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)

DNA polymerase [EC 2.7.7.7] activities present in hypotonic extract from rat ascites hepatoma AH130 cells were eluted in three separable peaks on DEAE-cellulose column chromatography. Peak I activity had an alkaline pH optimum, and was relatively resistant to SH-blocking reagents and salt concentration. These properties of DEAE peak I are typical of low molecular weight DNA polymerase. DEAE peak II and peak III activities possessed properties corresponding to high molecular weight (6-8 S) polymerase; they showed maximal activity at neutral pH, and were sensitive to SH-blocking reagents and salt. No low molecular weight polymerase activity was released from DEAE peak II or peak III by salt treatment, though partial conversion from DEAE peak II to peak III was observed on the same treatment.
 ...
PMID:Studies on the molecular species of DNA polymerase extracted from rat ascites hepatoma cells. 0 55

The gamma-glutamyltransferase (EC 2.3.2.2) (=gamma-glutamyltranspeptidase, gamma-GTP) activity in hepatoma induced by 3'-methyl-4-(dimethylamino)azobenzene (3'-Me-DAB) was 120-fold higher than that of normal liver and high activity was also found in bovine hepatocellular carcinoma. gamma-GTPs from these malignant tissues responded more and showed broader specificity to gamma-glutamyl group acceptors than those from normal tissue such as bovine, rat, and mouse liver and bovine kidney. Three species of gamma-GTP were isolated from bovine kidney by DEAE-cellulose chromatography, whereas only two species were isolated from bovine hepatocellular carcinoma. The carcinoma lacked the least acidic enzyme species. Appropriate gamma-glutamyl group acceptors stimulated more-acidic enzyme species more than less-acidic species in both tissues. The fractions separated from the hepatoma were stimulated more than those of kidney by gamma-glutamyl group acceptor. The enzymes from normal tissues responded similarly to a gamma-glutamyl group acceptor irrespective of the difference in their activity. Thus, gamma-GTPs of malignant tissues appear to be more versatile for amino acid transport, both qualitatively and quantitatively. In these properties the enzyme of mouse fetal liver which showed the highest activity in the last period of pregnancy resembled the enzymes of malignant rather than normal tissues. The activity of hepatic gamma-GTP is not parallel with the rate of cell proliferation during normal development.
 ...
PMID:Higher transpeptidation activity and broad acceptor specificity of gamma-glutamyltransferases of tumors. 0 27

Asparagine synthetase (L-aspartate:ammonia ligase (AMP-forming, EC 6.3.1.1) activity in rat liver increased when the animals were put on a low casein diet. The enzyme was purified about 280-fold from the supernatant of rat liver homogenate by a procedure comprising ammonium sulfate fractionation. DEAE-Sepharose column chromatography, and Sephadex G-100 gel filtration. The optimal pH of the enzyme was in the range 7.4-7.6 with glutamine as an amide donor. The molecular weight was estimated to be approximately 110,000 by gel filtration. Chloride ion was required for the enzyme activity. The apparent Km values for L-aspartate, L-glutamine, ammonium chloride, ATP, and Cl- were calculated to be 0.76, 4.3, 10, 0.14, and 1.7 mM, respectively. The activity was inhibited by L-asparagine, nucleoside triphosphates except ATP, and sulfhydryl reagents. It has been observed that the properties of asparagine synthetase from rat liver are not so different from those of tumors such as Novikoff hepatoma and RADA 1.
 ...
PMID:Purification and properties of asparagine synthetase from rat liver. 2 63

A method for the purification of human alpha1-fetoprotein from the ascites fluid of a hepatoma-bearing patient is described that is capable of yielding large quantities of pure alpha1-fetoprotein within a relatively short period of time. The technique is based entirely on the physicochemical properties of the alpha1-fetoprotein molecule and uses sequential purification steps: ion-exchange chromatography on DEAE-Sephadex A-50, molecular-sieve chromatography on Sephadex G-200, negative-affinity chromatography on Sepharose-Blue Dextran, positivepaffinity chromatography on concanavalin A-Sepharose and, finally, molecular-sieve chromatography on Sephadex G-100. The efficiency of the entire procedure in its present form is 15% of the alpha1-fetoprotein activity of the starting preparation from ascites fluid. The purity of the final product was shown by polyacrylamide gel electrophoresis, radioimmunoelectrophoresis, and determinations of the NH2-terminal and COOH-terminal amino acid residues of the alphs1-fetoprotein isolated. Amino acid analysis of the final product revealed a composition very similar to those reported for alpha-fetoprotein preparations that have been previously isolated by the use of immunochemical technology.
 ...
PMID:Physicochemical approach to the purification of human alpha1-fetoprotein from the ascites fluid of a hepatoma-bearing patient. 7 14

DNA was isolated from livers of the rats treated with DAB during various steps of hepatoma development. After histological examination the tumor tissue was separated from the normal liver tissue and used as the source of DNA. Chromatographic fractionation on DEAE and Ecteola celluloses shows characteristic patterns for DNA isolated at various steps of hepatoma development. The largest differences in hepatoma DNA as compared to normal liver DNA were demonstrated in the DNA fraction eluated with 2.0 M-NaCl and NH3, gradient 0.1--1.0 M (m. w. 2--9 x 10(6)), and an increase in the first DNA fraction (m. w. less than 1 x 10(6)) was observed. Differences in the chromatographic patterns are discussed in terms of direct DAB action on DNA.
 ...
PMID:Chromatographic pattern of DNA isolated from liver tissue during hepatoma development. 11 86

Myosin has been purified from the following cultured cell lines: normal rat kidney fibroblast (NRK), HeLa-Rhino (HeLa), human choriocarcinoma, human acute lymphoblastic leukemia, rat hepatoma (HTC), monkey kidney (VERO), pigmented mouse melanoma, Y-1 rat adrenal cortex, and growth hormone-secreting GH-1. Myosin constitutes 0.5-5.4% of the protein of these cells. It was not detected in washed human erythrocytes or in two types of mouse plasmacytoma cells. Two methods for the purification of myosin from cultured cells have been employed. With Method I highly purified myosin was prepared by Sepharose 4B and DEAE-cellulose chromatography from 10(10) L-929 cells as well as from mouse uterus. Those myosins have similar molecular and subunit weights as well as ATPase activity but are immunologically distinct. Method II involving ultracentrifugation and Sepharose 4B chromatography, is suitable for the production of moderately pure myosin in good yield from as few as 5-10(7) cells (five 100-mm Petrie dishes).
 ...
PMID:The purification and quantitation of myosin from cultured cells. 13 88

Activities of hexokinase isozymes in carbon tetrachloride (CCl(4))-injured rat liver were determined quantitatively by DEAE-cellulose column chromatography and compared with those of regenerating liver, fetal liver and ascites hepatoma cells (AH 130). The CCl(4)-injured liver revealed an isozyme distribution with predominant Types I, II and III (3.2, 8.8 and 6.8 times higher than the control values, respectively) and with undetectable activity of Type IV hexokinase (glucokinase). Although the isozyme pattern generally resembled that of fetal liver or hepatoma cells, the relatively high activity of hexokinase Type III in CCl(4) treatment characterizes the pattern of hexokinase isozyme in acue liver damage.
 ...
PMID:Hexokinase isozyme pattern in CCl(4)-injured rat liver. 16 18

Extracts of Novikoff hepatoma cells contain factors capable of stimulating in vitro DNA synthesis several fold. The activity can be resolved into three separate protein peaks on DEAE-Sephadex. Two of these, factors II and III, have been purified and partially characterized. Both factors increase the initial rate of DNA synthesis and allow synthesis to proceed much longer. If either factor is added after synthesis by the DNA polymerase has reached a plateau, resumption of synthesis occurs. The factors appear to have different modes of action or sites of action since they show an additive effect even when a single one is used at saturating conditions. These factors are present in normal rat liver but at a concentration less than 5% of that found in the tumor cells. When tested with several highly purified DNA polymerases (DNA nucleotidyltransferase, EC 2.7.7.7), the factors show a much greater stimulation of homologous, non-mitochondrial enzymes (rat liver nuclear-, rat liver cytoplasmic-, or Novikoff-DNA polymerases) when compared with rat liver or calf liver mitochondrial-, Escherichia coli I-, or sea urchin nuclear-DNA polymerases. The mechanism of action of these factors is not known at present. No enzymatic activity has been associated with factor III. Highly purified, but not homogeneous, preparations of factor II contain low levels of endonuclease; it has not been established whether endonuclease is a contaminant or is responsible for the stimulating activity.
 ...
PMID:Stimulation of DNA polymerase by factors isolated from Novikoff hepatoma. 16 86

RNA sulfurtransferase activity has been detected in rat liver and in hepatomas from rats fed a diet containing 0.06% 3'-methyl-4-dimethylaminoazobenzene for 14 to 18 weeks. The reaction measured was the transfer of sulfur from cysteine to acceptor sites in Escherichia coli B transfer RNA (tRNA). Specific activities of the enzymes in liver and hepatoma supernatant fractions were similar, as were the rates and extents of sulfur transfer to tRNA. DEAE-cellulose chromatography of digests of the [35S]tRNA reaction products revealed 3 peaks associated with nucleotide material, the amounts of these peaks differing in tRNA from liver and hepatoma systems. This may suggest differences in specific sulfurtransferases in these tissues.
 ...
PMID:RNA sulfurtransferase activity in rat liver and chemically induced hepatomas. 17 28

The synthesis of ribosomal precursor RNA in Novikoff hepatoma (N1S1) cells is very sensitive to cordycepin (3'-dA). The synthesis of hnRNA, however, is resistant to inhibition concentrations of 3'-dA that completely block the synthesis of 45S ribosomal RNA precursor. We have examined the RNA polymerases present in these cultured cells with regard to their sensitivity to cordycepin 5'-triphosphate (3'-dATP) in an effort to explain the differential inhibition of RNA synthesis observed in vivo. RNA polymerases I and II were characterized on the basis of their chromatographic behavior on DEAE-Sephadex, as well as the response of their enzymatic activities to ionic strength, the divalent metal ions Mn2+ and Mg2+, and the toxin alpha-amanitin. For both enzymes the inhibition of in vitro RNA synthesis by 3'-dATP was competitive for ATP. The km values for ATP and the K1 values for 3'-dATP for the two enzymes were quite similar. RNA polymerase II, the enzyme presumed responsible for hnRNA synthesis, was actually slightly more sensitive to 3'-dATP than RNA polymerase I, the enzyme presumed responsible for ribosomal precursor RNA synthesis. Similar data were obtained when the RNA polymerases were assayed in isolated nuclei. These results indicate that the differential inhibition of RNA synthesis caused by 3'-dA in vivo cannot be simply explained by differential sensitivity of RNA polymerases I and II to 3'-dATP.
 ...
PMID:The sensitivity of RNA polymerases I and II from Novikoff hepatoma (N1S1) cells to 3'-deoxyadenosine 5'-triphosphate. 17 30


1 2 3 4 5 6 7 8 9 10 Next >>