Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.26.9 (ribonuclease)
 6,589 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Several newly synthesized boron betaine analogs had antitumor activity in Ehrlich ascites, Walker 256 ascites carcinosarcoma, and Lewis lung screens and marginal activity in the B-16 melanotic melanoma screen. In vivo testing demonstrated that trimethylamine-cyanoborane inhibied Ehrlich ascites cell DNA and protein syntheses as well as gene modulation by chromatin protein phosphorylation and methylation. Trimethylamine-cyanoborane increased cyclic-AMP levels. In vitro testing showed that nuclear DNA polymerase, thymidylate synthetase, S-adenosylmethyltransferase, nonhistone chromatin methylation, deoxyribonuclease, ribonuclease, and cathepsin were inhibited by the boron analogs. These compounds did not demonstrate high antitumor activity at the doses employed, but blockage of methyl transfer from S-adenosylmethionine was established as a feasible method for controlling cell proliferation.
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PMID:Boron betaine analogs: antitumor activity and effects on Ehrlich ascites tumor cell metabolism. 22 87

To investigate the possibility that mitochondrial transcription could be altered in tumours we started by characterizing the RNA obtained from mitochondria, isolated from Walker carcinosarcoma and purified by a procedure devised to compensate for the lower size and density of these organelles in 10-day tumours. The RNA was extracted by the 'hot phenol' technique and analysed by electrophoresis in 2.7 and 2.5% polyacrylamide gels at different running times, identifying the usual cytoplasmic contaminants 28 and 18S peaks plus the other five major peaks at 40, 20.5, 16.3, 15.4, and 4Se. The 28 and 18Se peaks were not eliminated by digitonin treatment of the mitochondria, indicating that they arise from cytoplasmic ribosomes tightly associated with the mitochondria. From its sensitivity to DNAase (deoxyribonuclease), resistance to RNAase (ribonuclease) and coincidence with external marker DNA, the 40Se peak was identified as containing mainly DNA. Sucrosegradient centrifugation for different periods showed a major component at 16.2S, the 28 and 18S cytoplasmic RNA species, peaks at 13.8, 6.4 and 4S and a small 19.5S peak. By polyacrylamide-gel electrophoresis of the purified RNA classes separated by one or two cycles of centrifugation, the following correlation were established: 20.5Se19.5S; 16.3Se16.2S; 15.4Se13.8S. The 6.4S RNA ran as a mixture of 4 and 4.7Se species. When the 20.5Se and 15.4Se RNA species were centrifuged, they behaved as 16.2S and 13.8S respectively, thus suggesting that the 16.2S (16.3Se) arises by cleavage from the 19.5S(20.5Se), the 13.8S (15.4Se) being the other RNA from mitochondrial ribosomes.
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PMID:Electrophoretic and centrifugation behaviour of mitochondrial ribonucleic acid from Walker 256 carcinosarcoma. 115 77

The complete nucleotide sequences of human placenta, human liver, and bovine liver tRNAAsn have been determined. A comparison of these tRNA structures with the previously reported nucleotide sequences of rat liver and Walker 256 carcinosarcoma tRNAAns reveals that the primary nucleotide sequences of the major species of mammalian cytoplasmic tRNAasn are conserved in higher eucaryotes. The complete nucleotide sequence of these tRNAs is: pG-U-C-U-C-U-G-U-m1G-m2G-C-G-C-A-A-D-C-G-G-D-X-A-G-C-G-C-m2(2)G-psi-psi-C-G-G-C-U-Q(G)-U-U-t6A-A-C-C-G-A-A-A-G-m7G-D-U-G-G-U-G-G-Z-psi-C-G-m1A-G-C-C-C-A-C-C-C-A-G-G-G-A-C-G-C-C-AOH where X is 3-(3-amino-3-carboxyl-n-propyl)uridine, Q is 7-(4,5-cis-dihydroxyl-1-cyclopenten-3-yl-aminomethyl)-7-deazaguanosine, Z is an unknown modified nucleotide, and Q(G) represents the replacement of Q nucleoside by G nucleoside in Walker 256 carcinosarcoma tRNAAsn. These primary structures were determined by combined use of the 3H- and 32P-post-labeling techniques. Sequences were compared by tritium nucleoside trialcohol analysis, completed RNAase T1 digestion followed by 3H-labeled fingerprinting on polyethylenimine-impregnated cellulose by two-dimensional thin-layer chromatography (TLC), and polyacrylamide gel electrophoresis of either 5'-32P- and/or 3'-[32P]pCp-labeled tRNA after partial ribonuclease digestions.
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PMID:Structural comparison of human, bovine, rat, and Walker 256 carcinosarcoma asparaginyl-tRNA. 678 75