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Oncogene
OncogeneAn oncogene is a special type of gene that is capable of transforming host cells and triggering carcinogenesis. The name is derived from the Greek onkos, meaning bulk, or mass, because of the ability to cause tumor growth. Oncogenes were first discovered in retroviruses (viruses containing the enzyme reverse transcriptase, and RNA , rather than DNA ) that were found to cause cancer in many animals (e.g., feline leukemia virus, simian sarcoma virus). Although this is a relatively common mechanism of oncogenesis in animals, very few oncogene-carrying viruses have been identified in man. The ones that are known include the papilloma virus HPV16 that is associated with cervical cancer, HTLV-1 and HTLV-2 associated with T-cell leukemia, and HIV-1 associated with Kaposi sarcoma. Studies of humans led to the discovery of related genes called proto-oncogenes that exist naturally in the human genome. These genes have DNA sequences that are similar to oncogenes, but under normal conditions, the proto-oncogenes do not cause cancer. However, specific mutations in these genes can transform them to an oncogenic form that may lead to carcinogenesis. So, in humans, there are two unique ways in which oncogenesis occurs, by true viral infection and by mutation of proto-oncogenes that already exist in human cells. See also Molecular biology and molecular genetics; Oncogenetic research; Viral genetics; Viral vectors in gene therapy; Virology; Virus replication; Viruses and responses to viral infection |
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"Oncogene." World of Microbiology and Immunology. 2003. Encyclopedia.com. 29 May. 2012 <http://www.encyclopedia.com>. "Oncogene." World of Microbiology and Immunology. 2003. Encyclopedia.com. (May 29, 2012). http://www.encyclopedia.com/doc/1G2-3409800416.html "Oncogene." World of Microbiology and Immunology. 2003. Retrieved May 29, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1G2-3409800416.html |
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oncogene
oncogene A dominant mutant allele of a cellular gene (a proto-oncogene) that disrupts cell growth and division and is capable of transforming a normal cell into a cancerous cell. Proto-oncogenes typically encode proteins involved in positive control of the cell division cycle, such as growth factor receptors, signal transduction proteins, and transcription factors. Mutations in these genes tend to relax control mechanisms and accelerate cell division, leading to the cell proliferation that is characteristic of cancer. Some oncogenic mutations cause inhibition of programmed cell death (apoptosis), so that cancerous cells are less likely to be destroyed by the body's defences. Certain oncogenes of vertebrates are derived from viruses (see oncogenic). Compare tumour-suppressor gene.
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"oncogene." A Dictionary of Biology. 2004. Encyclopedia.com. 29 May. 2012 <http://www.encyclopedia.com>. "oncogene." A Dictionary of Biology. 2004. Encyclopedia.com. (May 29, 2012). http://www.encyclopedia.com/doc/1O6-oncogene.html "oncogene." A Dictionary of Biology. 2004. Retrieved May 29, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O6-oncogene.html |
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oncogenic
oncogenic Describing a chemical, organism, or environmental factor that causes the development of cancer. Some viruses are oncogenic to vertebrates, notably the retroviruses (including the Rous sarcoma virus of chickens), and some are suspected of being oncogenic (e.g. some of the adenoviruses and papovaviruses). Many of these viruses contain genes (known as oncogenes) that are responsible for the transformation of a normal host cell into a cancerous cell. See also growth factor.
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"oncogenic." A Dictionary of Biology. 2004. Encyclopedia.com. 29 May. 2012 <http://www.encyclopedia.com>. "oncogenic." A Dictionary of Biology. 2004. Encyclopedia.com. (May 29, 2012). http://www.encyclopedia.com/doc/1O6-oncogenic.html "oncogenic." A Dictionary of Biology. 2004. Retrieved May 29, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O6-oncogenic.html |
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oncogene
oncogene (onk-oh-jeen) n. a gene in viruses and mammalian cells that can cause cancer; it results from the mutation of a normal gene and is capable of both initiation and continuation of malignant transformation of normal cells. Oncogenes probably produce peptides (growth factors) regulating cell division that, under certain conditions, become uncontrolled and may transform a normal cell to a malignant state.
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"oncogene." A Dictionary of Nursing. 2008. Encyclopedia.com. 29 May. 2012 <http://www.encyclopedia.com>. "oncogene." A Dictionary of Nursing. 2008. Encyclopedia.com. (May 29, 2012). http://www.encyclopedia.com/doc/1O62-oncogene.html "oncogene." A Dictionary of Nursing. 2008. Retrieved May 29, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O62-oncogene.html |
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oncogene
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"oncogene." World Encyclopedia. 2005. Encyclopedia.com. 29 May. 2012 <http://www.encyclopedia.com>. "oncogene." World Encyclopedia. 2005. Encyclopedia.com. (May 29, 2012). http://www.encyclopedia.com/doc/1O142-oncogene.html "oncogene." World Encyclopedia. 2005. Retrieved May 29, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O142-oncogene.html |
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oncogenic
oncogenic (onk-oh-jen-ik) adj. describing a substance, organism, or environment that is known to be a causal factor in the production of a tumour. Some viruses are oncogenic. See also carcinogen.
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"oncogenic." A Dictionary of Nursing. 2008. Encyclopedia.com. 29 May. 2012 <http://www.encyclopedia.com>. "oncogenic." A Dictionary of Nursing. 2008. Encyclopedia.com. (May 29, 2012). http://www.encyclopedia.com/doc/1O62-oncogenic.html "oncogenic." A Dictionary of Nursing. 2008. Retrieved May 29, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O62-oncogenic.html |
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oncogene
on·co·gene / ˈängkəˌjēn/ • n. Med. a gene that in certain circumstances can transform a cell into a tumor cell. |
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"oncogene." The Oxford Pocket Dictionary of Current English. 2009. Encyclopedia.com. 29 May. 2012 <http://www.encyclopedia.com>. "oncogene." The Oxford Pocket Dictionary of Current English. 2009. Encyclopedia.com. (May 29, 2012). http://www.encyclopedia.com/doc/1O999-oncogene.html "oncogene." The Oxford Pocket Dictionary of Current English. 2009. Retrieved May 29, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O999-oncogene.html |
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oncogene
oncogene A gene that has the ability to cause eukaryotic cells to grow in an unregulated fashion, like that of a cancerous tumour. compare APOPTOSIS.
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MICHAEL ALLABY. "oncogene." A Dictionary of Zoology. 1999. Encyclopedia.com. 29 May. 2012 <http://www.encyclopedia.com>. MICHAEL ALLABY. "oncogene." A Dictionary of Zoology. 1999. Encyclopedia.com. (May 29, 2012). http://www.encyclopedia.com/doc/1O8-oncogene.html MICHAEL ALLABY. "oncogene." A Dictionary of Zoology. 1999. Retrieved May 29, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O8-oncogene.html |
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oncogenic
oncogenic Capable of causing the formation of tumours.
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MICHAEL ALLABY. "oncogenic." A Dictionary of Ecology. 2004. Encyclopedia.com. 29 May. 2012 <http://www.encyclopedia.com>. MICHAEL ALLABY. "oncogenic." A Dictionary of Ecology. 2004. Encyclopedia.com. (May 29, 2012). http://www.encyclopedia.com/doc/1O14-oncogenic.html MICHAEL ALLABY. "oncogenic." A Dictionary of Ecology. 2004. Retrieved May 29, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O14-oncogenic.html |
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oncogenic
oncogenic Capable of causing the formation of tumours.
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Cite this article
MICHAEL ALLABY. "oncogenic." A Dictionary of Zoology. 1999. Encyclopedia.com. 29 May. 2012 <http://www.encyclopedia.com>. MICHAEL ALLABY. "oncogenic." A Dictionary of Zoology. 1999. Encyclopedia.com. (May 29, 2012). http://www.encyclopedia.com/doc/1O8-oncogenic.html MICHAEL ALLABY. "oncogenic." A Dictionary of Zoology. 1999. Retrieved May 29, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O8-oncogenic.html |
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