected in 23 (60.5%) of 38 HCCs and 3 (7.9%) of 38 liver cirrhosis tissues. In 23 cases of HCC which expressed survivin, the expression of VEGF was positive in 18 cases and slight positive or negative in 5 cases. While in 15 cases of HCC which did not express survivin, 12 cases did not express or slightly expressed, and 3 cases expressed VEGF. In liver cirrhosis tissues, the expression of VEGF was as follows: 24 cases were negative, 10 cases were weak positive and 4 cases were strong positive. The expression of survivin was coincident with the expression of VEGF in HCC (P<0.01). The expression of survivin in HCC had no relationship with the patients' age, gender, tumor size and differentiation level of HCC, while it was related to the metastasis of HCC. The protein quantitative analysis by Western blot also showed that overexpression of survivin in HCC was closely correlated to the expression of VEGF (P<0.01). Furthermore, stronger expression of survivin and VEGF was also found in patients with metastasis rather than in those with no metastasis (P<0.01). CONCLUSION: Survivin plays a pivotal role in the metastasis of HCC, and it has some correlation with tumorigenesis. The expression of survivin in the primary lesion is very useful as an indicator for metastasis and prognosis of HCC. It could become a new target of gene therapy of HCC.     

正常肝组织与肝癌组织差异表达基因消减cDNA文库的构建

目的 构建人正常肝组织与肝癌组织差异表达基因的消减cDNA文库。方法 采用新近建立的抑制消减杂交技术,以癌旁正常肝组织及肝癌组织作为对比材料,分离肝癌组织中不表达或低表达基因的cDNA片段,将其与T载体进行T/A连接构建文库,将连接产物用电穿孔法转化大肠杆菌进行文库扩增后,随机挑取100个白色克隆进行酶切鉴定。结果 扩增消减cDNA文库获得4000余个白色阳性克隆,随机挑取的100个白色克隆进行酶切鉴定。结果 扩增消减cDNA文库获得4000余个白色阳性克隆,随机挑取的100个白色克隆经酶切后均有200-600bp的插入片段。结论 用SSH法及T/A克隆技术成功构建了正常肝组织与肝癌组织差异表达基因的消减cDNA文库,该文库的建立为进一步筛选、克隆肝癌组织中失活或低表达的新的抑癌基因奠定了基因。     

用cDNA阵列技术研究黄曲霉毒素B1诱发树鼩肝癌形成过程中的基因变化

目的 对树鼩肝癌形成过程中的基因表达差异进行动态分析,探讨肝癌发生的分子机制。 方法用cDNA阵列技术,将2例黄曲霉毒素B1诱发的树鼩肝癌组织分别与其癌旁组织和其肝癌形成前的活检肝组织、实验前对照和同期对照肝组织进行基因表达水平的6种比较分析。结果 不同的比较方式所显示的差异表达的基因谱不同,可归为4类:癌组织表达高于癌旁组织、癌旁组织表达高于癌发生前肝的组织;癌与癌旁表达水平相仿,但高于癌发生前的肝组织;癌组织下调,低于癌旁组织;癌发生前表达上调,在癌发生后表达下调。 结论 对肝癌形成过程中不同时期的肝组织基因表达水平进行动态对比分析,有助于阐明肝癌发生的分子机制并最终筛选出与肝癌发生有关的关键基因。     

应用基因芯片技术筛选肝细胞癌相关基因

目的:探讨基因表达谱芯片技术在筛查肝细胞癌(HCC)相关基因群表达中的作用。方法:TRIzol法抽提2例HCC及正常肝脏组织总RNA,分离纯化两种组织的mRNA;逆转录合成掺入生物素标记的cDNA合成探针,与基因芯片(涵盖了18400个转录本,代表了14 500个明晰的基因)杂交,扫描芯片荧光信号图像,计算机分析,比较2种组织基因表达谱差异。结果:2例HCC组织与正常肝脏组织相比,有2756条基因(19.01%)共同表达差异,其中共同上调基因1772条和共同下调基因984条,对2756条共同差异表达基因作了初步功能分类,这些基因与HCC的发病机制存在相关性。结论:基因表达谱芯片技术可以筛选出HCC表达异常的相关基因群,有助于认识肝癌的发病机制。     

人自身抗原CYP2D6 285 bp基因片段克隆、真核表达及免疫性鉴定

目的:真核表达人自身抗原细胞色素P450 2D6(CYP2D6)显性表位285 bp基因片段,获得具免疫学活性的纯化重组蛋白,为自身免疫性肝炎抗体的检测提供特异性抗原．方法:以肝脏的cDNA混合文库为模板作 PCR,将PCR产物与真核表达载体pEGH共同转化酿酒酵母Y258,碱裂解法进行质粒制备, PCR扩增鉴定．表达载体构建成功后,在半乳糖的诱导下表达产生重组融合蛋白,利用 GST亲和层析法进行纯化．然后对其产物进行十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS- PAGE)和蛋白质印迹法(WB)及蛋白质质谱学 (MALDI-TOF)检测．结果:PCR产物约290 bp,与预期285 bp接近． pEGH-CYP2D6重组阳性克隆PCR鉴定与预期大小接近,SDS-PAGE和WB结果显示,融合蛋白Mr37 000,具有天然人自身抗原CYP2D6 的免疫原性．质谱蛋白肽指纹数据通过Mascot 在人类蛋白质数据库中分析比对,与CYP2D6 蛋白同源性最高．结论:成功克隆表达人自身抗原CYP2D6的显性表位,为建立新的自身免疫性肝炎抗体检测方法奠定了基础．