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Cyclopamine
Cyclopamine (11-deoxojervine) is a naturally occurring chemical that belongs in the family of steroidal alkaloids. It is a teratogen isolated from the corn lily (''Veratrum californicum'') that causes fatal birth defects. It prevents the embryonic brain from separating into two lobes (an extreme form of holoprosencephaly), which in turn causes the development of a single eye (cyclopia). The chemical was named after this effect, as it was originally noted by Idaho lamb farmers who contacted the US Department of Agriculture after their herds gave birth to cycloptic lambs in 1957. It then took more than a decade to identify the corn lily as the culprit. Later work suggested that different rain patterns caused the sheep to graze differently, impacting the amount of corn lily ingested by pregnant sheep. The poison interrupts the sonic hedgehog signaling pathway during development, thus causing birth defects. Discovery and naming In 1957, Idaho sheep ranchers contacted the US Departm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclopamine In Smoothened Receptor
Cyclopamine (11-deoxojervine) is a naturally occurring chemical that belongs in the family of steroidal alkaloids. It is a teratogen isolated from the corn lily (''Veratrum californicum'') that causes fatal birth defects. It prevents the embryonic brain from separating into two lobes (an extreme form of holoprosencephaly), which in turn causes the development of a single eye (cyclopia). The chemical was named after this effect, as it was originally noted by Idaho lamb farmers who contacted the US Department of Agriculture after their herds gave birth to cycloptic lambs in 1957. It then took more than a decade to identify the corn lily as the culprit. Later work suggested that different rain patterns caused the sheep to graze differently, impacting the amount of corn lily ingested by pregnant sheep. The poison interrupts the sonic hedgehog signaling pathway during development, thus causing birth defects. Discovery and naming In 1957, Idaho sheep ranchers contacted the US Depart ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smoothened
Smoothened is a protein that in humans is encoded by the SMO gene. Smoothened is a Class Frizzled (Class F) G protein-coupled receptor that is a component of the hedgehog signaling pathway and is conserved from flies to humans. It is the molecular target of the natural teratogen cyclopamine. It also is the target of vismodegib, the first hedgehog pathway inhibitor to be approved by the U.S. Food and Drug Administration (FDA). Smoothened (Smo) is a key transmembrane protein that is a key component of the hedgehog signaling pathway, a cell-cell communication system critical for embryonic development and adult tissue homeostasis. Mutations in proteins that relay Hh signals between cells cause birth defects and cancer. The protein that carries the Hh signal across the membrane is the oncoprotein and G-protein coupled receptor (GPCR) Smoothened (Smo). Smo is regulated by a separate transmembrane receptor for Hh ligands called Patched (Ptc). Ptc itself is a tumor suppressor that keeps ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jervine
Jervine is a steroidal alkaloid with molecular formula C27H39NO3 which is derived from the plant genus ''Veratrum''. Similar to cyclopamine, which also occurs in the genus ''Veratrum'', it is a teratogen implicated in birth defects when consumed by animals during a certain period of their gestation. Physiological effects Jervine is a potent teratogen causing birth defects in vertebrates. In severe cases it can cause cyclopia and holoprosencephaly. Mechanism of action Jervine's biological activity is mediated via its interaction with the 7 pass trans membrane protein smoothened. Jervine binds with and inhibits smoothened, which is an integral part of the hedgehog signaling pathways. With smoothened inhibited, the GLI1 Zinc finger protein GLI1 also known as glioma-associated oncogene is a protein that in humans is encoded by the GLI1 gene. It was originally isolated from human glioblastoma cells. Function The Gli proteins are the effectors of Hedgehog (Hh) ... transcrip ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vismodegib
Vismodegib (trade name Erivedge ) is a drug for the treatment of basal-cell carcinoma (BCC). The approval of vismodegib on January 30, 2012, represents the first Hedgehog signaling pathway targeting agent to gain U.S. Food and Drug Administration (FDA) approval. The drug is also undergoing clinical trials for metastatic colorectal cancer, small-cell lung cancer, advanced stomach cancer, pancreatic cancer, medulloblastoma and chondrosarcoma . The drug was developed by the biotechnology/pharmaceutical company Genentech. Indication Vismodegib is indicated for patients with basal-cell carcinoma (BCC) which has metastasized to other parts of the body, relapsed after surgery, or cannot be treated with surgery or radiation. Mechanism of action The substance acts as a cyclopamine-competitive antagonist of the smoothened receptor (SMO) which is part of the Hedgehog signaling pathway. SMO inhibition causes the transcription factors GLI1 and GLI2 to remain inactive, which prevents t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steroidal Alkaloid
Steroidal alkaloids have organic ring backbones which feature nitrogen-based functional groups. More specifically, they are distinguished by their tetracyclic cyclopentanophenanthrene backbone that marks their close relationship with sterols. They fall in two major categories: Solanum alkaloids and Veratrum alkaloids. A Steroidal alkaloid has also been found in ''Chonemorpha fragrans'' (Frangipani vine), 'chonemorphine' was used to treat intestinal infections in Wistar rats. (Chatterjee DK et al (1987) Parasitol Res 74, 1, 30-33). ''Solanum'' alkaloids These compounds generally appear as their corresponding glycoside in plants of the genus ''Solanum''. ''Solanum'' includes plants like potatoes, tomatoes, and various nightshades Starting with cholesterol, the biosynthesis of these compounds follow a similar general mechanism including hydroxylation, oxidation, and transamination before differentiating. Alkaloids found in these plants include chaconine, solanine, solasodine, tom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclopia
Cyclopia (named after the Greek mythology character cyclopes) is the most extreme form of holoprosencephaly and is a congenital disorder (birth defect) characterized by the failure of the embryonic prosencephalon to properly divide the orbits of the eye into two cavities. Its incidence is 1 in 16,000 in born animals and 1 in 200 in miscarried fetuses. Signs and symptoms Typically, the nose is either missing or not functional. This deformity (called proboscis) forms above the center eye and is characteristic of a form of cyclopia called rhinencephaly or rhinocephaly. Most such embryos are either naturally aborted or are stillborn upon delivery. Although cyclopia is rare, several cyclopic human babies are preserved in medical museums (e.g. The Vrolik Museum, Amsterdam, Trivandrum Medical College). Some extreme cases of cyclopia have been documented in farm animals (horses, sheep, pigs, and sometimes chickens). In such cases, the nose and mouth fail to form, or the nose grows ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Veratrum Californicum
''Veratrum californicum'' (California corn lily, white or California false hellebore) is an extremely poisonous plant native to western North America, including the Sierra Nevada and Rocky Mountains, as far north as Washington and as far south as Durango; depending on latitude, it grows from near sea level to as high as 11,000 feet. It grows 1 to 2 meters tall, with an erect, unbranched, heavily leafy stem resembling a cornstalk. It prefers quite moist soil, and can cover large areas in dense stands near streams or in wet meadows. Many inch-wide flowers cluster along the often-branched top of the stout stem; they have 6 white tepals, a green center, 6 stamens, and a 3-branched pistil (see image below). The buds are tight green spheres. The heavily veined, bright green leaves can be more than a foot long. ''Veratrum californicum'' displays mast seeding; populations bloom and seed little in most years, but in occasional years bloom and seed heavily in synchrony. The species usually ... [...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] |
Holoprosencephaly Induced By Cyclopamine
Holoprosencephaly (HPE) is a cephalic disorder in which the prosencephalon (the forebrain of the embryo) fails to develop into two hemispheres, typically occurring between the 18th and 28th day of gestation. Normally, the forebrain is formed and the face begins to develop in the fifth and sixth weeks of human pregnancy. The condition also occurs in other species. Holoprosencephaly is estimated to occur in approximately 1 in every 250 conceptions and most cases are not compatible with life and result in fetal death in utero due to deformities to the skull and brain. However, holoprosencephaly is still estimated to occur in approximately 1 in every 8,000 live births. When the embryo's forebrain does not divide to form bilateral cerebral hemispheres (the left and right halves of the brain), it causes defects in the development of the face and in brain structure and function. The severity of holoprosencephaly is highly variable. In less severe cases, babies are born with normal or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sonidegib
Sonidegib (INN), sold under the brand name Odomzo, is a medication used to treat cancer. Sonidegib is Hedgehog signaling pathway inhibitor (via smoothened antagonism). Approvals and indications It was approved for medical use in the United States and in the European Union in 2015 It is indicated for the treatment of adults with locally advanced basal-cell carcinoma that has recurred following surgery or radiation therapy, or those who are not candidates for surgery or radiation therapy. Pharmacology Sonidegib is administered by mouth. Common side effects include muscle spasms, hair loss, fatigue, abdominal pain, nausea, headache, and weight loss. Sonidegib binds to and inhibits smoothened to inhibit activation of the Hedgehog pathway. Sonidegib is primarily metabolized by CYP3A and is eliminated hepatically. Development It has been investigated as a potential treatment for: * Pancreatic cancer * Breast cancer * Basal cell carcinoma of the skin * Small cell lung cancer * Med ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Functional Analog (chemistry)
In chemistry and pharmacology, functional analogs are chemical compounds that have similar physical, chemical, biochemical, or pharmacological properties. Functional analogs are not necessarily structural analogs with a similar chemical structure. An example of pharmacological functional analogs are morphine, heroin and fentanyl, which have the same mechanism of action, but fentanyl is structurally quite different from the other two with significant variance in dosage. File:Morphin - Morphine.svg, Morphine File:Heroin - Heroine.svg, Heroin File:Fentanyl2DCSD.svg, Fentanyl See also *Federal Analogue Act The Federal Analogue Act, , is a section of the United States Controlled Substances Act passed in 1986 which allows any chemical "substantially similar" to a controlled substance listed in Schedule I or II to be treated as if it were listed in ... References Chemical nomenclature Pharmacology {{pharma-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angiogenesis
Angiogenesis is the physiological process through which new blood vessels form from pre-existing vessels, formed in the earlier stage of vasculogenesis. Angiogenesis continues the growth of the vasculature by processes of sprouting and splitting. Vasculogenesis is the embryonic formation of endothelial cells from mesoderm cell precursors, and from neovascularization, although discussions are not always precise (especially in older texts). The first vessels in the developing embryo form through vasculogenesis, after which angiogenesis is responsible for most, if not all, blood vessel growth during development and in disease. Angiogenesis is a normal and vital process in growth and development, as well as in wound healing and in the formation of granulation tissue. However, it is also a fundamental step in the transition of tumors from a benign state to a malignant one, leading to the use of angiogenesis inhibitors in the treatment of cancer. The essential role of angiogenesis in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
