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Cyclin B
Cyclin B is a member of the cyclin family. Cyclin B is a mitotic cyclin. The amount of cyclin B (which binds to Cdk1) and the activity of the cyclin B-Cdk complex rise through the cell cycle until mitosis, where they fall abruptly due to degradation of cyclin B (Cdk1 is constitutively present). The complex of Cdk and cyclin B is called maturation promoting factor or mitosis promoting factor (MPF). Function Cyclin B is necessary for the progression of the cells into and out of M phase of the cell cycle. At the end of S phase the phosphatase cdc25c dephosphorylates tyrosine15 and this activates the cyclin B/CDK1 complex. Upon activation the complex is shuttled to the nucleus where it serves to trigger for entry into mitosis. However, if DNA damage is detected alternative proteins are activated which results in the inhibitory phosphorylation of cdc25c and therefore cyclinB/CDK1 is not activated. In order for the cell to progress out of mitosis, the degradation of cyclin B i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclin B1
G2/mitotic-specific cyclin-B1 is a protein that in humans is encoded by the ''CCNB1'' gene. Function Cyclin B1 is a regulatory protein involved in mitosis. The gene product complexes with p34 (Cdk1) to form the maturation-promoting factor (MPF). Two alternative transcripts have been found, a constitutively expressed transcript and a cell cycle-regulated transcript that is expressed predominantly during G2/M phase of the cell cycle. The different transcripts result from the use of alternate transcription initiation sites. Cyclin B1 contributes to the switch-like all or none behavior of the cell in deciding to commit to mitosis. Its activation is well-regulated, and positive feedback loops ensure that once the cyclin B1-Cdk1 complex is activated, it is not deactivated. Cyclin B1-Cdk1 is involved in the early events of mitosis, such as chromosome condensation, nuclear envelope breakdown, and spindle pole assembly. Once activated, cyclin B1-Cdk1 promotes several of the events of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biopsies
A biopsy is a medical test commonly performed by a surgeon, an interventional radiologist, or an interventional cardiologist. The process involves the extraction of sample cells or tissues for examination to determine the presence or extent of a disease. The tissue is then fixed, dehydrated, embedded, sectioned, stained and mounted before it is generally examined under a microscope by a pathologist; it may also be analyzed chemically. When an entire lump or suspicious area is removed, the procedure is called an excisional biopsy. An incisional biopsy or core biopsy samples a portion of the abnormal tissue without attempting to remove the entire lesion or tumor. When a sample of tissue or fluid is removed with a needle in such a way that cells are removed without preserving the histological architecture of the tissue cells, the procedure is called a needle aspiration biopsy. Biopsies are most commonly performed for insight into possible cancerous or inflammatory conditions. Hist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Cycle Regulators
Cell most often refers to: * Cell (biology), the functional basic unit of life * Cellphone, a phone connected to a cellular network * Clandestine cell, a penetration-resistant form of a secret or outlawed organization * Electrochemical cell, a device used to convert chemical energy to electrical energy * Prison cell, a room used to hold people in prisons Cell may also refer to: Arts, entertainment, and media Fictional entities * Cell (comics), a Marvel comic book character * Cell (''Dragon Ball''), a character in the manga series ''Dragon Ball'' Literature * ''Cell'' (novel), a 2006 horror novel by Stephen King * "Cells", poem, about a hungover soldier in gaol, by Rudyard Kipling * ''The Cell'' (play), an Australian play by Robert Wales Music * Cell (music), a small rhythmic and melodic design that can be isolated, or can make up one part of a thematic context * Cell (American band) * Cell (Japanese band) * ''Cell'' (album), a 2004 album by Plastic Tree * ''Cells'', a 1998 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tumor Markers
A tumor marker is a Biomarker (medicine), biomarker that can be used to indicate the presence of cancer or the behavior of cancers (measure progression or response to therapy). They can be found in Body fluid, bodily fluids or Tissue (biology), tissue. Markers can help with assessing prognosis, surveilling patients after surgical removal of tumors, and even predicting drug-response and monitor therapy. Tumor markers can be molecules that are produced in higher amounts by cancer cells than normal cells, but can also be produced by other cells from a reaction with the cancer. The markers can't be used to give patients a diagnosis but can be compared with the result of other tests like biopsy or imaging. Classification Tumor markers can be proteins, carbohydrates, receptors and gene products. Proteins include hormones and enzymes. To detect enzyme tumor markers enzyme activity is measured. They were previously widely used, but they have largely been replaced by oncofetal antigens ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biomarkers
In biomedical contexts, a biomarker, or biological marker, is a measurable indicator of some biological state or condition. Biomarkers are often measured and evaluated using blood, urine, or soft tissues to examine normal biological processes, pathogenic processes, or pharmacologic responses to a therapeutic intervention. as cited in Biomarkers are used in many scientific fields. Medicine Biomarkers used in the medical field, are a part of a relatively new clinical toolset categorized by their clinical applications. The four main classes are molecular, physiologic, histologic and radiographic biomarkers. All four types of biomarkers have a clinical role in narrowing or guiding treatment decisions and follow a sub-categorization of being either predictive, prognostic, or diagnostic. Predictive Predictive molecular, cellular, or imaging biomarkers that pass validation can serve as a method of predicting clinical outcomes. Predictive biomarkers are used to help optimize ide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclin B2
G2/mitotic-specific cyclin-B2 is a protein that in humans is encoded by the ''CCNB2'' gene. Function Cyclin B2 is a member of the cyclin family, specifically the B-type cyclins. The B-type cyclins, B1 and B2, associate with p34cdc2 and are essential components of the cell cycle regulatory machinery. B1 and B2 differ in their subcellular localization. Cyclin B1 co-localizes with microtubules, whereas cyclin B2 is primarily associated with the Golgi region. Cyclin B2 also binds to transforming growth factor beta RII and thus cyclin B2/cdc2 may play a key role in transforming growth factor beta-mediated cell cycle control. Interactions Cyclin B2 has been shown to interact with TGF beta receptor 2 Transforming growth factor, beta receptor II (70/80kDa) is a TGF beta receptor. ''TGFBR2'' is its human gene. It is a tumor suppressor gene. Function This gene encodes a member of the serine/threonine protein kinase family and the TGFB recep .... See also * Cyclin B Refe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclin B1
G2/mitotic-specific cyclin-B1 is a protein that in humans is encoded by the ''CCNB1'' gene. Function Cyclin B1 is a regulatory protein involved in mitosis. The gene product complexes with p34 (Cdk1) to form the maturation-promoting factor (MPF). Two alternative transcripts have been found, a constitutively expressed transcript and a cell cycle-regulated transcript that is expressed predominantly during G2/M phase of the cell cycle. The different transcripts result from the use of alternate transcription initiation sites. Cyclin B1 contributes to the switch-like all or none behavior of the cell in deciding to commit to mitosis. Its activation is well-regulated, and positive feedback loops ensure that once the cyclin B1-Cdk1 complex is activated, it is not deactivated. Cyclin B1-Cdk1 is involved in the early events of mitosis, such as chromosome condensation, nuclear envelope breakdown, and spindle pole assembly. Once activated, cyclin B1-Cdk1 promotes several of the events of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SiRNA
Small interfering RNA (siRNA), sometimes known as short interfering RNA or silencing RNA, is a class of double-stranded non-coding RNA molecules, typically 20–24 base pairs in length, similar to microRNA (miRNA), and operating within the RNA interference (RNAi) pathway. It interferes with the expression of specific genes with complementary nucleotide sequences by degrading messenger RNA (mRNA) after transcription, preventing translation. Text was copied from this source, which is available under Creative Commons Attribution 4.0 International License It was discovered in 1998 by Andrew Fire at the Carnegie Institution for Science in Washington, D.C. and Craig Mello at the University of Massachusetts in Worcester. Structure Naturally occurring siRNAs have a well-defined structure that is a short (usually 20 to 24- bp) double-stranded RNA (dsRNA) with phosphorylated 5' ends and hydroxylated 3' ends with two overhanging nucleotides. The Dicer enzyme catalyzes prod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WAF1
p21Cip1 (alternatively p21Waf1), also known as cyclin-dependent kinase inhibitor 1 or CDK-interacting protein 1, is a cyclin-dependent kinase inhibitor (CKI) that is capable of inhibiting all cyclin/ CDK complexes, though is primarily associated with inhibition of CDK2. p21 represents a major target of p53 activity and thus is associated with linking DNA damage to cell cycle arrest.Waldman, Todd, Kenneth W. Kinzler, and Bert Vogelstein. "p21 is necessary for the p53-mediated G1 arrest in human cancer cells." Cancer research 55.22 (1995): 5187-5190. This protein is encoded by the ''CDKN1A'' gene located on chromosome 6 (6p21.2) in humans. Function CDK inhibition p21 is a potent cyclin-dependent kinase inhibitor (CKI). The p21 (CIP1/WAF1) protein binds to and inhibits the activity of cyclin-CDK2, -CDK1, and -CDK4 /6 complexes, and thus functions as a regulator of cell cycle progression at G1 and S phase. The binding of p21 to CDK complexes occurs through p21's N-terminal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Cycle Checkpoint
Cell cycle checkpoints are control mechanisms in the eukaryotic cell cycle which ensure its proper progression. Each checkpoint serves as a potential termination point along the cell cycle, during which the conditions of the cell are assessed, with progression through the various phases of the cell cycle occurring only when favorable conditions are met. There are many checkpoints in the cell cycle, but the three major ones are: the G1 checkpoint, also known as the Start or restriction checkpoint or Major Checkpoint; the G2/M checkpoint; and the metaphase-to-anaphase transition, also known as the spindle checkpoint. Progression through these checkpoints is largely determined by the activation of cyclin-dependent kinases by regulatory protein subunits called cyclins, different forms of which are produced at each stage of the cell cycle to control the specific events that occur therein. Background All living organisms are the products of repeated rounds of cell growth and division. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastric Cancer
Stomach cancer, also known as gastric cancer, is a malignant tumor of the stomach. It is a cancer that develops in the lining of the stomach. Most cases of stomach cancers are gastric carcinomas, which can be divided into a number of subtypes, including gastric adenocarcinomas. Lymphomas and mesenchymal tumors may also develop in the stomach. Early symptoms may include heartburn, upper abdominal pain, nausea, and loss of appetite. Later signs and symptoms may include weight loss, yellowing of the skin and whites of the eyes, vomiting, difficulty swallowing, and blood in the stool, among others. The cancer may spread from the stomach to other parts of the body, particularly the liver, lungs, bones, lining of the abdomen, and lymph nodes. The bacterium ''Helicobacter pylori'' accounts for more than 60% of cases of stomach cancer. Certain strains of ''H. pylori'' have greater risks than others. Smoking, dietary factors such as pickled vegetables and obesity are other ris ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biomarker
In biomedical contexts, a biomarker, or biological marker, is a measurable indicator of some biological state or condition. Biomarkers are often measured and evaluated using blood, urine, or soft tissues to examine normal biological processes, pathogenic processes, or pharmacologic responses to a therapeutic intervention. as cited in Biomarkers are used in many scientific fields. Medicine Biomarkers used in the medical field, are a part of a relatively new clinical toolset categorized by their clinical applications. The four main classes are molecular, physiologic, histologic and radiographic biomarkers. All four types of biomarkers have a clinical role in narrowing or guiding treatment decisions and follow a sub-categorization of being either predictive, prognostic, or diagnostic. Predictive Predictive molecular, cellular, or imaging biomarkers that pass validation can serve as a method of predicting clinical outcomes. Predictive biomarkers are used to help optimize ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
