In vitro Effect of Sodium Warfarin on DNA and RNA Synthesis of Mouse L1210 Leukemic Cells and Walker Tumor Cells

Oncology ◽  
1973 ◽  
Vol 28 (3) ◽  
pp. 232-237 ◽  
Author(s):  
J.C. Chang ◽  
T.C. Hall
1992 ◽  
Vol 284 (1) ◽  
pp. 47-52 ◽  
Author(s):  
P Landini ◽  
E Corti ◽  
B P Goldstein ◽  
M Denaro

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.


1989 ◽  
Vol 22 (1) ◽  
pp. 91-94 ◽  
Author(s):  
M. Nakamura ◽  
N. Nonomura ◽  
M. Namiki ◽  
A. Okuyama ◽  
E. Koh ◽  
...  

Author(s):  
Mayur S. Jain ◽  
Mayur R. Bhurat ◽  
Sunil R Bavaskar

Melphalan Flufenamide is a peptide-drug conjugate composed of a peptide conjugated, via an aminopeptidase-targeting linkage, to the alkylating agent melphalan, with potential antineoplastic and anti-angiogenic activities. Upon administration, the highly lipophilic melphalan flufenamide penetrates cell membranes and enters cells. In aminopeptidase-positive tumor cells, melphalan flufenamide is hydrolyzed by peptidases to release the hydrophilic alkylating agent melphalan. This results in the specific release and accumulation of melphalan in aminopeptidase-positive tumor cells. Melphalan alkylates DNA at the N7 position of guanine residues and induces DNA intra- and inter-strand cross-linkages. This results in the inhibition of DNA and RNA synthesis and the induction of apoptosis, thereby inhibiting tumor cell proliferation. Peptidases are overexpressed by certain cancer cells. The administration of melphalan flufenamide allows for enhanced efficacy and reduced toxicity compared to melphalan.1,2,3


1967 ◽  
Vol 125 (5) ◽  
pp. 863-872 ◽  
Author(s):  
Douglass C. Tormey ◽  
Roberta Kamin ◽  
H. Hugh Fudenberg

Leukocytes from nine patients with acquired agammaglobulinemia were studied in vitro. Synthesis of deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) induced by phytohemagglutinin was measured by determination of the degree of incorporation of labeled precursor. Synthesis of both DNA and RNA was decreased in the agammaglobulinemic cells. The presence of an inhibitor in the patients' sera could not be demonstrated. These results suggest that the basic defect in agammaglobulinemia is cellular rather than humoral.


2020 ◽  
Vol 21 (19) ◽  
pp. 7084
Author(s):  
Fabiana da Silva Lima ◽  
Ricardo Ambrósio Fock

Magnesium (Mg2+) is an essential mineral for the functioning and maintenance of the body. Disturbances in Mg2+ intracellular homeostasis result in cell-membrane modification, an increase in oxidative stress, alteration in the proliferation mechanism, differentiation, and apoptosis. Mg2+ deficiency often results in inflammation, with activation of inflammatory pathways and increased production of proinflammatory cytokines by immune cells. Immune cells and others that make up the blood system are from hematopoietic tissue in the bone marrow. The hematopoietic tissue is a tissue with high indices of renovation, and Mg2+ has a pivotal role in the cell replication process, as well as DNA and RNA synthesis. However, the impact of the intra- and extracellular disturbance of Mg2+ homeostasis on the hematopoietic tissue is little explored. This review deals specifically with the physiological requirements of Mg2+ on hematopoiesis, showing various studies related to the physiological requirements and the effects of deficiency or excess of this mineral on the hematopoiesis regulation, as well as on the specific process of erythropoiesis, granulopoiesis, lymphopoiesis, and thrombopoiesis. The literature selected includes studies in vitro, in animal models, and in humans, giving details about the impact that alterations of Mg2+ homeostasis can have on hematopoietic cells and hematopoietic tissue.


1992 ◽  
Vol 65 (1) ◽  
pp. 43-49 ◽  
Author(s):  
Fikrat I. Abdullaev ◽  
Christina MacVicar ◽  
Gerald D. Frenkel

Blood ◽  
1966 ◽  
Vol 27 (3) ◽  
pp. 310-318 ◽  
Author(s):  
JAKOB R. SCHMID ◽  
JOSEPH M. KIELY ◽  
W. NEWLON TAUXE ◽  
CHARLES A. OWEN

Abstract In 12 normal subjects, DNA and RNA synthesis by individual marrow cells was studied in vitro by autoradiography after short-term incubation with tritiated nucleosides. The DNA labeling index and RNA synthesis rate were highest in normal immature cells. The DNA index was zero in all mature cells, including small lymphocytes and plasma cells. In the most actively proliferating normal immature cells, the RNA synthesis rate was about 5 times higher than in normal plasma cells. Since both normal immature cells and plasma cells are characterized by a high content of RNA and active protein synthesis, the results of the present study suggest that a high RNA turnover may not be necessary for protein synthesis to proceed in nonproliferating, protein-producing marrow cells. In 10 patients with myeloma and in two patients with primary macroglobulinemia, the abnormal plasma cells were found to be labeled with H3thymidine in each instance. The RNA synthesis rate was about 3 times greater in plasmocytoid myeloma cells than in mature plasma cells of normal marrows, and also about 3 times greater in lymphocytoid myeloma cells than in mature lymphocytes of normal marrows. The abnormal cells in the lymphoplasmocytic disorders apparently differ from their counterparts in normal marrows not only by a higher proliferative potential, but also by a much greater rate of RNA synthesis. In actively dividing normal bone marrow cells, high values for both DNA and RNA synthesis were found. By contrast, in the neoplastic lymphoplasma cells studied, a discrepancy was noted between relatively low values of DNA synthesis and high values of RNA synthesis. Production of abnormal proteins within long-lived neoplastic plasmocytic cells may account for this finding.


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