scholarly journals INHIBITING EFFECT OF THE NEW CYTOTOXIC ANTIBIOTIC DAUNOMYCIN ON NUCLEIC ACIDS AND MITOTIC ACTIVITY OF HELA CELLS

1965 ◽  
Vol 27 (3) ◽  
pp. 545-550 ◽  
Author(s):  
A. Di Marco ◽  
R. Silvestrini ◽  
S. Di Marco ◽  
T. Dasdia
Keyword(s):  
Mitotic Activity ◽  
Rna Synthesis ◽  
Thymidine Incorporation ◽  
Acid Synthesis ◽  
Acetyl Derivative ◽  
Total Inhibition ◽  
Nuclear Rna ◽  
Nucleolar Rna ◽  
Higher Doses

The effect has been studied of Actinomycin D, Daunomycin (Da.), and Da. N acetyl derivative on mitotic activity and on the nucleic acid synthesis of in vitro HeLa cell cultures. The experiments were carried out by means of the radioautographic technique using stripping films. The relative uptake of thymidine-H3 and uridine-H3 was determined by means of the reduced silver grain count present in the nuclei of controls and treated cells. The mitotic activity and thymidine incorporation were noticeably reduced by Daunomycin and Actinomycin, whereas both processes appeared less affected by Da. N acetyl derivative. As regards nuclear RNA synthesis, all three antibiotics at low doses chiefly inhibit nucleolar RNA synthesis. On the other hand, whilst Actinomycin at higher doses causes an almost total inhibition of the synthesis of the whole nuclear RNA, in Daunomycin- and Da. N acetyl derivative-treated cells extranucleolar RNA synthesis is less susceptible to inhibition.

scholarly journals NUCLEOLAR AND NUCLEAR RNA SYNTHESIS DURING THE CELL LIFE CYCLE IN MONKEY AND PIG KIDNEY CELLS IN VITRO

1967 ◽  
Vol 33 (2) ◽  
pp. 273-279 ◽  
Author(s):  
Jane L. Showacre ◽  
W. G. Cooper ◽  
D. M. Prescott
Keyword(s):  
Life Cycle ◽  
Rna Synthesis ◽  
Kidney Cells ◽  
Pig Kidney ◽  
Rna Labeling ◽  
Cell Life ◽  
Nuclear Rna ◽  
Nucleolar Rna ◽  
Pig Kidney Cells

The incorporation of 5-3H-uridine and 5-3H-cytidine into nucleolar and nonnucleolar RNA in the nucleus of monkey and pig kidney cells was measured in vitro during the cell life cycle. Time-lapse cinematographic records were made of cells during asynchronous exponential proliferation, in order to identify the temporal position of individual cells in relation to the preceding mitosis. Immediately following cinematography, cells were labeled with uridine-3H and cytidine-3H for a short period, fixed, and analyzed by radioautography. Since the data permit correlation of the rate of RNA labeling with the position of a cell within the cycle, curves could be constructed describing the rate of RNA synthesis over the average cell cycle. RNA synthesis was absent in early telophase, and rose very abruptly in rate in late telophase and in very early G1 in both the nucleus and the reconstituting nucleolus. Thereafter, through the G1 and S periods the rate of nuclear RNA synthesis rose gradually. When we used a 10-min pulse, there was no detectable change in the rate for nucleolar RNA labeling in monkey kidney cells during G1 or S. When we used a 30-min labeling time, the rate of nucleolar RNA labeling rose gradually in pig kidney cells. With increasing time after mitosis, the data became more variable, which may, in part, be related to the variation in generation times for individual cells.

Effect of Daunorubicin and Adriamycin on Nucleic ACID Synthesis of Serum Stimulated Mouse Embryo Fibroblasts

1977 ◽  
Vol 63 (1) ◽  
pp. 31-41 ◽  
Author(s):  
Rosanna Supino ◽  
Anna M. Casazza ◽  
Aurelio Di Marco
Keyword(s):  
Dna Synthesis ◽  
Mouse Embryo ◽  
Rna Synthesis ◽  
Calf Serum ◽  
Acid Synthesis ◽  
Anthracycline Antibiotics ◽  
Simple Method ◽  
Mouse Embryo Fibroblasts ◽  
Embryo Fibroblasts

This paper reports the effects of daunorubicin and adriamycin on DNA and RNA synthesis of in vitro cultured mouse embryo fibroblasts (MEF) stimulated by fetal calf serum (FCS). The addition of FCS to quiescent MEF cultures brings about a wave of RNA synthesis, followed by DNA synthesis which starts between 8 and 12 h after change of medium and proceed for up to 24 h. These cells are therefore partially synchronized. The level of DNA synthesis depends on the amount of FCS added. Daunorubicin and adriamycin are almost equally effective in inhibiting DNA synthesis, as well as cell proliferation, which takes place later. Adriamycin is more active than daunorubicin on RNA synthesis. In cultures treated for an 8 h period starting at different times after FCS addition, the highest DNA synthesis inhibition is achieved by treatment during the first 8 h, when DNA synthesis has not yet started. The cellular uptake of daunorubicin is constantly higher than that of adriamycin, in any experimental condition tested. The results show that FCS-stimulated MEF can provide a simple method for studying the effects of anthracycline antibiotics on partially synchronized cells.

In Vitro Biological Activity of Adriamycin

1970 ◽  
Vol 56 (3) ◽  
pp. 137-148 ◽  
Author(s):  
Rosella Silvestrini ◽  
Carmela Gambarucci ◽  
Teresa Dasdia
Keyword(s):  
Biological Activity ◽  
Cellular Proliferation ◽  
Therapeutic Index ◽  
Dna And Rna ◽  
Total Inhibition ◽  
A Cell ◽  
Nuclear Structures ◽  
Higher Doses

Adriamycin is an antibiotic, isolated from cultures of a mutant of Streptomyces peucetius, var. caesius, with a chemical structure very similar to daunomycin but with a higher therapeutic index in experimental tumors. The biological activity of this antibiotic has been studied in vitro on the HeLa cell strain. Adriamycin quickly penetrates into the cells and fixes to the nuclear structures with a marked localization at the level of the perinucleolar chromatin. It causes a marked and immediate disturbance of the mitotic process, viz. pre-prophasic inhibition at the low doses and mitotic block at the higher doses. Even the synthesis of DNA and RNA, evaluated autoradiographically as incorporation of 3H-thymidine and 3H-uridine, appear markedly inhibited. The viability of the cells, tested both as regards capacity to give rise to colonies and as regards proliferative activity of a cell population, was seriously reduced, in a degree proportional to the period of treatment and to the concentration of the antibiotic, until total inhibition. In comparison with daunomycin, adriamycin exerts an immediate antimitotic and anti-metabolic effect which, at equivalent doses, is slightly lower than that of daunomycin. The long-term antiproliferative activity on cellular proliferation is however, identical for the two antibiotics.

Ribonucleic acid synthesis inPlasmodium knowlesimaintained bothin vivoandin vitro

Parasitology ◽  
1975 ◽  
Vol 71 (2) ◽  
pp. 199-209 ◽  
Author(s):  
P. I. Trigg ◽  
P. G. Shakespeare ◽  
Susan J. Burt ◽  
Sally I. Kyd
Keyword(s):  
Ribosomal Rna ◽  
Rna Synthesis ◽  
Nuclear Division ◽  
Plasmodium Knowlesi ◽  
Acid Synthesis ◽  
Agarose Gel Electrophoresis ◽  
Trophozoite Stage ◽  
Late Trophozoite

RNA extracted from purified parasites ofPlasmodium knowlesiwas fractionated using agarose gel electrophoresis. Preparations from parasites grown bothin vivoandin vitrocontained species of RNA with sedimentation coefficients of 4·0S, 5·0S, 16·6S, 24·2S, 31·4S, 38·0S and 48·3S. There was less RNA present in parasites grownin vitrothan the equivalent stage parasites grownin vivobut the proportional amounts of the various species of RNA was similar in both cases. It is suggested that the 24·2S and 16·6S species of RNA are ribosomal and that the high molecular weight 31·4S, 38·0S and 48·0S species are ribosomal precursors. Ribosomal RNA synthesis occurs throughout the cell cycle during growth from the ring to the schizont stage; maximum incorporation of [H3]-adenosine occurs at the late trophozoite stage before nuclear division.

scholarly journals Mechanism of action of purpuromycin

1992 ◽  
Vol 284 (1) ◽  
pp. 47-52 ◽  
Author(s):  
P Landini ◽  
E Corti ◽  
B P Goldstein ◽  
M Denaro
Keyword(s):  
Protein Synthesis ◽  
Rna Synthesis ◽  
Intact Cell ◽  
Acid Synthesis ◽  
Free System ◽  
Dna And Rna ◽  
Dna And Rna Synthesis ◽  
Dependent Protein ◽  
Elongation Step

Purpuromycin, an antibiotic active against both fungi and bacteria, shows different modes of action against these two kinds of micro-organisms; in Candida albicans it inhibits RNA synthesis, whereas in Bacillus subtilis protein synthesis is primarily affected, with DNA and RNA synthesis blocked at higher concentrations of the drug. In bacterial cell-free protein-synthesis systems, purpuromycin did not inhibit synthesis from endogenous mRNA (elongation of peptides initiated within the intact cell) but inhibited MS2-phase RNA-dependent protein synthesis (which requires initiation) by 50% at 0.1 mg/l. Poly(U)-directed polyphenylalanine synthesis was 50% inhibited by 20 mg of purpuromycin/l when added to a complete system; however, when purpuromycin was preincubated with ribosomes dissociated into 30 S and 50 S subunits, the concentration for 50% inhibition fell to 0.1 mg/l. By contrast, in a C. albicans cell-free system poly(U)-directed polyphenylalanine synthesis was partially inhibited only at 200 mg/l. Purpuromycin also inhibited polynucleotide synthesis in vitro in reactions using Escherichia coli or wheat-germ RNA polymerases or E. coli DNA polymerase I. We suggest that in bacteria the primary target of purpuromycin is on ribosomes and that its action precedes the elongation step of protein synthesis. The effect on nucleic acid synthesis in both fungi and bacteria may be due to interaction of purpuromycin with DNA.

Differential Effects of Growth Hormone and Hydrocortisone on Nuclear RNA Synthesis in Rat Liver

1971 ◽  
Vol 49 (7) ◽  
pp. 853-862 ◽  
Author(s):  
Peter M. K. Ip ◽  
Maurice Brossard
Keyword(s):  
Growth Hormone ◽  
Rat Liver ◽  
Rna Synthesis ◽  
Present Report ◽  
Liver Nucleus ◽  
Double Labeling ◽  
Nuclear Rna Synthesis ◽  
Nuclear Rna ◽  
Liver Nuclei ◽  
Nucleolar Rna

RNA has been isolated and fractionated from rat liver nuclei by a sequence of salt extractions into four subfractions: namely nucleoplasmic, deoxyribonucleoprotein-associated, ribonucleoprotein-associated, and nucleolar fractions.Study of 14C-methyl-methionine labeling indicates that the nucleolar RNA fraction isolated by the present procedure is, in fact, of nucleolar origin while the other three fractions are essentially of extranucleolar origin.The effects of growth hormone and hydrocortisone on the nuclear RNA synthesis have been further studied using the present isolation and double-labeling techniques. Both hormones cause an increase in the incorporation of labeled orotic acid into all types of RNA in all four nuclear subfractions. However, the stimulatory effect of growth hormone is found mainly in the 18–28 S and 45–60 S regions of the nucleolar fraction and in regions of the entire gradient of the nucleoplasmic fraction, whereas the stimulatory effect of hydrocortisone is localized mainly in the 10–28 S regions of the nucleolar fraction and in the 4 S and 10–18 S regions of the ribonucleoprotein fraction.The present report suggests that there are qualitative as well as quantitative differences in the action of growth hormone and hydrocortisone on the synthesis of RNA in liver nucleus. The mode of action of the two hormones is discussed.

Uptake of [3H]Uridine into Precursor Pools and RNA in Osteogenic Cells

1967 ◽  
Vol 2 (1) ◽  
pp. 39-56
Author(s):  
MAUREEN OWEN
Keyword(s):  
Protein Synthesis ◽  
Mammalian Cells ◽  
Rna Synthesis ◽  
Degradation Products ◽  
Cell Types ◽  
Water Soluble ◽  
Radioactive Label ◽  
Cytoplasmic Rna ◽  
Nuclear Rna

Young rabbits were given a single intraperitoneal injection of [3H]uridine. Using the technique of water-soluble autoradiography a study was made of the uptake of the radioactive label into soluble precursors and RNA in cells on an actively growing bone surface. Labelling of the soluble intracellular pools was immediate, but incorporation of label from these pools into RNA was not completed until 24 h after injection. At this time all the label in the sections was in RNA but this represented only 30% of the total label initially in the soluble pools. This means that 70% of the label is lost from the cell in the first 24 h either as degradation products of RNA synthesis or by other as yet unknown mechanisms. The pattern of labelling of the RNA was similar to that previously found for other mammalian cells in vivo or in vitro. There was a rapid uptake of label into nuclear RNA which reached a maximum by 2 h after injection and a slower uptake into cytoplasmic RNA which reached a maximum by 24 h after injection. There was a slow loss of label from the cells after 24 h indicating a half-life of about 8 days for this relatively stable RNA. A comparison was made of RNA synthesis in the proliferating preosteoblasts and the highly differentiated non-dividing osteoblasts. Labelling of the nuclear RNA for the two cell types was identical. The rate of labelling of the cytoplasmic RNA was similar for the two cell types but the maximum level of labelling in the cytoplasm of the osteoblasts was 2 to 3 times that in the preosteoblasts. This could be correlated with the more active protein synthesis by the osteoblasts. There was a slow loss of labelled RNA by the osteoblasts and preosteoblasts and a rapid loss by the osteocytes after the cells had been incorporated within the bone. It was suggested that this loss paralleled the decline in the rate of protein synthesis by the cells as their environment changed.

scholarly journals Ribonucleic acid synthesis in the renal cortex at the initiation of compensatory growth

1976 ◽  
Vol 158 (2) ◽  
pp. 457-470 ◽  
Author(s):  
P Cortes ◽  
N W Levin ◽  
P R Martin
Keyword(s):  
Rna Synthesis ◽  
Compensatory Growth ◽  
Renal Cortex ◽  
Acid Synthesis ◽  
Sham Operation ◽  
Precursor Pool ◽  
Cortex Slices ◽  
Endogenous Precursor

The mechanisms responsible for the increase in RNA per cell during the first 48h of renal compensatory growth were studied in the renal cortex. Unilaterally nephrectomized, sham-operated or non-operated rats were used. Incorporation into RNA of labelled precursors was studied in vivo and in vitro. Sham-operation produced significant changes in precursor incorporation, absolute amounts of UTP and RNA, and the rate of RNA synthesis. At 6h after surgery, the amount of RNA decreased in sham-operated controls, whereas that in growing cortex remained unchanged. Incorporation into RNA in vivo was greater in the growing cortex, although the rate of RNA synthesis was not increased. At 24h, precursor incorporation into RNA and UTP and RNA synthesis were all increased in the growing cortex. In contrast with results obtained in vivo, slices of growing cortex incorporated less labelled precursor into RNA than did cortex slices from sham-operated controls, from 3 to 48h. Maximal differences were found from 6 to 24h. An attempt was made to equalize endogenous precursor pool sizes by increasing the concentration of unlabelled uridine in the media; incorporation differences were narrowed significantly. Serum from nephrectomized animals did not increase precursor incorporation into RNA in vitro. An increase in RNA synthesis is an important factor in RNA accretion in the renal cortex beyond 12h of compensatory growth. This is accompanied by increased UTP content and preceded by expansion of other pools. The amount of labelled precursor incorporated into RNA is greatly influenced by its delivery rate to the growing kidney in vivo and by intracellular dilution of expanded precursor pools in vitro.

The influence of seizures on nuclear RNA synthesis in vitro from el mouse cerebral corticles

1985 ◽  
Vol 1 ◽  
pp. S17
Author(s):  
Sakae Yamagami ◽  
Hiroshi Onishi ◽  
Kyosuke Ohno ◽  
Koichi Mori ◽  
Yukio Kawakita
Keyword(s):  
Rna Synthesis ◽  
El Mouse ◽  
Nuclear Rna Synthesis ◽  
Nuclear Rna
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