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Mir-92 MicroRNA Precursor Family
The miR-92 microRNAs are short single stranded non-protein coding RNA fragments initially discovered incorporated into an RNP complex with a proposed role of processing RNA molecules and further RNP assembly. Mir-92 has been mapped to the human genome as part of a larger cluster at chromosome 13q31.3, where it is 22 nucleotides in length but exists in the genome as part of a longer precursor sequence. There is an exact replica of the mir-92 precursor on the X chromosome. MicroRNAs are endogenous triggers of the RNAi pathway which involves several ribonucleic proteins (RNPs) dedicated to repressing mRNA molecules via translation inhibition and/or induction of mRNA cleavage. miRNAs are themselves matured from their long RNA precursors by ribonucleic proteins as part of a 2 step biogenesis mechanism involving RNA polymerase 2. Most miRNAs are grouped into clusters in the human genome or within families that share functions, expression profiles, promoters, or are incorporated into t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secondary Structure
Protein secondary structure is the three dimensional conformational isomerism, form of ''local segments'' of proteins. The two most common Protein structure#Secondary structure, secondary structural elements are alpha helix, alpha helices and beta sheets, though beta turns and omega loops occur as well. Secondary structure elements typically spontaneously form as an intermediate before the protein protein folding, folds into its three dimensional protein tertiary structure, tertiary structure. Secondary structure is formally defined by the pattern of hydrogen bonds between the Amine, amino hydrogen and carboxyl oxygen atoms in the peptide backbone chain, backbone. Secondary structure may alternatively be defined based on the regular pattern of backbone Dihedral angle#Dihedral angles of proteins, dihedral angles in a particular region of the Ramachandran plot regardless of whether it has the correct hydrogen bonds. The concept of secondary structure was first introduced by Kaj Ulrik ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acute Lymphoblastic Leukemia
Acute lymphoblastic leukemia (ALL) is a cancer of the lymphoid line of blood cells characterized by the development of large numbers of immature lymphocytes. Symptoms may include feeling tired, pale skin color, fever, easy bleeding or bruising, enlarged lymph nodes, or bone pain. As an acute leukemia, ALL progresses rapidly and is typically fatal within weeks or months if left untreated. In most cases, the cause is unknown. Genetic risk factors may include Down syndrome, Li-Fraumeni syndrome, or neurofibromatosis type 1. Environmental risk factors may include significant radiation exposure or prior chemotherapy. Evidence regarding electromagnetic fields or pesticides is unclear. Some hypothesize that an abnormal immune response to a common infection may be a trigger. The underlying mechanism involves multiple genetic mutations that results in rapid cell division. The excessive immature lymphocytes in the bone marrow interfere with the production of new red blood cells, whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microarray
A microarray is a multiplex lab-on-a-chip. Its purpose is to simultaneously detect the expression of thousands of genes from a sample (e.g. from a tissue). It is a two-dimensional array on a solid substrate—usually a glass slide or silicon thin-film cell—that assays (tests) large amounts of biological material using high-throughput screening miniaturized, multiplexed and parallel processing and detection methods. The concept and methodology of microarrays was first introduced and illustrated in antibody microarrays (also referred to as antibody matrix) by Tse Wen Chang in 1983 in a scientific publication and a series of patents. The "gene chip" industry started to grow significantly after the 1995 ''Science Magazine'' article by the Ron Davis and Pat Brown labs at Stanford University. With the establishment of companies, such as Affymetrix, Agilent, Applied Microarrays, Arrayjet, Illumina, and others, the technology of DNA microarrays has become the most sophisticated and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CA-125
Mucin-16 (MUC-16) also known as Ovarian cancer-related tumor marker CA125 is a protein that in humans is encoded by the ''MUC16'' gene. MUC-16 is a member of the mucin family glycoproteins. MUC-16 has found application as a tumor marker or biomarker that may be elevated in the blood of some patients with specific types of cancers, most notably ovarian cancer, or other conditions that are benign. Structure Mucin 16 is a membrane associated mucin that possesses a single transmembrane domain. A unique property of MUC16 is its large size. MUC16 is more than twice as long as MUC1 and MUC4 and contains about 22,000 amino acids, making it the largest membrane-associated mucin. MUC16 is composed of three different domains: * An N-terminal domain * A tandem repeat domain * A C-terminal domain The N-terminal and tandem repeat domains are both entirely extracellular and highly O-glycosylated. All mucins contain a tandem repeat domain that has repeating amino acid sequences high in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Estrogen Receptor Beta
Estrogen receptor beta (ERβ) also known as NR3A2 (nuclear receptor subfamily 3, group A, member 2) is one of two main types of estrogen receptor—a nuclear receptor which is activated by the sex hormone estrogen. In humans ERβ is encoded by the ''ESR2'' gene. Function ERβ is a member of the family of estrogen receptors and the superfamily of nuclear receptor transcription factors. The gene product contains an N-terminal DNA binding domain and C-terminal ligand binding domain and is localized to the nucleus, cytoplasm, and mitochondria. Upon binding to 17-β-estradiol, estriol or related ligands, the encoded protein forms homo-dimers or hetero-dimers with estrogen receptor α that interact with specific DNA sequences to activate transcription. Some isoforms dominantly inhibit the activity of other estrogen receptor family members. Several alternatively spliced transcript variants of this gene have been described, but the full-length nature of some of these variants h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wnt Signaling Pathway
The Wnt signaling pathways are a group of signal transduction pathways which begin with proteins that pass signals into a cell through cell surface receptors. The name Wnt is a portmanteau created from the names Wingless and Int-1. Wnt signaling pathways use either nearby cell-cell communication (paracrine) or same-cell communication (autocrine). They are highly evolutionarily conserved in animals, which means they are similar across animal species from fruit flies to humans. Three Wnt signaling pathways have been characterized: the canonical Wnt pathway, the noncanonical planar cell polarity pathway, and the noncanonical Wnt/calcium pathway. All three pathways are activated by the binding of a Wnt-protein ligand to a Frizzled family receptor, which passes the biological signal to the Dishevelled protein inside the cell. The canonical Wnt pathway leads to regulation of gene transcription, and is thought to be negatively regulated in part by the SPATS1 gene. The noncanonical plana ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mismatch Repair Cancer Syndrome
Mismatch repair cancer syndrome (MMRCS) is a cancer syndrome associated with biallelic DNA mismatch repair mutations. It is also known as Turcot syndrome (after Jacques Turcot, who described the condition in 1959) and by several other names. In MMRCS, neoplasia typically occurs in both the gut and the central nervous system (CNS). In the large intestine, multiple colonic polyps develop; in the CNS, brain tumors. Genetics Under the name constitutional mismatch repair-deficiency, (CMMR-D), it has been mapped to MLH1, MSH2, MSH6 or PMS2. Monoallelic mutations of these genes are observed in the condition known as Lynch syndrome or hereditary nonpolyposis colorectal cancer, while biallelic mutations are observed in CMMR-D. People expressing the HNPCC (which itself is considered autosomal dominant) trait are considered carriers of CMMR-D, thus CMMR-D is classified as autosomal recessive. The term "childhood cancer syndrome" has also been proposed. Café-au-lait macules have been obser ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sonic Hedgehog
Sonic hedgehog protein (SHH) is encoded for by the ''SHH'' gene. The protein is named after the character ''Sonic the Hedgehog''. This signaling molecule is key in regulating embryonic morphogenesis in all animals. SHH controls organogenesis and the organization of the central nervous system, limbs, digits and many other parts of the body. Sonic hedgehog is a morphogen that patterns the developing embryo using a concentration gradient characterized by the French flag model. This model has a non-uniform distribution of SHH molecules which governs different cell fates according to concentration. Mutations in this gene can cause holoprosencephaly, a failure of splitting in the cerebral hemispheres, as demonstrated in an experiment using SHH knock-out mice in which the forebrain midline failed to develop and instead only a single fused telencephalic vesicle resulted. Sonic hedgehog still plays a role in differentiation, proliferation, and maintenance of adult tissues. Abnormal activ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Patched
Patched (Ptc) is a conserved 12-pass transmembrane protein receptor that plays an obligate negative regulatory role in the Hedgehog signaling pathway in insects and vertebrates. Patched is an essential gene in embryogenesis for proper segmentation in the fly embryo, mutations in which may be embryonic lethal. Patched functions as the receptor for the Hedgehog protein and controls its spatial distribution, in part via endocytosis of bound Hedgehog protein, which is then targeted for lysosomal degradation. Discovery The original mutations in the ''ptc'' gene were discovered in the fruit fly ''Drosophila melanogaster'' by 1995 Nobel Laureates Eric F. Wieschaus and Christiane Nusslein-Volhard and colleagues, and the gene was independently cloned in 1989 by Joan Hooper in the laboratory of Matthew P. Scott, and by Philip Ingham and colleagues. Role in hedgehog signaling Patched is part of a negative feedback mechanism for hedgehog signaling that helps shape the sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nevoid Basal Cell Carcinoma Syndrome
Nevoid basal-cell carcinoma syndrome (NBCCS) is an inherited medical condition involving defects within multiple body systems such as the skin, nervous system, eyes, endocrine system, and bones. People with this syndrome are particularly prone to developing a common and usually non-life-threatening form of non-melanoma skin cancer. About 10% of people with the condition do not develop basal-cell carcinomas (BCCs). The name ''Gorlin syndrome'' refers to the American oral pathologist and human geneticist Robert J. Gorlin (1923–2006). The American dermatologist Robert W. Goltz (1923–2014)Burgdorf WH, Padilla RS, Hordinsky M. In memoriam: Robert W. Goltz (1923-2014). J Am Acad Dermatol 2014; 71: e163–e165 was his co-author, which is the basis for the term 'Gorlin-Goltz syndrome'. First described in 1960 by Gorlin and Goltz, NBCCS is an autosomal dominant condition that can cause unusual facial appearances and a predisposition for basal-cell carcinoma, a type of skin cancer whic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medulloblastoma
Medulloblastoma is a common type of primary brain cancer in children. It originates in the part of the brain that is towards the back and the bottom, on the floor of the skull, in the cerebellum, or posterior fossa. The brain is divided into two main parts, the larger cerebrum on top and the smaller cerebellum below towards the back. They are separated by a membrane called the tentorium. Tumors that originate in the cerebellum or the surrounding region below the tentorium are, therefore, called infratentorial. Historically medulloblastomas have been classified as a primitive neuroectodermal tumor (PNET), but it is now known that medulloblastoma is distinct from supratentorial PNETs and they are no longer considered similar entities. Medulloblastomas are invasive, rapidly growing tumors that, unlike most brain tumors, spread through the cerebrospinal fluid and frequently metastasize to different locations along the surface of the brain and spinal cord. Metastasis all the way dow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mir-19 MicroRNA Precursor Family
There are 89 known sequences today in the microRNA 19 (miR-19) family but it will change quickly. They are found in a large number of vertebrate species. The miR-19 microRNA precursor is a small non-coding RNA molecule that regulates gene expression. Within the human and mouse genome there are three copies of this microRNA that are processed from multiple predicted precursor hairpins: * mouse: : * miR-19a on chromosome 14MI0000688 : * miR-19b-1 on chromosome 14MI0000718 : * miR-19b-2 on chromosome XMI0000546 * human: : * miR-19a on chromosome 13MI0000073 : * miR-19b-1 on chromosome 13MI0000074 : * miR-19b-2 on chromosome XMI000075. MiR-19 has now been predicted or experimentally confirmed MIPF0000011. In this case the mature sequence is excised from the 3' arm of the hairpin precursor. Origins MicroRNA are ubiquitous in higher eukaryotes, and show varying patterns of expression in specific cell types. MiR-19 has been identified in a diverse range of vertebrate animals includin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
