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)

A monoclonal antibody against a membrane glycoprotein of rat hepatocytes has been produced. The nature of this antibody designated as HAM.4 was analysed by cellular radioimmunoassay, flow cytofluorography and indirect immunoperoxidase procedures. The following characteristics of HAM.4 were elucidated. First, an immunohistochemical study revealed that this antibody stained preferentially the bile canalicular face of hepatocyte membrane. Secondly, HAM.4 cross-reacted with kidney, spleen and thymus as well as liver. The kidney expressed much more the antigen molecules detected by this antibody than the liver did. The antigen was located predominantly on the brush border of proximal tubules in kidney. Thus, HAM.4 would be useful for analysing one of the brush border antigens of renal tubules which has been thought to be a pathogenic antigen for inducing experimental membranous glomerulonephritis. Finally, HAM.4 failed to label the cell membrane of rat hepatoma cell lines examined, indicating that the antigen detected by HAM.4 may disappear from cell surface during the course of hepatocarcinogenesis.
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PMID:A monoclonal antibody to a rat hepato-renal membrane antigen. 389 Nov 69

A major glycosphingolipid in rat bone marrow cells was purified, and its structure was studied. The glycolipid was found to exhibit blood group B activity by the hemagglutination inhibition test. The structure was determined to be (formula; see text) by studies of nuclear magnetic resonance, sequential hydrolysis by exoglycosidases, linkage analysis of methylated sugars by gas chromatography-mass spectrometry, and immunological tests. The blood group B active glycolipid was detected not only in the bone marrow cells but also in spleen, thymus, and rat ascites hepatoma AH 7974F cells. Besides the glycolipid, gangliotriaosylceramide, gangliotetraosylceramide, and fucogangliotetraosylceramide were commonly detected in these cells. The similarity between the glycolipid species on the cell surfaces of the immunocytes and the tumor cells is discussed with the respect to an escape mechanism of the tumor cells from the immunosurveillance system.
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PMID:A new type of blood group B active glycosphingolipid in rat bone marrow cells. Occurrence of the glycolipid in rat immunocytes and ascites hepatoma. 399 20

Histones were prepared from isolated nuclei and nucleoli of the Novikoff ascitic hepatoma at several time points after the injection of L-lysine uniformly labeled with C(14) into tumor-bearing rats. Amino acid analysis and starch-gel electrophoresis failed to reveal any differences between the nuclear and nucleolar histones, although both fractions were more acidic in composition than calf thymus histones. However, the nucleolar histones were a metabolically distinct fraction, and their rate of synthesis was approximately twice that of the total nuclear histones.
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PMID:Biosynthesis and composition of histones in Novikoff hepatoma nuclei and nucleoli. 428 58

A non-histone protein was obtained by extraction of nuclei derived from rat liver or thymus or ascites-hepatoma cells with 5% (w/v) HClO(4). Separation from histone F1 was achieved by chromatography on DEAE-cellulose. The purified component P1 was characterized and the formation of complexes with histone F1 and polylysine was studied.
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PMID:The characterization of a non-histone protein isolated from histone F1 preparations. 435 16

The behavior of the activity of 5-phosphoribosyl 1-pyrophosphate (PRPP) synthetase (ribosephosphate pyrophosphokinase, EC 2.7.6.1) was elucidated in normal rat liver, in 11 hepatomas of different growth rates, and in rapidly growing differentiating and regenerating liver. Tissue extracts were prepared by centrifugation of 10% homogenates at 100,000 X g for 30 min, and enzyme activity was measured in the protein fractions obtained by 40 and 47% ammonium sulfate saturation of the supernatant fluids from livers and hepatomas, respectively. In the tissue extracts, there was no interfering enzyme activity that utilized PRPP under the standard assay conditions. The affinity of PRPP synthetase for its substrates, ribose 5-phosphate and adenosine triphosphate (ATP), and to Mg2+ was similar in liver and hepatoma extracts. The Km for ribose 5-phosphate was 0.3 mM; for ATP, it was 0.1 mM in the presence of excess Mg2+. The Km for Mg2+ ATP was 1.2 mM in the presence of excess ATP. There was no difference in the affinity of the enzyme for its activators, Mg2+ and inorganic phosphate, in liver and hepatoma preparations; the Km for Mg2+ was 0.6 mM in the presence of excess ATP; the Km for inorganic phosphate was 14.0 mM. The requirement of hepatoma extracts for full phosphate saturation was higher than that of liver extracts (85 versus 65 mM). A standard assay was worked out for the liver and hepatoma systems; in liver, the enzyme activity was linear for 30 min incubation, and in hepatoma it was linear for 15 min incubation. PRPP synthetase activity was proportionate with amounts of protein added over a range of 0.4 to 3.0 mg in both liver and hepatoma extracts. In the liver of normal adult Wistar rats, PRPP synthetase activity was 108 +/- 10 nmol/hr/mg protein. In rat tissues of high cell renewal activity, thymus, testis, spleen, and small intestine, synthetase specific activity was 3.7-, 3.6-, 1.2-, and 1.3-fold higher than that of normal liver. The synthetase specific activity in hepatomas of slow growth rate increased 1.2- to 1.5-fold, and in intermediate and rapidly growing hepatomas it was elevated 1.9- to 4.1-fold higher than that of normal liver.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Increased 5-phospho-alpha-D-ribose-1-diphosphate synthetase (ribosephosphate pyrophosphokinase, EC 2.7.6.1) activity in rat hepatomas. 609 67

The poly (A)-mRNA fraction isolated by chloroform deproteinization of liver polysomes and poly(U)-Sepharose chromatography contains a low molecular weights (congruent to 1000) peptidic fraction. The peptides which we suggested to call deprimerones (1) were extracted with 80% ethanol at pH 9.5; after ethanol evaporation, they were purified on Sephadex G-25 column as a fraction of mol. wt. between 1600 and 600, yielding about 9 mg/mg mRNA. If deproteinization is performed with phenol-chloroform the yield is about 2 mg/mg mRNA. In Novikoff hepatoma the yield of the same preparation is only 2.7 mg/mg mRNA (about 70% decrease). The obtained deprimerones are active in inhibiting transcription of thymus DNA with E. coli RNA polymerase and [3H]-GTP by about 90% at a ratio peptide/DNA = 2. For comparison the deprimerones obtained previously (2) by extraction of deproteinized DNA inhibit transcription only by about 50% at the same peptide/DNA ratio. The results demonstrated a decrease of the poly (A)-mRNA deprimerone level during carcinogenesis and further support the previously demonstrated specific occurrence of deprimerones with poly(A)-mRNA. They remain in accordance with and provide further support for the deprimerone theory of carcinogenesis postulated earlier (1).
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PMID:Poly(A)-mRNA deprimerones in rat liver and Novikoff hepatoma cells. 610 57

The concentration of L-glutamine was determined in freeze-clamped samples of normal liver of adult male fed rats (5.7-6.1 mumol/g) and in transplantable hepatomas of vastly different proliferative rates. The L-glutamine concentration in the slowly growing hepatomas was in the range of the normal liver and it decreased in relation to the increase of hepatoma growth rate, in the most rapidly growing tumors amounting to 12% of that of normal liver. In 24-hour regenerating liver, the glutamine content was slightly reduced (by 17%). In normal rat organs of high cell renewal, such as testis, intestinal mucosa, spleen, and thymus, the L-glutamine concentration was 18 to 46% of that of normal rat liver. The L-glutamine content was similar in rat brain and liver, but it was 1.6-fold higher in the heart, and low in the blood. Glutamine synthetase (EC 6.3. 1.3) activity in normal adult liver of ACI/N strain rats was 1,000 nmol per hr per mg protein; the activity increased in the very slowly growing hepatoma 20, but decreased markedly in all the other hepatomas. Thus, glutamine synthetase activity was essentially transformation-linked. The negative correlation of glutamine content with growth rate in transplanted hepatomas appears to be more closely linked with the activities of enzymes that utilize glutamine. The low L-glutamine concentration in the rapidly growing hepatomas provides a potential marker for anti-glutamine chemotherapy selectively targeted against the glutamine-utilizing enzymes.
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PMID:Negative correlation of L-glutamine concentration with proliferation rate in rat hepatomas. 614 11

Enhanced nucleocytoplasmic RNA transport has been demonstrated by incubating normal rat liver nuclei in presence of cytosols originating from the poorly differentiated, fast-growing hepatoma HW-165, in the linear phase of tumor growth. The effect of hepatoma HW-165 cytosol was reduced or suppressed in presence of small amounts of normal liver cytosol: on the other hand, several polypeptides of molecular weight 20,000 to 40,000 daltons were hardly detectable in hepatoma HW-165 cytosol, both arguments indicating that potentially regulatory proteins should be absent or present in reduced concentration in hepatoma HW-165 cytosol. No modification of RNA release was observed in presence of cytosols originating from the thymus of RNA virus (BL/F)-infected rats, whatever be the time after inoculation. Attempts were made to use the nuclear restriction assay, supplemented with plasma or serum of various origins, as a biochemical marker of neoplasia. In a first series of assays, including 80 cancer patients and 12 healthy controls, the RNA transport activity was stimulated by the serum of patients bearing various tumors (lung cancer, cancer of the respiratory tract, uterine cervix...), except in a few cases of mammary carcinoma, where values equivalent to or lower than the controls were obtained.
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PMID:On the altered nucleocytoplasmic transport "in vitro" of rapidly labelled RNA, in the presence of cytosol or serum from tumor-bearing rats. 616 10

Cell-specific chromatin antigens have been detected in rat Sertoli cells. Antisera were raised in rabbits to dehistonized chromatin prepared from 5- to 6-day cultures of rat Sertoli cells and immunoreactivity was assessed with microcomplement fixation tests or immunoidentification of antigens separated electrophoretically and transferred to nitrocellulose sheets. Tissue specificity was confirmed further by immunoabsorption. These antisera recognized only components of Sertoli cell chromatin; chromatins prepared from rat liver, kidney, thymus, Novikoff hepatoma, a testes germinal cell fraction, or purified rat DNA showed little or no immunoreactivity. Nitrocellulose transfers of total chromosomal proteins revealed the presence of two high-molecular-weight antigens (greater than 200,000) and a broad range of weaker immunologic species (M tau about 50,000-200,000) in Sertoli cell chromatin but not liver or thymus chromatin. Deproteinization of Sertoli cell chromatin with concentrated salt and urea at pH 6 or 8 produced an increase in complement-fixing activity of the fraction sedimenting with DNA and micrococcal nuclease digestion studies showed these fractions to depend in part on DNA for antigenicity. Individual antigens in the protein-DNA pellets of pH 8 salt and urea fractionated chromatin could not be identified with antigens on nitrocellulose sheets. Collectively, these observations suggest that at least two groups of cell-specific antigens exist in Sertoli cell chromatin; one group is detected after electrophoretic separation and transfer to nitrocellulose and the other group, reactive in complement fixation, cannot be detected through this method, apparently becoming antigenically inactive once the complex of protein and DNA is dissociated.
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PMID:Tissue and cell-specific antigens in chromatin from cultured rat Sertoli cells. 618 1

The phosphorylation of electrophoretically homogeneous preparations of the five major subcomponents of that thymus H1 histone by growth-associated histone kinase isolated from Ehrlich ascites tumor or Novikoff hepatoma cell chromatin results in the introduction of three to six phosphates/molecule into different subcomponents. Fully phosphorylated preparations of subcomponents 1 through 4 consist of H1 molecules containing a uniform number of phosphate groups, and run as single bands in long acid-urea gels. Fully phosphorylated preparations of subcomponent 5 consist of a mixture of molecules containing five and six phosphate groups. Phosphorylation of subcomponents 2, 4, and 5 occurs in both the NH2- and carboxyl-terminal regions of the molecules. Phosphorylation of subcomponents 1 and 3 occurs only in the carboxyl-terminal region. The central globular region of the histones is not phosphorylated. The major sites of phosphorylation in rat H1 histone subcomponents are similar to, but not entirely identical with, the major sites of phosphorylation previously characterized in total calf thymus H1, as determined by comparison of phosphopeptide maps. Highly phosphorylated rat H1 molecules, similar in phosphate content to those found in mitotic cells, have distinct chromatographic properties, compared to lightly phosphorylated molecules of the type found in interphase cells. This change in chromatographic properties appears to depend on the number of phosphate groups present in the histone rather than on the presence of phosphate in any specific sites.
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PMID:Characterization of highly phosphorylated subcomponents of rat thymus H1 histone. 629 83


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