Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0019204 (hepatocellular carcinoma)
 71,386 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A routine screening test used in the diagnosis of hepatitis C virus (HCV) infection is the anti-HCV antibody (anti-HCV) test containing core, NS3, NS4, and NS5 antigens of HCV. When HCV infection occurs in immunocompromised hosts, antibody formation against core, NS3, or NS4 antigens may be weak in the presence of HCV viremia and cannot be detected by routine anti-HCV tests. This study proposed that in immunocompromised hosts such as patients with chronic renal failure (whose capacity to form antibodies is diminished), antibody formation against the E2 region would be preserved, because the E2/NS1 region of HCV is strongly immunogenic. The aim of this study is to evaluate the significance of anti-E2 in the diagnosis of HCV infection among patients on maintenance hemodialysis who are anti-HCV-negative, using a conventional third-generation enzyme immunoassay (EIA) kit. The E2/NS1 gene of HCV encoding the amino acid sequence 388-664 was molecularly cloned into a vector containing an SV 40 promotor and was expressed in Chinese Hamster ovary cells. Using this E2 protein, the anti-E2 test was performed by EIA on 100 patients on maintenance hemodialysis, and on 50 patients with chronic hepatitis C who were anti-HCV-positive, to evaluate the antigenecity of the E2 protein. Of the 100 hemodialysis patients, 15 (15.0%) tested anti-HCV-positive using a third generation anti-HCV ELISA kit. Of the 85 patients who tested negative for anti-HCV, nine (10.6%) were anti-E2-positive and six (66.7%) of these anti-E2 positive patients showed HCV RNA viremia by HCV reverse transcription-polymerase chain reaction. Fourty-two (84.0%) of 50 patients with chronic hepatitis C were anti-E2-positive. As a control group, we tested for anti-E2 among 30 blood donors who were anti-HCV-negative, and also among 85 patients with hepatocellular carcinoma who were anti-HCV-negative, but in both groups, none (0%) was anti-E2-positive. In conclusion, these data suggest that the E2 protein of HCV should be included in a diagnostic anti-HCV kit for the detection of HCV infection in immunocompromised patients.
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PMID:Significance of anti-E2 in the diagnosis of HCV infection in patients on maintenance hemodialysis: anti-E2 is frequently detected among anti-HCV antibody-negative patients. 895 33

Recent findings suggest that over-expression of activated H-ras inhibited apoptotic cell death by blocking the activity of apoptotic endonuclease(s). This study was designed using antisense H-ras oligodeoxynucleotides (ODN) to evaluate whether alterations of H-ras expression in BEL-7402 human hepatocellular carcinoma cells could influence the induction of apoptosis in vitro and in vivo. We found that, in vitro, continuous suppression of H-ras expression could decrease the proliferation of BEL-7402 cells and inhibit H-ras-induced entry into S phase. In situ end labeling showed that a large number of cells underwent apoptotic cell death after treatment with antisense H-ras ODN (P < 0.01), and gel electrophoresis of DNA extracted from these cells demonstrated a typical DNA ladder, characteristic of apoptosis. In vivo study indicated that pretreatment with antisense H-ras significantly retarded tumor growth in comparison with the untreated controls or tumors treated with non-specific ODN (P < 0.01, P < 0.01). In situ end-labeling revealed that pronounced apoptotic nuclei were also present in the tissue treated with antisense H-ras ODN (P < 0.01). Immunocyto-histochemical study showed that expression of p21H-ras was significantly decreased after treatment with antisense H-ras. These results indicate that suppression of H-ras over-expression by antisense ODN could effectively inhibit tumor growth and revive the apoptotic pathway by releasing the activity of apoptotic endonuclease(s). The data also suggest the need for further studies to elucidate molecular events involved in antisense H-ras-released apoptosis and evaluate its therapeutic implications.
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PMID:Apoptosis of human BEL-7402 hepatocellular carcinoma cells released by antisense H-ras DNA--in vitro and in vivo studies. 899 37

In order to test the controversially discussed hypothesis that oval cells are part of a liver stem cell compartment and can give rise to cholangiocellular as well as hepatocellular carcinomas in the course of liver carcinogenesis, we transfected an oval cell line established in our laboratory with an oncogenically activated genomic Ha-ras clone (pUC EJ 6.6), carrying a valine at position 12 instead of the wild-type glycine, or a rat p53 cDNA mutated by site-directed mutagenesis at codon 247, which corresponds to codon 249 in the human p53. This codon is of particular interest since it represents a mutation hotspot observed in hepatocellular carcinoma especially in regions with high aflatoxin B1 exposure. Independent Ha-rasVal12 and p53Ser247 recombinant clones were subcutaneously injected into syngeneic newborn rats and the resulting tumours were analysed histopathologically. Each of two p53Ser247 clones gave negligible tumour yields (one tumour out of 13 injected animals), whereas each of two Ha-rasVal12 clones gave marked tumour yields (four tumours out of 13 and seven out of 12 treated animals, respectively). In addition, the p53Ser247-induced tumours appeared only after 11 months and were small, whereas the Ha-rasVal12-induced tumours appeared already after 6-8 weeks and grew rapidly. Histopathological analysis of the tumours revealed only undifferentiated carcinomas. Interestingly, one tumour that arose upon injection of Ha-rasVal12-transfected cells stained positive for albumin, showing at least a partial hepatocytic differentiation.
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PMID:Ha-rasVal12 but not p53Ser247 leads to a significant neoplastic transformation rate of the putative rat liver stem cells (oval cell). 900

We tested HGV RNA in serum in addition to HBV DNA and HCV RNA to study the causative agents involved in chronic non-B, non-C hepatitis. Twenty five patients diagnosed as having chronic non-B, non-C hepatitis(negative for HBsAg and HCV-Ab), were investigated in this study. HGV RNA was detected by nested RT-PCR using primers in 5'-untranslated, NS3 and NS5 regions. Of the 25 patients, 4(16%) were positive for HGV RNA, only 1(4%) was positive for HBV DNA and none were positive for HCV RNA. Of the 4 patients with HGV RNA, 2 histologically has mild fibrosis and the remaining 2 had cirrhosis. One patient with cirrhosis also had hepatocellular carcinoma; HBV DNA was positive in this patient. All 3 patients with only the HGV infection had a mild histological grade. In conclusion, HGV infection was involved in 16% of Japanese patients with chronic non-B, non-C hepatitis. Chronic hepatitis G seemed to exhibit mild hepatitis activity.
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PMID:[GB virus C/hepatitis G virus infection in patients with chronic non-B, non-C hepatitis]. 908 58

1(S),3(R)-dihydroxy-20(R)-(5'-ethyl-5'-hydroxy-hepta-1'(E),3' (E)-dien-1'-yl)-9,10-secopregna-5(Z),7(E),10(19)-triene (EB1089) is a novel synthetic analog of 1 alpha,25-dihydroxyvitamin D [1,25-(OH)2D3] with potential for use in the treatment of hyperproliferative disorders. It has an altered side-chain structure compared to 1,25-(OH)2D3, featuring 26,27 dimethyl groups, insertion of an extra carbon atom (24a) at C-24, and two double bonds at C-22,23 and C-24,24a. In vitro metabolism of EB1089 was studied in a human keratinocyte cell model, HPK1A-ras, previously shown to metabolize 1,25-(OH)2D3. Four metabolites were formed, all of which possessed the same UV chromophore as EB1089, indicating the retention of the side-chain conjugated double bond system. Two metabolites were present in sufficient quantities to identify them as 26-hydroxy EB1089 (major product) and 26a-hydroxy EB1089 (minor product), based on mass spectral analysis and cochromatography with synthetic standards. Similar metabolites were generated in vivo and using a liver postmitochondrial fraction in vitro (Kissmeyer et al., companion paper). Studies with the human hepatoma Hep G2 gave rise to 2 isomers of 26-hydroxy EB1089. Studies using ketoconazole, a general cytochrome P450 inhibitor, implicated cytochrome P450s in the formation of the EB1089 metabolites. COS-1 transfection cell experiments using vectors containing CYP27 and CYP24 suggest that these cytochrome P450s are probably not involved in 26- or 26a-hydroxylation of EB1089. Other experiments that examined the HPK1A-ras metabolism of related analogs containing only a single side-chain double bond: 1(S),3(R)-dihydroxy-20(R)-(5'-ethyl-5'-hydroxy-hepta-1' (E)-en-1'-yl)-9,10-secopregna-5(Z),7(E),10(19)-triene (MC1473; double bond at C-22,23) and 1(S),3(R)-dihydroxy-20(R)-(5'-ethyl-5'-hydroxy-hepta-3'(E)-en-1'-yl)-9, 10-secopregna-5(Z),7(E),10(19)-triene (MC1611; double bond at C-24,24a) revealed that the former compound was subject to 24-hydroxylation and the latter compound was mainly 23-hydroxylated. Metabolism experiments involving EB1089, MC1473, and MC1611 in competition with [1 beta-3H]1,25-(OH)2D3 in HPK1A-ras confirmed that CYP24 is probably not involved in the metabolism of EB1089 whereas, in the case of MC1473 and MC1611, it does appear to carry out side-chain hydroxylation. Our interpretation is that the conjugated double bond system in the side-chain of EB1089 is responsible for directing the target cell hydroxylation to the distal positions, C-26 and C-26a. We conclude that EB1089 is slowly metabolized via unique in vitro metabolic pathways, and that these features may explain the relative stability of EB1089 compared to other analogs in vivo.
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PMID:Metabolism of the vitamin D analog EB1089 by cultured human cells: redirection of hydroxylation site to distal carbons of the side-chain. 911 99

Prevalence of hepatitis G virus (HGV) was determined in a cohort of Chinese blood donors and hepatitis patients by the detection of viral RNA via reverse transcription-polymerase chain reaction. While HGV RNA was detected in only 1 of 150 healthy volunteers, the detection rate among professional blood donors was surprisingly high (21/265, 7.9%), and plasmapheresis was identified as a significant risk factor in this population. It was also shown that an elevated serum alanine aminotransferase level is not a reliable marker for HGV infection. Prevalences of HGV in patients with hepatitis C, with non-A-E hepatitis, and with hepatocellular carcinoma were relatively low (8.2%, 16.7%, and 6.1%, respectively). Striking sequence homology (>90%) shared by 5 HGV cDNA clones implicated that they belonged to the same genotype. Phylogenetic analysis of a 446-bp NS3 cDNA confirmed that this genotype was closely related to the prototype viruses.
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PMID:Prevalence and genotype of hepatitis G virus in Chinese professional blood donors and hepatitis patients. 912 92

2,6-di(2,3-epoxypropoxy)xanthone (EPX), a newly synthesized xanthone derivative, is a potent antitumor agent, which is more cytotoxic than the antitumor drug mytomycin C. EPX also demonstrated stronger growth inhibition to T24 (bladder carcinoma with Ha-ras gene mutation) and 212 cells (a NIH/3T3 derivative, transformed by Ha-ras oncogene) than to PLC/PRF/S (hepatoma with normal Ha-ras gene) and NIH/3T3 cells. The preferential repression of EPX on the cell proliferation of 212 and T24 cells was further demonstrated by decreasing Ha-ras oncogene expression levels while EPX dosage increased. The drug concentrations for 50% inhibition (IC50) of cell growth, DNA synthesis Ha-ras oncogene expression and colony formation of T24 and 212 cells are in the same range and lower than the values for RNA and protein synthesis. Moreover, EPX irreversibly reversed 212 cell morphology from a transformed phenotype to a normal one. These data indicate that EPX probably suppresses tumor cell proliferation by inhibiting DNA synthesis and reverses the transformed properties by suppressing Ha-ras gene expression. The mechanisms of biochemical action and cytotoxicity of EPX remain to be determined. However, our data suggest that the EPX-mediated inhibition of cell proliferative capacity of 212 and T24 cells was preceded by a selective down-regulation of Ha-ras oncogene RNA levels. EPX may have the potential to be used broadly against diverse tumors or specifically against Ha-ras oncogene initiated malignancy.
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PMID:Antitumor effect of 2,6-di(2,3-epoxypropoxy)xanthone on tumor cell lines. 913 57

Results from a recent study of ours have demonstrated the significant role of the wild-type ras gene in the development of hepatocellular carcinoma in rasH2 mice having prototype human c-H-ras genes. Chronic cell death and regeneration have been considered to work as co-carcinogens with wild-type ras gene overexpression in this model. To elucidate a role of gene overexpression in the occurrence of chronic inflammation, we tried to induce inflammation in the liver of rasH2 mice by immunizing them with the supernatant of a freshly prepared syngenic liver homogenate. Immunization resulted in a dense inflammatory infiltrate in the portal tract and focal necrosis with spots of fatty or foamy degeneration in the transgenic mouse liver; however, these observations were less frequently observed in non-transgenic mouse liver. Monocytes, granulocytes and plasma cell infiltration were observed in the livers of transgenic mice. An immunohistochemical study showed that CD3-positive lymphocytes also infiltrated the liver. The inflammatory infiltrate was still present in the transgenic liver 24 weeks after the last injection, but little infiltrate was observed at the same time in non-transgenic mice. No hepatic tumours could be produced over the 6 months duration of the study and the results are only preliminary. However, these results do suggest that overexpression of wild-type ras is partially responsible for the occurrence of autoimmune chronic hepatitis.
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PMID:Susceptibility of experimental autoimmune hepatitis in transgenic mice overexpressing the c-H-ras gene. 919 73

In order to explore whether platelet-derived growth factor (PDGF) is involved in hepatocarcinogenesis, expression of PDGF-beta chain and ras P21 were investigated using immunohistochemical method in hepatocarcinoma induced with diethylnitrosamine (DENA). Elevated PDGF-beta chain and P21 protein levels were found in hepatocytes in the early stages after DENA administration. Along with the progression of hepatocarcinogenesis, immunopositive cells were increased with the formation of various foci and nodules and the staining was usually stronger in the peripheral parts of nodules. In addition, PDGF-beta and P21 often expressed simultaneously in the smae lesions, where the cells were also positive for AFP expression. The results suggest that abnormal expression of PDGF might be an early specific event during hepatocarcinogenesis and might be involved in the malignant transformation of the hepatocytes by autocrine as well through ras P21 signal pathways.
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PMID:[The role of platelet-derived growth factor and ras P21 in experimental hepatocarcinogenesis]. 920 9

Hepatic tumors including hepatocellular carcinoma were generated by carbon tetrachloride in transgenic mice carrying a human c-H-ras gene (rasH2 mice). RasH2 mice express 2 to 3 times more ras protein (ras p21) in the liver than do non-Tg mice. When carbon tetrachloride was administered, the rasH2 mice produced about 5 times as many hepatic tumors than did the non-transgenic mice. However, neither the 10-100 times higher ras p21 expression required for murine fibroblast transformation by itself nor the mutational activation of the H-ras gene was observed in carbon tetrachloride-induced hepatic tumors. These results show that H-ras proto-oncogene expression in the murine liver, even if it is not high enough to transform cells, also causes liver tumors when CC1(4) are repeatedly given.
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PMID:Role of H-ras gene in chronic liver damage in mice. By using transgenic mice carrying a human C-H-ras proto-oncogene without mutations. 923 36


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