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Rebeccamycin
Rebeccamycin (NSC 655649) is a weak topoisomerase I inhibitor isolated from ''Nocardia sp.'' It is structurally similar to staurosporine, but does not show any inhibitory activity against protein kinases. It shows significant antitumor properties in vitro (IC50=480nM against mouse B16 melanoma cells and IC50=500nM against P388 The NCI-60 cancer cell line panel is a group of 60 human cancer cell lines used by the National Cancer Institute (NCI) for the screening of compounds to detect potential anticancer activity. Purpose The screening procedure is called the NCI- ... leukemia cells). It is an antineoplastic antibiotic and an intercalating agent. Becatecarin (BMS-181176) is a synthetic analog of rebeccamycin. Rebeccamycin and becatecarin have been tested in phase II clinical trials for the treatment of lung cancer, liver cancer, breast cancer, lymphoma, retinoblastoma, kidney cancer, and ovarian cancer. References Further reading * * * * * Experimental canc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Staurosporine
Staurosporine (antibiotic AM-2282 or STS) is a natural product originally isolated in 1977 from the bacterium '' Streptomyces staurosporeus''. It was the first of over 50 alkaloids to be isolated with this type of bis-indole chemical structure. The chemical structure of staurosporine was elucidated by X-ray analysis of a single crystal and the absolute stereochemical configuration by the same method in 1994. Staurosporine was discovered to have biological activities ranging from anti-fungal to anti-hypertensive. The interest in these activities resulted in a large investigative effort in chemistry and biology and the discovery of the potential for anti-cancer treatment. Biological activities The main biological activity of staurosporine is the inhibition of protein kinases through the prevention of ATP binding to the kinase. This is achieved through the stronger affinity of staurosporine to the ATP-binding site on the kinase. Staurosporine is a prototypical ATP-competitive kinase ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Topoisomerase
DNA topoisomerases (or topoisomerases) are enzymes that catalyze changes in the topological state of DNA, interconverting relaxed and supercoiled forms, linked (catenated) and unlinked species, and knotted and unknotted DNA. Topological issues in DNA arise due to the intertwined nature of its double-helical structure, which, for example, can lead to overwinding of the DNA duplex during DNA replication and transcription. If left unchanged, this torsion would eventually stop the DNA or RNA polymerases involved in these processes from continuing along the DNA helix. A second topological challenge results from the linking or tangling of DNA during replication. Left unresolved, links between replicated DNA will impede cell division. The DNA topoisomerases prevent and correct these types of topological problems. They do this by binding to DNA and cutting the sugar-phosphate backbone of either one (type I topoisomerases) or both (type II topoisomerases) of the DNA strands. This transie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nocardia
''Nocardia'' is a genus of weakly staining Gram-positive, catalase-positive, rod-shaped bacteria. It forms partially acid-fast beaded branching filaments (acting as fungi, but being truly bacteria). It contains a total of 85 species. Some species are nonpathogenic, while others are responsible for nocardiosis. ''Nocardia'' species are found worldwide in soil rich in organic matter. In addition, they are oral microflora found in healthy gingiva, as well as periodontal pockets. Most ''Nocardia'' infections are acquired by inhalation of the bacteria or through traumatic introduction. Culture and staining ''Nocardia'' colonies have a variable appearance, but most species appear to have aerial hyphae when viewed with a dissecting microscope, particularly when they have been grown on nutritionally limiting media. ''Nocardia'' grow slowly on nonselective culture media, and are strict aerobes with the ability to grow in a wide temperature range. Some species are partially acid-f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Kinases
A protein kinase is a kinase which selectively modifies other proteins by covalently adding phosphates to them (phosphorylation) as opposed to kinases which modify lipids, carbohydrates, or other molecules. Phosphorylation usually results in a functional change of the target protein ( substrate) by changing enzyme activity, cellular location, or association with other proteins. The human genome contains about 500 protein kinase genes and they constitute about 2% of all human genes. There are two main types of protein kinase. The great majority are serine/threonine kinases, which phosphorylate the hydroxyl groups of serines and threonines in their targets and most of the others are tyrosine kinases, although additional types exist. Protein kinases are also found in bacteria and plants. Up to 30% of all human proteins may be modified by kinase activity, and kinases are known to regulate the majority of cellular pathways, especially those involved in signal transduction. Chemical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
P388
The NCI-60 cancer cell line panel is a group of 60 human cancer cell lines used by the National Cancer Institute (NCI) for the screening of compounds to detect potential anticancer activity. Purpose The screening procedure is called the NCI-60 Human Tumor Cell Lines Screen, and it is one of the Discovery & Development Services of NCI's Developmental Therapeutics Program (DTP). The screening rates for each cell line the cytostatic and cytotoxic impact of tested substances. Due to the diversity of the cell lines, it is possible to compare tested compounds by their effect patterns, high correlation potentially corresponding to similar effect mechanisms. An automated comparison against a database of more than 88,000 pure compounds and more than 34,000 crude extracts () is provided by the COMPARE tool, which shows a list of substances ranked by the Pearson correlation coefficients for a given test substance. The same panel is used in the Molecular Target Program for t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Experimental Cancer Drugs
An experiment is a procedure carried out to support or refute a hypothesis, or determine the efficacy or likelihood of something previously untried. Experiments provide insight into cause-and-effect by demonstrating what outcome occurs when a particular factor is manipulated. Experiments vary greatly in goal and scale but always rely on repeatable procedure and logical analysis of the results. There also exist natural experimental studies. A child may carry out basic experiments to understand how things fall to the ground, while teams of scientists may take years of systematic investigation to advance their understanding of a phenomenon. Experiments and other types of hands-on activities are very important to student learning in the science classroom. Experiments can raise test scores and help a student become more engaged and interested in the material they are learning, especially when used over time. Experiments can vary from personal and informal natural comparisons (e. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Topoisomerase Inhibitors
DNA topoisomerases (or topoisomerases) are enzymes that catalyze changes in the topological state of DNA, interconverting relaxed and supercoiled forms, linked (catenated) and unlinked species, and knotted and unknotted DNA. Topological issues in DNA arise due to the intertwined nature of its double-helical structure, which, for example, can lead to overwinding of the DNA duplex during DNA replication and transcription. If left unchanged, this torsion would eventually stop the DNA or RNA polymerases involved in these processes from continuing along the DNA helix. A second topological challenge results from the linking or tangling of DNA during replication. Left unresolved, links between replicated DNA will impede cell division. The DNA topoisomerases prevent and correct these types of topological problems. They do this by binding to DNA and cutting the sugar-phosphate backbone of either one (type I topoisomerases) or both (type II topoisomerases) of the DNA strands. This transie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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