1
|
Abstract
Neoplasia is a heritably altered, relatively autonomous growth of tissue. Hepatocarcinogenesis, the pathogenesis of neoplasia in liver, as modeled in the rat exhibits three distinct, quantifiable stages: initiation, promotion, and progression. Simple mutations and/or epigenetic alterations may result in the irreversible stage of initiation. The stage of promotion results from selective enhancement of cell replication and selective inhibition of cellular apoptosis of initiated cells dependent on the genetic and/or epigenetic alterations of the latter. The irreversible stage of progression results from initial karyotypic alterations that evolve into greater degrees of genomic instability. The initial genomic alteration in the transition from promotion to progression may involve primarily epigenetic mechanisms driven by epigenetic and genetic alterations fixed during the stage of promotion.
Collapse
Affiliation(s)
- Henry C Pitot
- McArdle Laboratory for Cancer Research, Department of Oncology and Pathology, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
| |
Collapse
|
2
|
|
3
|
Harrap KR, Jackman AL, Newell DR, Taylor GA, Hughes LR, Calvert AH. Thymidylate synthase: a target for anticancer drug design. ADVANCES IN ENZYME REGULATION 1989; 29:161-79. [PMID: 2633608 DOI: 10.1016/0065-2571(89)90099-x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
N10-Propargyl-5,8-dideazafolic acid (CB3717) has proved to be an interesting recent addition to the spectrum of antifolate drugs. Its sole biochemical locus of action appears to be thymidylate synthase, an inhibitory effect which is potentiated by intracellular polyglutamation. The drug has shown a spectrum of clinical activity and toxicity which is unusual for an antimetabolite. It seems likely that the former is attributable to its inhibition of TS, whilst the latter relates to the drug's poor aqueous solubility at physiological pH. Seminal to the discovery of a new generation of more selective thymidylate synthase inhibitors has been the observation that the C2 desamino derivative (CB3804) retains the useful TS-inhibitory and cytotoxic properties of CB3717. It is some two orders of magnitude more water soluble than CB3717 at physiological pH and appears not to produce, in the mouse, the liver and kidney toxicities which have restricted the wider use of CB3717. Thus, in desamino CB3717, it has proved possible to separate the structural features determining antitumor activity from those which are responsible for its systemic toxicities. These encouraging results prompted systematic structure-activity studies of other C2-modified quinazolines, which revealed that the desirable properties of the desamino compound are not unique. Results with two other CB3717 analogues, the C2-methyl (CB3819) and C2-methoxy (CB3828), have been discussed in the present paper. All three CB3717 analogues exhibit TS-inhibitory activities which are broadly comparable to those of the parent drug. In continuous culture CB3828 is as cytotoxic as CB3717, while CB3804 and CB3819 are at least an order of magnitude more potent. As with the desamino derivative (CB3804), so CB3819 is substantially more water soluble than CB3717 and is apparently devoid of its major toxicities. However, the effects of CB3828 on whole cell TS inhibition, both in vitro and in vivo, are rapidly reversible upon removal of exogenous compound, while the inhibition is sustained in similar experiments with the other three compounds. It is likely that these effects relate to the extent to which the various derivatives are converted to polyglutamate species and retained intracellularly. With the exception of CB3828, all are good substrates for FPGS, and the polyglutamate derivatives of CB3717, CB3804 and CB3819 are better TS inhibitors than the corresponding monoglutamates. CB3804 and CB3819 are less toxic and are cleared from the plasma much more rapidly than CB3717, so that the rate and extent of their polyglutamation may be an essential prerequisite of pharmacological activity.(ABSTRACT TRUNCATED AT 400 WORDS)
Collapse
Affiliation(s)
- K R Harrap
- Drug Development Section, Institute of Cancer Research, Surrey, U.K
| | | | | | | | | | | |
Collapse
|
4
|
Takimoto CH, Tan YY, Cadman EC, Armstrong RD. Correlation between ribosomal RNA production and RNA-directed fluoropyrimidine cytotoxicity. Biochem Pharmacol 1987; 36:3243-8. [PMID: 2444230 DOI: 10.1016/0006-2952(87)90640-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The relationship between cytotoxicity and fluoropyrimidine effects on the production of mature cytoplasmic 28S and 18S ribosomal RNA was studied in S-180 cells for the fluoropyrimidines: 5-fluorouracil (FUra), 5-fluorouridine (FUrd), 5-fluorodeoxyuridine (FdUrd), and 5'-deoxy-5-fluorouridine (5'-dFUrd). After a 6-hr drug exposure, the total cytotoxicity in the absence of added thymidine (dThd) was determined by soft-agar cloning and resulted in LC90 (lethal concentration to 90% of cells) values of 0.6 microM FdUrd, 0.7 microM FUrd, 5.3 microM FUra and 93 microM 5'-dFUrd. The RNA-directed (dThd-nonreversible) cytotoxicity was assessed by cloning the cells in the presence of 10 microM dThd. This resulted in an altered order of potency and increased LC90 values to 5.5 microM FUrd, 20 microM FUra, 265 microM FdUrd and 870 microM 5'-dFUrd. The production of mature cytoplasmic rRNA was determined by measuring the amount of [3H]cytidine incorporated into the 28S and 18S rANA species following their separation by agarose gel electrophoresis, compared with the level of [3H]cytidine incorporated into the nuclear rRNA. When all four fluoropyrimidines were compared together, the degree of inhibition of cytoplasmic rRNA production was poorly predictive of the total cytotoxicity in the absence of dThd (correlation coefficient, r = 0.77). FdUrd, in particular, had a very minor effect on rRNA production even at very toxic drug concentrations. When toxicity was assessed in the presence of dThd, however, there was a strong and significant correlation between rRNA production and RNA-directed cytotoxicity (r = 0.95, P less than 0.001), for all the fluoropyrimidines tested, including FdUrd. Thus, when the inhibition of thymidylate formation was eliminated as a site of drug action and only RNA-directed cytotoxicity was assessed, the impaired production of cytoplasmic rRNA was strongly associated with cytotoxicity. These results demonstrate that the inhibition of mature cytoplasmic rRNA production may be an important common mechanism of RNA-directed cytotoxicity for all the fluoropyrimidines, and not limited to FUrd or FUra.
Collapse
Affiliation(s)
- C H Takimoto
- Cancer Research Institute, University of California, San Francisco 94143
| | | | | | | |
Collapse
|
5
|
Eliezri YD, Silvers DN, Horan DB. Role of preoperative topical 5-fluorouracil in preparation for Mohs micrographic surgery of extramammary Paget's disease. J Am Acad Dermatol 1987; 17:497-505. [PMID: 2821087 DOI: 10.1016/s0190-9622(87)70236-9] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The true extent of the skin affected in extramammary Paget's disease is frequently well beyond its clinical borders. A case of extramammary Paget's disease of the scrotum was treated with Mohs micrographic surgery. Prior to surgery, 5-fluorouracil was applied topically for 10 days. This resulted in a sharply delineated, erythematous patch of biopsy-proved extramammary Paget's disease well beyond the original clinical borders. This increased the visible area of disease by 60%. Mohs micrographic surgery detected microscopic extramammary Paget's disease approximately 1 cm beyond the erythematous borders. The location of disease farthest from the margins was in the direction toward which this erythema was most advanced when the application of 5-fluorouracil was discontinued. At the time of writing, 3.5 years after treatment, the patient was free of disease. Topical 5-fluorouracil may have a role as an adjunct to surgery by highlighting subclinical areas of extramammary Paget's disease. It may also be useful postoperatively to detect early disease recurrence.
Collapse
Affiliation(s)
- Y D Eliezri
- Department of Dermatology, Columbia Presbyterian Medical Center, New York, NY
| | | | | |
Collapse
|
6
|
Weckbecker G, Keppler DO. Substrate properties of 5-fluorouridine diphospho sugars detected in hepatoma cells. Biochem Pharmacol 1984; 33:2291-8. [PMID: 6466351 DOI: 10.1016/0006-2952(84)90669-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Nucleotide sugars derived from 5-fluorouridine were studied in cultured AS-30D hepatoma cells as well as in kinetic enzyme assays in vitro in comparison with the physiologic uridine diphospho sugars. Hepatoma cells converted 5-fluoro [14C]uridine to 5-fluorouridine diphospho (FUDP) glucose, FUDP-galactose, FUDP-N-acetylglucosamine, FUDP-N-acetylgalactosamine, and trace amounts of FUDP-glucuronate, as analyzed by different systems of high-performance liquid chromatography. 5-Fluoro[14C]uridine and [14C]uridine, at concentrations of 5 microM in the culture medium, were phosphorylated by the cells during 60 min to similar amounts of FUTP and UTP, respectively, while the synthesis of [14]FUDP-sugars was reduced to 14% as compared to that of [14C]UDP-sugars. FUDP-sugars, synthesized by chemical and enzymatic procedures, were assayed in vitro as substrates for enzymes of UDP-sugar metabolism. Km and V values in a range comparable to that of the respective UDP-sugars were determined for FUDP-sugars in the reactions catalyzed by UDP-glucose pyrophosphorylase, galactose-1-phosphate uridylyltransferase, UDP-glucose 4-epimerase, UDP-N-acetylglucosamine 2-epimerase, glycogen synthase, and UDP-glucose dehydrogenase. Our experiments in hepatoma cells and with enzymes in vitro have revealed additional reactions of FUDP-sugar metabolism demonstrating a metabolite pattern analogous to that of UDP-sugars. The amounts of FUDP-sugars formed relative to UDP-sugars in intact cells were smaller than suggested on the basis of their kinetic comparison in vitro.
Collapse
|
7
|
Eriksson G, Stenram U. The effect of 5-fluoroorotic acid on the early labelling of nucleotides and RNA in whole liver and of RNA in subnuclear fractions in rats given 3H-orotic acid. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1984; 165 Pt A:543-5. [PMID: 6202117 DOI: 10.1007/978-1-4684-4553-4_104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Male white rats were given either orotic acid or 5-fluoroorotic acid 60 min, and 3H-orotic acid 3 1/2 min before sacrifice. Liver nucleotides were analyzed by isotachophoresis. The (F)UTP pool increased to the same extent in both groups and showed the same specific labelling. The RNA synthesis, as measured by nmol of UTP entering RNA-UMP/g wet liver tissue was significantly lower in fluoroorotic acid treated rats. In the nucleolar fraction there was an increase in the RNA/DNA ratio, a decrease in the specific RNA labelling and an essentially unaltered specific labelling of RNA/microgram/DNA. The effect on the specific labelling of RNA/microgram DNA was the same in the nucleolar fraction and the nucleolar-free pellet, suggesting that the transcription of RNA in these two fractions proceeded in a similar way. There was a slight increase in the specific RNA labelling of the supernatant subnuclear fraction, containing low-molecular weight RNA. Incorporation into UDP-hexoses and UDP-N-acetylhexosamine was unchanged.
Collapse
|
8
|
Kizer DE, Clouse JA, Howell BA, Cox B, Ringer DP. Evidence that free polysomes are not the precursors of membrane-bound polysomes in rat liver. BIOCHIMICA ET BIOPHYSICA ACTA 1982; 697:353-62. [PMID: 7104363 DOI: 10.1016/0167-4781(82)90099-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
We tested, in rat liver, the postulate that free polysomes were precursors of membrane-bound polysomes. Three methods were used to isolate free and membrane-bound ribosomes from either post-nuclear or post-mitochondrial supernatants of rat liver. Isolation and quantitation of 28 S and 18 S rRNA allowed determination of the 40 S and 60 S subunit composition of free and membrane-bound ribosomal populations, while pulse labeling of 28 S and 18 S rRNA with [6-14C) orotic acid and inorganic (32P] phosphate allowed assessment of relative rates of subunit renewal. Throughout the extra-nuclear compartment, 40 S and 60 S subunits were present in essentially equal numbers, but, free ribosomes contained a stoichiometric excess of 40 S subunits, while membrane-bound ribosomes contained a complementary excess of 60 S subunits. Experiments with labeled precursors showed that throughout the extra-nuclear compartment, 40 S and 60 S subunits accumulated isotopes at essentially equal rates, however, free ribosomes accumulated isotopes faster than membrane-bound ribosomes. Among free ribosomes or polysomes, 40 S subunits accumulated isotopes faster than 60 S subunits, but, this relationship was not seen among membrane-bound ribosomes. Here, 40 S subunits accumulated isotope more slowly than 60 S subunits. This distribution of labeled precursors does not support the postulate that free polysomes are precursors of membrane-bound polysomes, but, these data suggest that membrane-bound polysomes could be precursors of free polysomes.
Collapse
|
9
|
Ardalan B, Glazer RI, Kensler TW, Jayaram HN, Van Pham T, Macdonald JS, Cooney DA. Synergistic effect of 5-fluorouracil and N-(phosphonacetyl)-L-aspartate on cell growth and ribonucleic acid synthesis in human mammary carcinoma. Biochem Pharmacol 1981; 30:2045-9. [PMID: 7295324 DOI: 10.1016/0006-2952(81)90221-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
|
10
|
Hadjiolova KV, Naydenova ZG, Hadjiolov AA. Inhibition of ribosomal RNA maturation in Friend erythroleukemia cells by 5-fluorouridine and toyocamycin. Biochem Pharmacol 1981; 30:1861-3. [PMID: 6944069 DOI: 10.1016/0006-2952(81)90026-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
|
11
|
Ouellette AJ, Silverberg MB, Malt RA. Association of poly(adenylate)-deficient messenger ribonucleic acid with membranes in mouse kidney. Biochemistry 1981; 20:3561-7. [PMID: 6114742 DOI: 10.1021/bi00515a040] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
To describe further the metabolism of messenger ribonucleic acid (mRNA) in mouse kidney, we examined newly synthesized mRNA deficient in poly(adenylate) [poly(A)]. Approximately 50% of renal polysomal mRNA that labeled selectively in the presence of the pyrimidine analogue 5-fluoroorotic acid lacks or is deficient in poly(A) as defined by its ability to bind to poly(A) affinity columns. Nearly one-half of this poly(A)-deficient mRNA is associated uniquely with a cellular membrane fraction detected by sedimentation of renal cytoplasm in sucrose density gradients containing EDTA and nonionic detergents. Poly(A+) mRNA and poly(A)-deficient mRNA [poly(A-) mRNA] have similar modal sedimentation coefficients (20-22 S) and similar cytoplasmic distribution. Although 95% of newly synthesized poly(A+) mRNA is released in 10 mM EDTA as 20-90 S ribonucleoproteins from polysomes greater than 80 S, only 55% of poly(A)-deficient mRNA is released under the same conditions. Poly(A)-deficient mRNA recovered from greater than 80 S ribonucleoproteins resistant to EDTA treatment lacks ribosomal RNA, is similar in size to poly(A+) mRNA, and is associated with membranous structures, since 70% of poly(A)-deficient mRNA in EDTA-resistant ribonucleoproteins is released into the 20-80 S region by solubilizing membranes with 1% Triton X-100. These membrane-associated renal poly(A-) mRNAs could have unique coding or regulatory functions.
Collapse
|
12
|
Holstege A, Anukarahanonta T, Yamamoto M, Koch HK, Kattermann R, Lesch R, Keppler D. Preventive effects of 5-fluorouridine and uridine on d-galactosamine-induced liver injury. Exp Mol Pathol 1981; 34:170-82. [PMID: 6162676 DOI: 10.1016/0014-4800(81)90073-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
|
13
|
Golovinsky E, Spassova M. Analogs of pyrimidine and purine mononucleotide precursors as metabolic inhibitors. Pharmacol Ther 1981; 13:385-420. [PMID: 7025038 DOI: 10.1016/0163-7258(81)90022-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
|
14
|
Purification by benzoylated cellulose chromatography of translatable messenger ribonucleic acid lacking polyadenylate. J Biol Chem 1980. [DOI: 10.1016/s0021-9258(19)85800-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|
15
|
|
16
|
Cardelli J, Long BH, Pitot HC. An examination of rat liver smooth endoplasmic reticulum membranes for the presence of associated messenger RNA. Arch Biochem Biophys 1978; 191:632-7. [PMID: 742894 DOI: 10.1016/0003-9861(78)90401-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
17
|
Lutz RW, Shires TK. Polysomal changes in rats treated with lethal doses of carbon tetrachloride. Toxicol Appl Pharmacol 1978; 45:653-63. [PMID: 725921 DOI: 10.1016/0041-008x(78)90159-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
18
|
Veselý J, Čihák A. 5-Azacytidine: Mechanism of action and biological effects in mammalian cells. ACTA ACUST UNITED AC 1978. [DOI: 10.1016/0362-5478(78)90016-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
19
|
Hadjiolov AA, Nikolaev N. Maturation of ribosomal ribonucleic acids and the biogenesis of ribosomes. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 1978; 31:95-144. [PMID: 790469 DOI: 10.1016/0079-6107(78)90006-8] [Citation(s) in RCA: 115] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
20
|
George CB, Cory JG. Metabolism of the dialdehyde derivative of inosine (NSC-118994): transport, distribution and incorporation into RNA of Ehrlich ascites tumor cells. Biochem Pharmacol 1977; 26:1197-204. [PMID: 880267 DOI: 10.1016/0006-2952(77)90106-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
21
|
Alam SN, Shires TK. The labeling of polysomes and rough microsomal membranes by 5-fluoroorotic acid. Biochem Biophys Res Commun 1977; 74:1441-9. [PMID: 843370 DOI: 10.1016/0006-291x(77)90603-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
22
|
|
23
|
Yatvin MB, Abdel-Halim MN. Liver RNA metabolism in adrenalectomized and intact whole-body irradiated and 5-fluoroorotic acid treated rats. Int J Radiat Oncol Biol Phys 1976; 1:945-50. [PMID: 977425 DOI: 10.1016/0360-3016(76)90120-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
24
|
Abdel-Halim MN, Yatvin MB. Electrophoretic analysis of liver rRNA maturation in irradiated and 5-fluoroorotic acid treated rats. Int J Radiat Oncol Biol Phys 1976; 1:951-6. [PMID: 977426 DOI: 10.1016/0360-3016(76)90121-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
25
|
Sidebottom E, Deák II. The function of the nucleolus in the expression of genetic information: studies with hybrid animal cells. INTERNATIONAL REVIEW OF CYTOLOGY 1976; 44:29-53. [PMID: 177380 DOI: 10.1016/s0074-7696(08)61646-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
26
|
Herzog J, Farber JL. Fibrillar nucleolar remnants do not contain macromolecular precursors of ribosomal RNA. Demonstration by the effects of d-galactosamine. Exp Cell Res 1975; 93:502-5. [PMID: 50951 DOI: 10.1016/0014-4827(75)90482-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
27
|
Pestana A, Pitot HC. Acetylation of ribosome-associated proteins in vitro by an acetyltransferanse bound to rat liver ribosomes. Biochemistry 1975; 14:1397-403. [PMID: 235951 DOI: 10.1021/bi00678a009] [Citation(s) in RCA: 37] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Incubation of rat liver ribosomes with [1-14-C]acetyl-coenzyme A results in the incorporation of [14-C]acetyl into a material insoluble in cold trichloroacetic acid. The acetyltransferase involved in the self-acetylation of ribosomes can be released by high salt washing of the ribosomes; the activity of the solubilized enzyme can be assayed using histones as acetyl acceptors. Electrophoretic analysis of acetylated risosomes or ribosomal proteins indicated that the acetyl radicals are associated with a group of relatively basic proteins, having molecular weights ranging from 10,000 to 45,000. Chromatographic analysis of the enzymatic hydrolsates of proteins extracted from acetylated ribosomes indicates that acetylation is mainly or exclusively NH2 terminal. Almost 80% of the acetyl proteins are released from the ribosomes by high salt treatment. Most of the acetyl radicals not solubilized by the high salt treatment were found in the 60S subunit, associated with a protein(s) having an apparent molecular weight of 43,000. This acetyl protein(s) was released from the 60S subunit by EDTA treatment and was found in a ribonucleoprotein complex having a bouyant density of 1.56.
Collapse
|
28
|
|
29
|
Weiss JW, Pitot HC. Effects of 5-azacytidine on nucleolar RNA and the preribosomal particles in Novikoff hepatoma cells. Biochemistry 1975; 14:316-26. [PMID: 47243 DOI: 10.1021/bi00673a018] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Examination of nucleolar RNA from cultured Novikoff hepatoma cells treated for 3 hr with 5 x 10-4 M 5-azacytidine shows that significant amounts of analog-substituted 45S RNA are processed to the 32S RNA species, but 28S RNA formation is completely inhibited. Under these conditions of analog treatment 37% of the cytidine residues in the 45S RNA is replaced by 5-azacytidine. During coelectrophoresis of nucleolar RNA from 5-azacytidine-treated and control cells, the analog-substituted 45S RNA and 32S RNA display reduced mobilities compared to the control 45S RNA and 32S RNA. Coelectrophoresis of analog-substituted and control RNA after formaldehyde denaturation shows no differences in electrophoretic mobility between the two RNA samples, suggesting that 5-azacytidine incorporation may alter the secondary structure of the 45S RNA and the 32S RNA. 5-Azacytidine at 5 x 10-4 M severely inhibits protein synthesis in Novikoff cells by 3 hr. After this length of treatment, however, CsCl buoyant density analysis reveals no difference in density of either the 80S or 55S preribosomal ribonucleoprotein particles when compared to normal particles. Also 5-azacytidine treatment does not appear to cause major changes in the polyacrylamide gel electrophoresis patterns of the proteins in the 80S and 55S preribosomal particles. These results together with previous findings suggest that 5-azacytidine's inhibition of rRNA processing is possibly related to its alteration of the structure of the ribosomal precursor RNAs and is not a consequence of a general inhibition of ribosomal protein formation.
Collapse
|
30
|
Weiss JW, Pitot HC. Alteration of ribosomal precursor RNA in Novikoff hepatoma cells by 5-azacytidine. Studies on methylation of 45S and 32S RNA. Arch Biochem Biophys 1974; 165:588-96. [PMID: 4140709 DOI: 10.1016/0003-9861(74)90286-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
31
|
Hahn GA, Mandel HG. The roles of various biochemical effects produced by 5-fluorouracil in early growth inhibition of Bacillus cereus. Biochem Pharmacol 1974; 23:2689-95. [PMID: 4214335 DOI: 10.1016/0006-2952(74)90039-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
32
|
Mohrenweiser HW, Pitot HC. Studies on the mechanism of 5-fluoroorotic acid inhibition of serine dehydratase induction. Arch Biochem Biophys 1974; 164:663-8. [PMID: 4142575 DOI: 10.1016/0003-9861(74)90078-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
33
|
Hadjiolov A, Hadjiolova K, Nikolov R, Emanuilov I. Evidence that the synthesis and nucleo-cytoplasmic transfer of liver messenger-like ribonucleic acid is independent of ribosomal ribonucleic acid maturation. ACTA ACUST UNITED AC 1974. [DOI: 10.1016/0020-711x(74)90130-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
34
|
Cory JG, Mansell MM, George CB, Wilkinson DS. Inhibition of nucleic acid synthesis in Ehrlich tumor cells by periodate-oxidized adenosine and adenylic acid. Arch Biochem Biophys 1974; 160:495-503. [PMID: 4364771 DOI: 10.1016/0003-9861(74)90426-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
|
35
|
Weiss JW, Pitot HC. Inhibition of ribosomal ribonucleic acid maturation by 5-azacytidine and 8-azaguanine in Novikoff hepatoma cells. Arch Biochem Biophys 1974; 160:119-29. [PMID: 4133377 DOI: 10.1016/s0003-9861(74)80016-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
36
|
Hadjiolova KV, Golovinsky EV, Hadjiolov AA. The site of action of 5-fluoroorotic acid on the maturation of mouse liver ribonucleic acids. BIOCHIMICA ET BIOPHYSICA ACTA 1973; 319:373-82. [PMID: 4747084 DOI: 10.1016/0005-2787(73)90177-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
|
37
|
Cihak A, Lamar C, Pitot HC. Studies on the mechanism of the stimulation of tyrosine aminotransferase activity in vivo by pyrimidine analogs: the role of enzyme synthesis and degradation. Arch Biochem Biophys 1973; 156:176-87. [PMID: 4125885 DOI: 10.1016/0003-9861(73)90355-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
38
|
Cihák A, Garret C, Pitot HC. Labeling of cytoplasmic liver RNA by (6- 14 C)orotic and 5-fluoro(2- 14 C)orotic acids. Effect of several inhibitors. EUROPEAN JOURNAL OF BIOCHEMISTRY 1973; 34:68-76. [PMID: 4121801 DOI: 10.1111/j.1432-1033.1973.tb02729.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
39
|
Mohrenweiser HW, Emery RS. Hormonal control of precursor pools, ribonucleic acid synthesis, and cellular morphology in mammary tissue pieces during lactogenesis. J Dairy Sci 1973; 56:436-45. [PMID: 4704641 DOI: 10.3168/jds.s0022-0302(73)85197-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
|
40
|
|
41
|
Garrett CT, Wilkinson DS, Tweedle JW, Pitot HC. Effect of 5-fluoroorotic acid administration of the 32 P base composition, DNA-RNA hybridization properties, and labeling of polyadenylate-rich RNA in the cytoplasm of rat liver cells. Arch Biochem Biophys 1973; 155:342-54. [PMID: 4705430 DOI: 10.1016/0003-9861(73)90123-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
|
42
|
Wilkinson DS, Pitot HC. Inhibition of Ribosomal Ribonucleic Acid Maturation in Novikoff Hepatoma Cells by 5-Fluorouracil and 5-Fluorouridine. J Biol Chem 1973. [DOI: 10.1016/s0021-9258(19)44445-1] [Citation(s) in RCA: 75] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|
43
|
Cihák A, Broucek J. Dual effect of 5-azacytidine on the synthesis of liver ribonucleic acids. Lack of the relationship between metabolic transformation of orotic acid in vitro and its incorporation in vivo. Biochem Pharmacol 1972; 21:2497-507. [PMID: 4119046 DOI: 10.1016/0006-2952(72)90421-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
|