Virtual screeningVirtual screening (VS) is a computational technique used in drug discovery to search libraries of small molecules in order to identify those structures which are most likely to bind to a drug target, typically a protein receptor or enzyme. Virtual screening has been defined as "automatically evaluating very large libraries of compounds" using computer programs. As this definition suggests, VS has largely been a numbers game focusing on how the enormous chemical space of over 1060 conceivable compounds can be filtered to a manageable number that can be synthesized, purchased, and tested.
Cancer immunotherapyCancer immunotherapy (sometimes called immuno-oncology) is the stimulation of the immune system to treat cancer, improving on the immune system's natural ability to fight the disease. It is an application of the fundamental research of cancer immunology and a growing subspecialty of oncology. Cancer immunotherapy exploits the fact that cancer cells often have tumor antigens, molecules on their surface that can be detected by the antibody proteins of the immune system, binding to them.
Chemical warfareChemical warfare (CW) involves using the toxic properties of chemical substances as weapons. This type of warfare is distinct from nuclear warfare, biological warfare and radiological warfare, which together make up CBRN, the military acronym for chemical, biological, radiological, and nuclear (warfare or weapons), all of which are considered "weapons of mass destruction" (WMDs), a term that contrasts with conventional weapons. The use of chemical weapons is prohibited under customary international humanitarian law.
EpistasisEpistasis is a phenomenon in genetics in which the effect of a gene mutation is dependent on the presence or absence of mutations in one or more other genes, respectively termed modifier genes. In other words, the effect of the mutation is dependent on the genetic background in which it appears. Epistatic mutations therefore have different effects on their own than when they occur together. Originally, the term epistasis specifically meant that the effect of a gene variant is masked by that of a different gene.
Chemical weaponA chemical weapon (CW) is a specialized munition that uses chemicals formulated to inflict death or harm on humans. According to the Organisation for the Prohibition of Chemical Weapons (OPCW), this can be any chemical compound intended as a weapon "or its precursor that can cause death, injury, temporary incapacitation or sensory irritation through its chemical action. Munitions or other delivery devices designed to deliver chemical weapons, whether filled or unfilled, are also considered weapons themselves.
Cancer epigeneticsCancer epigenetics is the study of epigenetic modifications to the DNA of cancer cells that do not involve a change in the nucleotide sequence, but instead involve a change in the way the genetic code is expressed. Epigenetic mechanisms are necessary to maintain normal sequences of tissue specific gene expression and are crucial for normal development. They may be just as important, if not even more important, than genetic mutations in a cell's transformation to cancer.
Chromatin remodelingChromatin remodeling is the dynamic modification of chromatin architecture to allow access of condensed genomic DNA to the regulatory transcription machinery proteins, and thereby control gene expression. Such remodeling is principally carried out by 1) covalent histone modifications by specific enzymes, e.g., histone acetyltransferases (HATs), deacetylases, methyltransferases, and kinases, and 2) ATP-dependent chromatin remodeling complexes which either move, eject or restructure nucleosomes.
Poly (ADP-ribose) polymerasePoly (ADP-ribose) polymerase (PARP) is a family of proteins involved in a number of cellular processes such as DNA repair, genomic stability, and programmed cell death. The PARP family comprises 17 members (10 putative). They vary greatly in structure and function within the cell. PARP1, PARP2, VPARP (PARP4), Tankyrase-1 and -2 (PARP-5a or TNKS, and PARP-5b or TNKS2) have a confirmed PARP activity. Others include PARP3, , TIPARP (or "PARP7"), PARP8, , PARP10, , PARP12, , , and PARP16.
Small moleculeIn molecular biology and pharmacology, a small molecule or micromolecule is a low molecular weight (≤ 1000 daltons) organic compound that may regulate a biological process, with a size on the order of 1 nm. Many drugs are small molecules; the terms are equivalent in the literature. Larger structures such as nucleic acids and proteins, and many polysaccharides are not small molecules, although their constituent monomers (ribo- or deoxyribonucleotides, amino acids, and monosaccharides, respectively) are often considered small molecules.
ChromatinChromatin is a complex of DNA and protein found in eukaryotic cells. The primary function is to package long DNA molecules into more compact, denser structures. This prevents the strands from becoming tangled and also plays important roles in reinforcing the DNA during cell division, preventing DNA damage, and regulating gene expression and DNA replication. During mitosis and meiosis, chromatin facilitates proper segregation of the chromosomes in anaphase; the characteristic shapes of chromosomes visible during this stage are the result of DNA being coiled into highly condensed chromatin.
CamptothecinCamptothecin (CPT) is a topoisomerase inhibitor. It was discovered in 1966 by M. E. Wall and M. C. Wani in systematic screening of natural products for anticancer drugs. It was isolated from the bark and stem of Camptotheca acuminata (Camptotheca, Happy tree), a tree native to China used in traditional Chinese medicine. It has been used clinically more recently in China for the treatment of gastrointestinal tumors. CPT showed anticancer activity in preliminary clinical trials, especially against breast, ovarian, colon, lung, and stomach cancers.
NucleoproteinNucleoproteins are proteins conjugated with nucleic acids (either DNA or RNA). Typical nucleoproteins include ribosomes, nucleosomes and viral nucleocapsid proteins. Nucleoproteins tend to be positively charged, facilitating interaction with the negatively charged nucleic acid chains. The tertiary structures and biological functions of many nucleoproteins are understood. Important techniques for determining the structures of nucleoproteins include X-ray diffraction, nuclear magnetic resonance and cryo-electron microscopy.
