Cytoplasmic DNA of hepatoma tumor cells studied by3H-actinomycin D binding

1975 ◽  
Vol 31 (3) ◽  
pp. 360-361 ◽  
Author(s):  
Joanne Aczel ◽  
Hildegard E. Enesco
1986 ◽  
Vol 39 (2) ◽  
pp. 205-221 ◽  
Author(s):  
Francesco Colotta ◽  
Nadia Polentarutti ◽  
Laura Bersani ◽  
Guido Poll ◽  
Alberto Mantovani

1974 ◽  
Vol 52 (3) ◽  
pp. 263-267 ◽  
Author(s):  
Floyd F. Snyder ◽  
J. Frank Henderson

Actinomycin D treatment of Ehrlich ascites tumor cells in vitro causes slight to moderate inhibition of purine ribonucleotide synthesis de novo and from purine bases, and strong inhibition of inosinate dehydrogenase activity. These effects have the same dose–response relationship as inhibition of RNA synthesis by this drug. Daunomycin has similar effects on purine metabolism at a concentration that substantially inhibits nucleic acid synthesis. Actinomycin D treatment leads to elevated intracellular concentrations of ATP and GTP, and the effects of this drug on purine metabolism are believed to be mediated by these purine ribonucleoside triphosphates.


1964 ◽  
Vol 42 (6) ◽  
pp. 859-870 ◽  
Author(s):  
R. A. Cook ◽  
J. P. Bouchard ◽  
M. J. Fraser

Preliminary observations have been made on the biosynthesis of amino acid acceptor RNA in the mouse Ehrlich ascites carcinoma. Measurements have been made of the incorporation of radioactivity from either14C-CH3-methionine or uridine-2-14C into the RNA of nuclear and cytoplasmic fractions which precipitate at pH 5.0 from 105,000 × g supernatants of broken nuclei preparations and of cell homogenates ("soluble" RNA or sRNA). With either labelled precursor higher specific activities were found in the nuclear than in the cytoplasmic sRNA fractions. Whereas actinomycin D and DNase inhibited the incorporation of radioactivity from uridine-2-14C into nuclear sRNA, these agents stimulated significantly the incorporation of radioactivity from14C-CH3-methionine. The glycine acceptor capacity of nuclear sRNA was found to be greater than that of cytoplasmic sRNA. The base ratios of the amino acid acceptor RNA fractions derived from nuclear sRNA and from cytoplasmic sRNA by chromatography on methylated albumin columns were very similar. The results are consistent with the hypothesis that the amino acid acceptor RNA is made on a DNA-template in the nucleus of the tumor cells, is subsequently released from the template, methylated, and then transferred to the cytoplasm.


1985 ◽  
Vol 11 (5-6) ◽  
pp. 351-355 ◽  
Author(s):  
Laura Bersani ◽  
Francesco Colotta ◽  
Pietro Ghezzi ◽  
Alberto Mantovani
Keyword(s):  

1965 ◽  
Vol 24 (2) ◽  
pp. 267-276 ◽  
Author(s):  
Effat Badr Mourad

Sterile root cultures from Nicotiana tabacum were grown with H3-thymidine added to the medium for various intervals. Incorporation of the labeled nucleoside into nuclear DNA occurred in a fraction of the nuclei which increased with time. In addition, the cytoplasm of all cells incorporated enough tritium to be readily detected by autoradiography. The tritium was not removed by hydrolysis in 1 N HCl at 60°C for 10 minutes, but was removed by digestion in a DNase solution which also removed nuclear DNA. The amount of tritium in the cytoplasm increased during the first 2 hours, but did not appear to increase significantly during the following 5 hours. If the roots were transferred to unlabeled medium after 2 hours, the label was diluted faster than expected by growth without turnover of the labeled component. If FUdR was added to the unlabeled medium, the depletion occurred faster during the first 6 hours, but later appeared to level off so that at 10 hours these cultures did not differ from those incubated without FUdR. However, the addition of an excess of unlabeled carrier had no effect on the rate of depletion of the cytoplasmic label. Actinomycin D, which inhibited the incorporation of H3-cytidine into RNA in the root tips, had no effect on the incorporation of H3-thymidine into the cytoplasmic component. However, Mitomycin C or a high concentration of deoxyadenosine inhibited the incorporation of H3-thymidine into the cytoplasmic component as well as into the nuclear DNA. It is concluded that H3-thymidine is incorporated into a cytoplasmic fraction which has the characteristics of DNA, with a measurable rate of turnover. This fraction is synthesized regardless of whether or not the nucleus is synthesizing DNA. Although the function of cytoplasmic fraction is not yet known, it does not appear to be that of supplying precursors for the synthesis of the nuclear DNA.


1972 ◽  
Vol 50 (3) ◽  
pp. 244-252 ◽  
Author(s):  
Richard G. von Tigerstrom

Ehrlich ascites cells were treated with actinomycin D before transplantation. These cells, collected after 7 days, show increased alkaline RNase II, acid RNase II, and phosphodiesterase II activities and low RNase inhibitor activity as compared to untreated tumor cells collected 7 days after transplantation. RNase I, phosphodiesterase I, and acid phosphatase activities were unchanged. Smaller increases in the same enzyme activities, but no change in RNase inhibitor activity, were observed when untreated cells collected after 4 days were compared to untreated cells collected after 7 days of growth. Ehrlich ascites cells collected after 4 days synthesized protein and RNA at a slightly faster rate than those collected after 7 days. Actinomycin D treated cells synthesized protein at a rate identical to that of the control cells; net synthesis of RNA, however, was significantly reduced. One possible reason for this may be the higher RNase and phosphodiesterase activities in actinomycin D treated cells.


2019 ◽  
Author(s):  
Koji Nishio ◽  
Shanlou Qiao ◽  
Kung Sang Chang

AbstractBackgroundRNA binding motif (RBM) proteins, RBM10v1, RBM10v2 and RBM5 share a high degree of the conserved domains. So far, the drug-sensitivities of the RBMs in tumor cells have not been fully examined.ObjectiveThe expression profiles of RBM10 and RBM5 in several virus-transformed tumor cells, and the effect of the most established antitumor agents, actinomycin D and doxorubicin, were investigated.Methods and ResultsDoxorubicin and actinomycin D differentially reduced RBM10 and RBM5 protein, respectively in both of HeLa and COS-7 cells. RBM10 protein was highly sensitive to doxorubicin in HeLa, COS-7 and A549 cells. In silico analysis revealed the several sumoylation sites of RBM10 and its sumoylated form could be targeted for the activated ubiquitin proteasome system. Actinomycin D affected the nuclear speckles localization of RBM10 and RBM5 in COS-7 and A549 lung carcinoma cells. Addition of actinomycin D in the culture medium and following culture for 3〜4 hours promoted the prominent nuclear speckles of RBM10v2-GFP and RBM5. Hence, we explored the subnuclear localization of the full length RBM10v2 (852aa) and the amino terminally truncated forms and the responsible structural elements. The amino terminally truncated RBM10v2 [#486-852, #642-852], RBM10v2 [#648-852], RBM10v2 [#681-759, #681-852], and RBM10v2 [#660-852] retained the targeting elements for the nuclear speckles, nucleoplasm, nucleoli and whole nuclei, respectively.ConclusionRBM10 is highly sensitive to doxorubicin. Actinomycin D affects the structural elements of RBM10 and promotes the nuclear speckles targeting. The C-terminal regions: RBM10v2 [#642-647], [#642-659], and [#660-680] play critical roles in the targeting to the subnuclear compartments. SIM and sumoylation sits of RBM10 and PML4 are important for molecular interaction of RBM10 and PML.


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