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PTCH1
Protein patched homolog 1 is a protein that is the member of the patched family and in humans is encoded by the ''PTCH1'' gene. Function PTCH1 is a member of the patched gene family and is the receptor for sonic hedgehog, a secreted molecule implicated in the formation of embryonic structures and in tumorigenesis. This gene functions as a tumor suppressor. The PTCH1 gene product, is a transmembrane protein that suppresses the release of another protein called smoothened, and when sonic hedgehog binds PTCH1, smoothened is released and signals cell proliferation. Clinical significance Mutations of this gene have been associated with nevoid basal cell carcinoma syndrome (AKA Gorlin's Syndrome), esophageal squamous cell carcinoma, trichoepitheliomas, transitional cell carcinomas of the bladder, as well as holoprosencephaly. Alternative splicing results in multiple transcript variants encoding different isoforms. Additional splice variants have been described, but their full leng ... [...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] |
Tumor Suppressor
A tumor suppressor gene (TSG), or anti-oncogene, is a gene that regulates a cell during cell division and replication. If the cell grows uncontrollably, it will result in cancer. When a tumor suppressor gene is mutated, it results in a loss or reduction in its function. In combination with other genetic mutations, this could allow the cell to grow abnormally. The loss of function for these genes may be even more significant in the development of human cancers, compared to the activation of oncogenes. TSGs can be grouped into the following categories: caretaker genes, gatekeeper genes, and more recently landscaper genes. Caretaker genes ensure stability of the genome via DNA repair and subsequently when mutated allow mutations to accumulate. Meanwhile, gatekeeper genes directly regulate cell growth by either inhibiting cell cycle progression or inducing apoptosis. Lastly landscaper genes regulate growth by contributing to the surrounding environment, when mutated can cause an envir ... [...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] |
Protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, providing structure to cells and organisms, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific 3D structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called peptides. The individual amino acid residues are bonded together by peptide bonds and adjacent amino acid residues. The sequence of amino acid residue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a basic unit of heredity and the molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protein-coding genes and noncoding genes. During gene expression, the DNA is first copied into RNA. The RNA can be directly functional or be the intermediate template for a protein that performs a function. The transmission of genes to an organism's offspring is the basis of the inheritance of phenotypic traits. These genes make up different DNA sequences called genotypes. Genotypes along with environmental and developmental factors determine what the phenotypes will be. Most biological traits are under the influence of polygenes (many different genes) as well as gen ... [...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] |
Transmembrane Protein
A transmembrane protein (TP) is a type of integral membrane protein that spans the entirety of the cell membrane. Many transmembrane proteins function as gateways to permit the transport of specific substances across the membrane. They frequently undergo significant conformational changes to move a substance through the membrane. They are usually highly hydrophobic and aggregate and precipitate in water. They require detergents or nonpolar solvents for extraction, although some of them (beta-barrels) can be also extracted using denaturing agents. The peptide sequence that spans the membrane, or the transmembrane segment, is largely hydrophobic and can be visualized using the hydropathy plot. Depending on the number of transmembrane segments, transmembrane proteins can be classified as single-span (or bitopic) or multi-span (polytopic). Some other integral membrane proteins are called monotopic, meaning that they are also permanently attached to the membrane, but do not pass ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Squamous Cell Carcinoma
Squamous-cell carcinomas (SCCs), also known as epidermoid carcinomas, comprise a number of different types of cancer that begin in squamous cells. These cells form on the surface of the skin, on the lining of hollow organs in the body, and on the lining of the respiratory and digestive tracts. Common types include: * Squamous-cell skin cancer: A type of skin cancer * Squamous-cell carcinoma of the lung: A type of lung cancer * Squamous-cell thyroid carcinoma: A type of thyroid cancer * Esophageal squamous-cell carcinoma: A type of esophageal cancer * Squamous-cell carcinoma of the vagina: A type of vaginal cancer Despite sharing the name "squamous-cell carcinoma", the SCCs of different body sites can show differences in their presented symptoms, natural history, prognosis, and response to treatment. By body location Human papillomavirus infection has been associated with SCCs of the oropharynx, lung, fingers, and anogenital region. Head and neck cancer About 90% of cases ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trichoepithelioma
Trichoepithelioma is a neoplasm of the adnexa of the skin. Its appearance is similar to basal cell carcinoma. One form has been mapped to chromosome 9p21. Types Trichoepitheliomas may be divided into the following types: :* Multiple familial trichoepithelioma :* Solitary trichoepithelioma :* Desmoplastic trichoepithelioma Pathology Trichoepitheliomas consists of nests of basaloid cells, with palisading. They lack the myxoid stroma and artefactual clefting seen in basal cell carcinoma. Mitoses are uncommon when compared to basal cell carcinoma. Diagnosis Trichoepiteliomas often contain Merkel cells; an immunostain for CK20 can be used to demonstrate this. See also * Trichoblastoma * Pilomatricoma * CYLD cutaneous syndrome * List of cutaneous conditions * List of cutaneous neoplasms associated with systemic syndromes Many cutaneous neoplasms occur in the setting of systemic syndromes. See also *List of cutaneous conditions *List of contact allergens *List of cut ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transitional Cell Carcinoma
Transitional cell carcinoma, also called urothelial carcinoma, is a type of cancer that typically occurs in the urinary system. It is the most common type of bladder cancer and cancer of the ureter, urethra, and urachus. It accounts for 95% of bladder cancer cases. It is the second most common type of kidney cancer, but accounts for only five to 10 percent of all primary renal malignant tumors. Transitional cell carcinomas arise from the transitional epithelium, a tissue lining the inner surface of these hollow organs. When the term "urothelial" is used, it specifically refers to a carcinoma of the urothelium, meaning a transitional cell carcinomas of the urinary system. Signs and symptoms Signs and symptoms of transitional cell carcinomas depend on the location and extent of the cancer. Causes Urothelial carcinoma is a prototypical example of a malignancy arising from environmental carcinogenic influences. By far the most important cause is cigarette smoking, which contribu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holoprosencephaly
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] |
