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

Hypercitrullinemia (adult type), believed to be one of the hereditary urea cycle disorders, is known to be complicated by hepatocellular carcinoma at a high incidence (approximately 14%). We investigated the relationship between this hypercitrullinemia and hepatocarcinogenesis. After the addition of citrulline, incorporation of tritiated thymidine into primary cultured hepatocytes of adult rat increased in a dose-dependent fashion in the range of 0.1 to 5 mmol/L. The citrulline-added group also showed significant increase in ornithine and polyamine contents in hepatocytes. The incidence of epithelial cell foci in the in vivo-in vitro tumor promotion analyzing system significantly rose in the group maintained with 5 mmol/L citrulline and in the group maintained with 1.5 mmol/L phenobarbital. These findings suggest the possibility that citrulline has a promotion effect on hepatocyte proliferation and that at high concentrations it plays the role of a hepatocarcinogenesis promoter.
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PMID:Promoting effect of citrulline in hepatocarcinogenesis: possible mechanism in hypercitrullinemia. 234 56

We have investigated the structure of solubilized cytokeratins from Novikoff ascites hepatoma using the cleavable cross-linker 3,3'-dithiobis(sulfosuccinimidyl propionate) in the presence of 6 M urea to effect partial complex melting. By two-dimensional gel electrophoresis, in which the protein cross-links were broken in the second dimension, we have identified two major complexes as a p39-p56 dimer and a (p39-p56)2 tetramer, p39 and p56 being two of the major cytokeratins in Novikoff ascites hepatoma. Experiments investigating possible relationships between the dimer and tetramer employed immunoblots and two monoclonal antibodies which recognized either p56 or p39 cytokeratins. When very low protein concentrations were cross-linked, the dimer was the predominant product. As protein concentration increased, we noted a decrease in dimers and a corresponding increase in tetramers, suggesting that the dimer may be a precursor to the tetramer. In support of the cross-linking experiments, two-dimensional gel electrophoresis using 4 M urea in the first dimension indicated a predominant association of p56 and p39 in the Novikoff ascites hepatoma cytokeratin complexes.
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PMID:Cross-linking of Novikoff ascites hepatoma cytokeratin filaments. 241 87

Three monoclonal antibodies against human liver ferritin were selected to study antigenic determinants (epitopes) of human isoferritins. These monoclonal antibodies were found to form immunoprecipitin lines with ferritin in double diffusion tests (Ouchterlony), indicating multiple epitopes on a single ferritin molecule. The antibodies revealed high species specificity as well. Monoclonal antibodies MA301 and MA311 appeared to recognize different epitopes, since they did not inhibit each other in competitive enzyme-linked immunosorbent assay (ELISA). However, MA309 recognized both epitopes for MA301 and MA311 with similar competitive inhibition. These epitopes were not detectable when ferritin was treated with 8M urea (pH 2.5) and were detectable upon reconstruction by dialysis against 2 M urea (pH 7.2), suggesting that these monoclonals recognize epitopes in the tertiary structure of the ferritin molecule. As a matter of fact, these monoclonals react preferentially with intact ferritin molecule and only negligibly with subunits. Isoelectric focusing patterns of human ferritins demonstrated that liver, spleen, placenta, and hepatoma cells (Li-7) transplanted in nude mice contained basic isoferritins, whereas HeLa cells (carcinoma), Wa cells (EB virus-transformed B cells), and Raji cells (Burkitt's lymphoma) contained acidic isoferritins. Human heart ferritin displayed a somewhat intermediate pattern between liver and HeLa ferritins. In spite of the heterogeneous population of human isoferritins, the dissociation constants (Kd) of the three monoclonal antibodies to liver, HeLa, and heart isoferritins were quite similar.
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PMID:Common epitopes in human isoferritins characterized by murine monoclonal antibodies. 242 Jul 86

Previous studies have documented nuclear insulin accumulation in a variety of cell types. The present investigation extends these observations by demonstrating that insulin associates with the matrix fraction of H35 rat hepatoma cell nuclei. Nuclei were isolated from [125I]insulin-loaded cells and extracted with DNase I, RNase A and high salt. The resulting matrix fraction was found to contain greater than 75% of the radiolabel initially present. Ultrastructural studies to confirm these findings were carried out using an agarose-encapsulated nuclear matrix preparation. Electron microscopic immunocytochemistry specifically detected insulin in matrices prepared from insulin-treated cells. No reaction was observed in matrices obtained from non-insulin-treated (control) cells. Further biochemical analysis revealed that matrix-associated insulin could be solubilized with 1% sodium dodecyl sulfate (SDS) or in the presence of high urea concentrations. Gel filtration analysis of urea-solubilized matrix material revealed the presence of apparently intact [125I]insulin and a higher molecular weight peak. It is hypothesized that the latter may represent a tightly associated complex of insulin with some matrix protein(s).
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PMID:Intranuclear localization of insulin in rat hepatoma cells: insulin/matrix association. 269 59

The urea extract of the glycoproteins from the extracellular matrix of rat liver has been compared with that of Morris hepatoma 7777. A high molecular weight glycoprotein present in Morris hepatoma 7777 was not found in the extract of liver matrix. Under reducing conditions in SDS-gel electrophoresis this component gave two glycoprotein bands with Mr 53 k and 56 k. The indirect immunofluorescence staining with a monospecific antiserum directed against the component showed its abundant presence in Morris hepatoma 7777 as well as in the less malignant Morris hepatoma 9121 in form of extracellular network structures. The antigen also densely filled some cumuli of cells. In contrast the liver tissue showed only very weak staining of the extracellular areas. The overall distribution of the component could be correlated with the distribution of several hydrolases in the tumor matrix, notably beta-D-glucuronidase.
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PMID:Increased expression of a high molecular weight matrix component in rat hepatocellular carcinoma. 282 Sep 9

Rat liver coated vesicle preparations were frequently found to contain small ovoid bodies, which resembled coated vesicles in morphology. We have purified these bodies to homogeneity using sucrose density gradients and preparative agarose gel electrophoresis. When negatively stained and viewed by electron microscopy, the purified structures display a very distinct and complex morphology, resembling the multiple arches which form cathedral vaults. They measure 35 X 65 nm and are therefore considerably larger than ribosomes. When subjected to SDS PAGE, these structures, which we refer to as vaults, appear to contain several minor and five major species: Mr 210,000, 192,000, 104,000, 54,000, and 37,000. One of these (Mr 104,000) greatly predominates, accounting for greater than 70% of the total Coomassie Brilliant Blue-staining protein. Another major species of Mr 37,000 has been identified as a species of small RNA of unusual base composition (adenosine 12.0%, guanosine 29.7%, uridine 30.9%, and 27.4% cytidine), which migrates as a single species in urea PAGE between the 5S and 5.8S ribosomal standards, containing approximately 140 bases. Although the RNA constitutes only 4.6% of the entire structure, the large size of the particle requires that each one contains approximately 9 molecules of this RNA. Antibodies prepared against the entire particle are largely specific for the major (Mr 104,000) polypeptide species. Although they do not directly react with the RNA constituent on Western blots, these antibodies immunoprecipitate a 32P-labeled RNA of identical size from metabolically-labeled rat hepatoma cells. Vaults are observed in partially purified fractions from human fibroblasts, murine 3T3 cells, glial cells, and rabbit alveolar macrophages. It therefore appears that these novel ribonucleoprotein structures are broadly distributed among different cell types. The function of vaults is at present unknown.
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PMID:Isolation and characterization of a novel ribonucleoprotein particle: large structures contain a single species of small RNA. 294 44

The influence of a variety of clinical and biochemical parameters on the activities in serum of ribonuclease (RNAse) selective for polycytidylic acid (RNAse C) were examined in 90 adult patients with cancer. The clinical data base determined on each patient included: RNAse C level, carcinoembryonic antigen (CEA) level, age, sex, race, presence (or absence of metastases, type of cancer, site of metastasis, renal function blood urea nitrogen [BUN], creatinine), hepatic function (bilirubin, alkaline phosphatase), and nutritional status (percent ideal body weight, percent weight loss, and albumin). Common tumor types studied included: colon (21), lung (18), breast (15), and hepatocellular carcinoma (10). For comparison, 175 nonmalignant control patients were studied to establish the normal range for RNAse. In patients with cancer, RNAse levels were increased in 57% and CEA levels were above 10 ng/dl in 36%. Although patients with BUN greater than 25 mg/dl or creatinine greater than 1.5 mg/dl were not entered on the study, nonetheless, RNAse was significantly (P less than 0.05) associated with both BUN and creatinine. Nutritional status also had an important influence on RNAse levels as both percent weight loss and percent ideal body weight were significantly (P less than 0.05) associated with circulatory RNAse: weight loss resulted in higher RNAse levels. These results account in part for the increased RNAse levels seen in those malignant conditions such as pancreatic and lung cancer commonly associated with weight loss in advanced stage. The possibility that circulatory RNAse C determination will provide a sensitive means for assessing nutritional status in cancer patients will require prospective evaluation.
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PMID:Influence of nutritional status on circulatory ribonuclease C levels in patients with cancer. 298 Nov 45

Ornithine transcarbamylase (OTCase) is a mitochondrial matrix enzyme that catalyzes the 2nd step in the mammalian urea cycle. The gene encoding OTCase is located on the X chromosome and expression of OTCase is limited almost exclusively to hepatocytes. We have characterized a lambda phage recombinant, isolated from a mouse genomic library, that spans the first two exons of the mouse OTCase gene. Nuclease S1 mapping and primer extension analysis of this clone allowed us to determine that the transcription start site is 136 base pairs (bp) upstream from the translation initiation codon. Two TATA-like sequences were found 25 and 153 bp from the transcription initiation point. An 800-bp fragment containing the 5' flanking region of the OTCase gene was fused upstream to the coding sequence of the chloramphenicol acetyltransferase gene to assay promoter activity. This plasmid was introduced into mouse fibroblast NIH 3T3 cells and human hepatoma Hep G2 cells by the calcium phosphate co-precipitation method. After DNA transfection chloramphenicol acetyltransferase activity was observed only in Hep G2 cells. We conclude that this 800-bp fragment contains sufficient information to control OTCase gene expression in a tissue-specific manner, probably by interacting with trans-acting factor(s) which are not present in the other cell line.
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PMID:The 5' flanking region of the ornithine transcarbamylase gene contains DNA sequences regulating tissue-specific expression. 301 88

A prognostic study based on 127 untreated patients with hepatocellular carcinoma was undertaken to evaluate their survival time and to find clinical and biologic criteria which allow the selection of patients with a survival time longer than 60 days who could enter a therapeutic trial. Twenty-eight clinical and biologic variables were assessed using univariate and multivariate semiparametric regression (Cox's) models. Ten variables were isolated by univariate analysis. Multivariate analysis found a negative relationship between a survival time longer than 60 days and five of these variables; these variables were in decreasing order: encephalopathy, alcohol consumption, aspartate amino transferase (AST), blood urea nitrogen, and total bilirubin. Prevalence, positive, and negative predictive values of encephalopathy were 20%, 27.5%, and 97% respectively. When three other criteria: ASAT greater than four times the upper limit of the normal (N), blood urea nitrogen greater than N, and total bilirubin greater than 2N were added, their prevalence, positive, and negative predictive values were 72%, 89.7%, and 57.1% respectively. These results suggest that in countries where incidence of hepatocellular carcinoma is low and recruitment of patients difficult, absence of encephalopathy must be the only criterion for selection of patients with hepatocellular carcinoma in therapeutic trials; whereas, in countries with a high incidence of hepatocellular carcinoma the other criteria may be added.
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PMID:Prognostic factors in patients with hepatocellular carcinoma. Attempts for the selection of patients with prolonged survival. 303 3

Soluble interleukin 2 receptors (sIL 2R) in the sera of patients with viral liver diseases were quantified with a solid-phase enzyme immunoassay using two monoclonal antibodies against the receptors. The sIL 2R levels in patients with acute hepatitis, chronic hepatitis, liver cirrhosis and hepatocellular carcinoma were significantly higher than those in control subjects. In acute hepatitis patients, the high levels of sIL 2R observed during the florid stage returned to normal during remission. Levels in patients with chronic active hepatitis were significantly higher than in those with chronic persistent and lobular hepatitis, and levels observed during the exacerbation phase of chronic hepatitis were higher than they were during remission. Thus, in chronic hepatitis, sIL 2R levels increased in proportion to the inflammatory activity, and correlated well with serum transaminase (glutamic oxaloacetic transaminase: SGOT, glutamic pyruvic transaminase: SGPT) activities, but not with blood urea nitrogen or creatinine concentrations. In patients with a high degree of focal and piecemeal necrosis, serum sIL 2R levels increased further during recombinant interleukin 2 therapy. In post-hepatitic liver cirrhosis and hepatocellular carcinoma, sIL 2R levels correlated with serum cholinesterase and creatinine concentrations, but not with transaminase activities. Measurement of serum sIL 2R levels in patients with liver disease but without renal injury, may help in the diagnosis of inflammation in hepatitis, a process in which interleukin 2 may participate.
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PMID:Increased serum soluble interleukin 2 receptor levels in patients with viral liver diseases. 306 11


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