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)

Glucocorticoid hormones specifically increase the intracellular concentration of mouse mammary tumor virus (MMTV) RNA in a cultured cell line from a GR mouse mammary carcinoma (GR) and in an MMTV-infected rat hepatoma cell line (M1.19). In contrast, these steroids have no effect on the concentration of MMTV RNA in a lymphoma line, S49, from a Balb/c mouse. Using a molecular hybridization procedure to detect newly synthesized RNA, we have directly measured the effect of dexamethasone, a synthetic glucocorticoid, on the rate of MMTV RNA synthesis. In GR cells the hormone causes a 10-fold increase in the rate of synthesis of viral RNA without appreciably affecting the overall rate of cellular RNA synthesis. The transition from the basal to the maximally stimulated rate of MMTV RNA synthesis occurs within the earliest labeling period, 0-15 min after addition of the hormone. Thus, it appears that glucocorticoids regulate MMTV genes principally by this rapid and specific alteration of their rate of transcription. Similar results are obtained in M1.19 rat hepatoma cells. In contrast, dexamethasone does not affect the rate of viral RNA synthesis in S49 lymphoma cells.
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PMID:Glucocorticoid-stimulated accumulation of mouse mammary tumor virus RNA: increased rate of synthesis of viral RNA. 19 23

Dexamethasone, a synthetic glucocorticoid, selectively increased the rate of synthesis of mouse mammary tumor virus (MTV) RNA in clonal isolates of chronically infected rat hepatoma tissue culture cells. This hormonal effect occurred extremely rapidly and appeared to be mediated directly by the glucocorticoid-specific receptor protein. In addition to the viral RNA, unintegrated MTV DNA was also detected in these cells. Several lines of evidence are consistent with the idea that the unintegrated viral DNA is synthesized by reverse transcription of MTV RNA. (i) Unintegrated viral DNA accumulated only in the presence of dexamethasone and was produced with a time course that closely paralleled the increased accumulation of viral RNA. (ii) Density labeling of the viral DNA revealed that both strands were newly synthesized, implying a non-semiconservative mode of replication. (iii) Inhibitors of viral RNA synthesis prevented the appearance of unintegrated viral DNA. These data suggest that the production of unintegrated MTV DNA after dexamethasone treatment occurs as a secondary consequence of the hormonal induction of synthesis of viral RNA. In contrast to infected rat hepatoma cells, no unintegrated MTV DNA was detected in mouse mammary tumor cells or mouse lymphoma cells, despite the presence of high levels of viral RNA.
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PMID:Production of unintegrated mouse mammary tumor virus DNA in infected rat hepatoma cells is a secondary action of dexamethasone. 20 32

Adenylate cyclase can be resolved into at least two proteins, a thermolabile, N-ethylmaleimide-sensitive component and a second protein (or proteins) that is more stable to either of these treatments. Neither component by itself catalyzes the formation of cyclic AMP using MgATP as substrate. However, mixture of the two reconstitutes MgATP-dependent fluoride- and guanyl-5'-yl imidodiphosphate (Gpp(NH)p)-stimulatable adenylate cyclase activity. The more stable component can be resolved from the first in various tissues or cultured cells by treatment of membrnes or detergent extracts with heat or N-ethylmaleimide. The two proteins have also been resolved genetically in two clonal cell lines that are deficient in adenylate cyclase activity. An adenylate cyclase-deficient variant of the S49 lymphoma cell (AC-) contains only the thermolabile activity, while the activity of the more stable protein is found in a complementary hepatoma cell line (HC-1). In addition, AC-S49 cell plasma membranes contain MnATP-dependent adenylate cyclase activity. The protein that catalyzes this reaction appears to be the same as that which can combine with the thermostable component to reconstitute Mg2+-dependent enzyme activity because both activities co-fractionate by gel exclusion chromatography and sucrose density gradient centrifugation, both activities have identical denaturation kinetics at 30 degrees C, and both activities are stabilized at 30 degrees C and labilized at 0 degree C by various nucleotides and divalent cations with similar specificity. It is thus hypothesized that the thermolabile factor is the catalytic subunit of the physiological adenylate cyclase and that the Mn2+-dependent activity is a nonphysiological expression of the catalytic protein. The thermostable moiety of the enzyme, which is proposed to serve a regulatory function, appears to consist of two functional components, based upon differential thermal lability of its ability to reconstitute hormone-, NaF-, or Gpp(NH)p-stimulated adenylate cyclase activity. These components have not, however, been physically separated. The thermolabile and thermostable components can interact in detergent solution or in a suitable membrane. Mixing of the detergent-solubilized regulatory component with AC-membranes that contain only the catalytic protein and beta-adrenergic receptors reconstitutes catecholamine-stimulatable adenylate cyclase activity; however, addition of the catalytic protein to membranes that contain receptor and the regulatory component yields MgATP-dependent enzymatic activity that is unresponsive to hormone.
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PMID:Reconstitution of hormone-sensitive adenylate cyclase activity with resolved components of the enzyme. 21 Jan 83

Studies were made to determine if examination with multiple radiopharmaceuticals would improve the sensitivity and specificity of colloid liver spleen scans. Increased uptake of Ga-67 citrate and In-111 bleomycin was found in most Tc-99m sulfur colloid scan defects caused by hepatocellular hepatoma or lymphoma. Increased uptake of these agents was found in some defects caused by malignant melanoma, breast carcinoma and carcinoma of the lung, and was rarely seen in defects caused by cholangiocarcinoma or gastrointestinal neoplasms. Gallium was useful in the followup of patients with hepatoma. Procedures designed to evaluate the gall bladder fossa, renal impression, or blood pool activity of an apparent tumor were found to be helpful and simple to perform. Iodine-131 as NaI was useful in studying functioning liver metastases from thyroid carcinoma as were bone scanning agents in evaluating hepatic metastases from osteogenic sarcoma. Multiple radiopharmaceutical evaluation of the physiologic and biochemical characteristics of liver lesions supplements current radiologic examinations and increases diagnostic specificity.
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PMID:A study of filling defects in the liver and spleen with multiple radionuclides. 21 17

Cholera toxin, using [32P]NAD+ as substrate, specifically radiolabels at least two proteins in plasma membranes of wild type S49 mouse lymphoma cells. The toxin-specific substrates are detectable by sodium dodecyl sulfate-polyacrylamide gel electrophoresis as bands corresponding to molecular weights of 45,000 and a doublet of 52,000 to 53,000. Membranes of two other cell types exhibit similar patterns of radiolabeled bands specifically produced by incubation with cholera toxin: the "uncoupled" variant S49 cell, which possesses adenylate cyclase activity unresponsive to hormones, and the HTC4 rat hepatoma cell, which lacks detectable catalytic adenylate cyclase activity but contains components of the cyclase system necessary for regulation by guanyl nucleotides and NaF. Little or no toxin-specific radiolabeling is observed in membranes of a fourth cell type, the adenylate cyclase activity-deficient S49 variant, which functionally lacks components of the cyclase system involved in cholera toxin action and regulation by guanyl nucleotides and NaF. The toxin-specific labeling pattern is not observed in membranes prepared from wild type S49 cells previously treated with cholera toxin in culture. One or both of the toxin substrates thus appears to be involved in regulation of adenylate cyclase by guanyl nucleotides and fluoride ion.
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PMID:Genetic evidence that cholera toxin substrates are regulatory components of adenylate cyclase. 21 17

Uridine kinase activities were found chiefly in the soluble fractions of rat tissues. In normal adults the activities ranged from 13 munits/g in skeletal muscle to 178 munits/g in colon. Enzyme activities in several rat neoplasms were significantly higher (e.g. in a fibrosarcoma, mammary carcinoma, renal carcinoma, pancreatic carcinoma and lymphocytic lymphoma, but not in a fast-growing Morris hepatoma). The activities were not related to tumour growth rates or sizes. In normal foetal liver, lung, brain, heart and kidney, uridine kinase concentrations equalled or exceeded those in the adult homologous tissue, but maximal activities in liver were reached 3--5 days post partum. In suckling rats the intestinal activity decreased substantially immediately after birth and normally did not rise again until late in the third postnatal week. Premature upsurges could be evoked by an injection of cortisol or by starvation of the pups overnight. Pancreatic activity was absent from 1-day-old rats, and only about 5% of the adult activity was reached by day 20; adult activities were attained rapidly after weaning. In pancreas, precocious formation or uridine kinase was elicited by overnight starvation of 2-week-old rats.
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PMID:Uridine kinase activities in developing, adult and neoplastic rat tissues. 22 27

Serum carcinoembryonic antigen (CEA) concentration was found to be raised in 503 of 550 patients (91%) with bladder cancer, lymphoma of intestine, hepatocellular carcinoma, bronchogenic carcinoma, prostate cancer, cirrhosis of liver and bilharziasis. The degree of elevation was moderate in all patients except in 189 patients in whom values more than 20 ng/ml were recorded, of which 53 patients with bladder cancer and 118 patients with bilharziasis. The mean CEA value in the patients with cirrhosis in the non-tumorous liver was slightly higher than that in those without cirrhosis, but the difference did not reach statistical significance (P greater than 0.01). There was no correlation between serum CEA and alph-fetoprotein (AFP) levels in all patients except in patients with bladder carcinoma, hepatoma and bilharziasis.
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PMID:Carcinoembryonic antigen (CEA) in patients with malignant and non-malignant diseases. 23 Apr 22

Adenylate cyclase can be resolved into at least two protein components, neither of which by itself catalyzes the formation of cyclic AMP with Mg-ATP as substrate. Mixture of the two reconstitutes Mg-ATP-dependent, fluoride- and Gpp(NH)p-stimulable activity. One, a heat-labile, N-ethylmaleimide-sensitive protein of molecular weight 190,000 can catalyze cyclic AMP formation with Mn-ATP as substrate, and is therefore proposed to be the catalytic moiety of the adenylate cyclase complex. The other protein (or proteins) is more resistant to heating or N-ethylmaleimide, and is proposed to confer upon the catalyst the ability to ultilize Mg-ATP as substrate. It is also required for the regulation of that activity by guanine nucleotides, hormones, and probably fluoride ion. The catalytic protein is found in a phenotypically adenylate cyclase-deficient (AC-) variant of S49 lymphoma cells. The thermostable regulatory protein can be resolved from the catalyst by heat treatment or N-ethylmaleimide treatment of plasma membranes of wild-type S49 cells, rat or rabbit liver, or avian erythrocytes, and is also found in a phenotypically adenylate cyclase-deficient hepatoma cell line. Mixture of AC- S49 membranes, which contain the beta-adrenergic receptor, with a crude detergent-solubilized preparation of the regulatory protein reconstitutes hormone-stimulable adenylate cyclase activity. Binding of the regulatory protein to the membranes is a time- and temperature-dependent process that requires an activating ligand of the adenylate cyclase system [fluoride, Gpp(NH)p].
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PMID:Identification and partial characterization of some components of hormone-stimulated adenylate cyclase. 23 86

Familial non-Hodgkin lymphoma (NHL) cases were classified according to the histologic criteria (modified) of Rappaport, to determine the extent of morphologic similarities of the tumors. In four families affected members had different tumor histologies that may be observed in an individual patient as the lymphoma progresses. In two families, the affected relatives had tumors of seemingly discordant histology. These tumors may nonetheless be etiologically related as indicated by the pattern of laboratory abnormalities, especially immunologic, in affected as well as unaffected members. The 20 cases had a reversal of the sex ratio (M/F) usually seen in NHL: 0.5 instead of 1.3. Other tumors observed in these families included primary hepatocellular carcinoma, pulmonary adenocarcinoma, Hodgkin disease, and acute lymphocytic leukemia - all of which have been associated with inborn or acquired immunodeficiency states.
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PMID:Familial non-Hodgkin lymphoma: histologic diversity and relation to other cancers. 27 64

Immunization of rabbits with rat leukemia DBLA-6 resulted in the production of antisera which upon absorption with hepatoma cells were specific for rat immature T lymphocytes. The antisera showed cytotoxicity against thymocytes and killed 75 approximately 90% of them, whereas the antisera had no cytotoxic effect on peripheral lymphocytes from the spleen, lymph node, and bone marrow of rats. The antisera also showed cytotoxicity against rat lymphatic leukemia and lymphoma cells of all lines tested but not against rat myelogenous leukemia and erythroleukemia cells. The cytotoxic activity of anti-DBLA-6 serum was completely absorbed with rat brain or thymocytes.
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PMID:Heterologous antiserum to a subpopulation of thymocytes and lymphomas in rats. 31 55


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