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Triapine
3-Aminopyridine-2-carboxaldehyde thiosemicarbazone (3-AP, also called Triapine) is a substance that is being studied in the treatment of cancer. It belongs to the family of drugs called ribonucleotide reductase inhibitors. 3AP is a potent inhibitor of ribonucleotide reductase, the rate determining enzyme in the supply of deoxynucleotides (DNA building blocks) for DNA synthesis. DNA synthesis is required for cellular proliferation and DNA repair. It is a very strong iron chelator and in the body it is likely that the iron chelate is the active species that quenches the active site tyrosyl radical required by ribonucleotide reductase for its enzymatic activity. The 3AP iron chelate is redox active and there have been several reports in the literature ascribing this property to some of the biological activities of 3AP. 3AP was chosen, based on the results of studying and the screening these products, as the candidate inhibitor most likely to express activity in the setting of human ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ribonucleotide Reductase Inhibitor
Ribonucleotide reductase inhibitors are a family of anti-cancer drugs that interfere with the growth of tumor cells by blocking the formation of deoxyribonucleotides (building blocks of DNA). Examples include: * motexafin gadolinium. * hydroxyurea * fludarabine, cladribine, gemcitabine, tezacitabine, and triapine * gallium maltolate, gallium nitrate See also * Ribonucleotide reductase Ribonucleotide reductase (RNR), also known as ribonucleoside diphosphate reductase (rNDP), is an enzyme that catalyzes the formation of deoxyribonucleotides from ribonucleotides. It catalyzes this formation by removing the 2'-hydroxyl group of th ... References External links Ribonucleotide reductase inhibitorentry in the public domain NCI Dictionary of Cancer Terms Antineoplastic drugs Oxidoreductase inhibitors {{Antineoplastic-drug-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cancer
Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal bleeding, prolonged cough, unexplained weight loss, and a change in bowel movements. While these symptoms may indicate cancer, they can also have other causes. Over 100 types of cancers affect humans. Tobacco use is the cause of about 22% of cancer deaths. Another 10% are due to obesity, poor diet, lack of physical activity or excessive drinking of alcohol. Other factors include certain infections, exposure to ionizing radiation, and environmental pollutants. In the developing world, 15% of cancers are due to infections such as ''Helicobacter pylori'', hepatitis B, hepatitis C, human papillomavirus infection, Epstein–Barr virus and human immunodeficiency virus (HIV). These factors act, at least partly, by changing the genes of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DNA Synthesis
DNA synthesis is the natural or artificial creation of deoxyribonucleic acid (DNA) molecules. DNA is a macromolecule made up of nucleotide units, which are linked by covalent bonds and hydrogen bonds, in a repeating structure. DNA synthesis occurs when these nucleotide units are joined to form DNA; this can occur artificially (''in vitro'') or naturally (''in vivo''). Nucleotide units are made up of a nitrogenous base (cytosine, guanine, adenine or thymine), pentose sugar (deoxyribose) and phosphate group. Each unit is joined when a covalent bond forms between its phosphate group and the pentose sugar of the next nucleotide, forming a sugar-phosphate backbone. DNA is a complementary, double stranded structure as specific base pairing (adenine and thymine, guanine and cytosine) occurs naturally when hydrogen bonds form between the nucleotide bases. There are several different definitions for DNA synthesis: it can refer to DNA replication - DNA biosynthesis (''in vivo'' DNA amplific ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DNA Repair
DNA repair is a collection of processes by which a cell identifies and corrects damage to the DNA molecules that encode its genome. In human cells, both normal metabolic activities and environmental factors such as radiation can cause DNA damage, resulting in tens of thousands of individual molecular lesions per cell per day. Many of these lesions cause structural damage to the DNA molecule and can alter or eliminate the cell's ability to transcribe the gene that the affected DNA encodes. Other lesions induce potentially harmful mutations in the cell's genome, which affect the survival of its daughter cells after it undergoes mitosis. As a consequence, the DNA repair process is constantly active as it responds to damage in the DNA structure. When normal repair processes fail, and when cellular apoptosis does not occur, irreparable DNA damage may occur, including double-strand breaks and DNA crosslinkages (interstrand crosslinks or ICLs). This can eventually lead to malignant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vion Pharmaceuticals
Vion Pharmaceuticals, Inc. was a New Haven, Connecticut based pharmaceutical company founded in March 1992 to commercialize several discoveries made in the biomedical laboratories at Yale University. Clinical development Two anticancer agents, Onrigin (laromustine), formerly cloretazine (VNP40101M), and Triapine, a ribunucloetide reductase inhibitor similar to hydroxyurea, were in human clinical trials. A novel alkylating agent, Onrigin was evaluated in a Phase 2 trial in elderly ''de novo'' poor-risk acute myeloid leukemia (AML). In addition, several trials of Onrigin were conducted in elderly patients with AML and myelodysplastic syndrome (MDS) in combination with cytarabine, and in patients with brain tumors in combination with temozolomide. Bankruptcy After Onrigin was rejected by the Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of H ... [...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] |
Thiosemicarbazone
A thiosemicarbazone is an organosulfur compound with the formula H2NC(S)NHN=CR2. Many variations exist, including those where some or all of the N''H'' centers are substituted by organic groups. Thiosemicarbazones are usually produced by condensation of a thiosemicarbazide with an aldehyde or ketone: : H2NC(S)NHNH2 + O=CR2 → H2NC(S)NHN=CR2 + H2O In terms of their chemical structures, the CSN3 core atoms are coplanar. Occurrence and applications Some thiosemicarbazones have medicinal properties, e.g. the antiviral metisazone and the antibiotic thioacetazone. Thiosemicarbazones are also widely used as ligands in coordination chemistry A coordination complex consists of a central atom or ion, which is usually metallic and is called the ''coordination centre'', and a surrounding array of bound molecules or ions, that are in turn known as ''ligands'' or complexing agents. Many .... The affinity of thiosemicarbazones for metal ions is exploited in controlling iron ove ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
