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Tumor Promotion , which promote or cause downstream activation of growth factors and cell survival signals such as RAS, Tumor promotion is a process in carcinogenesis by which various factors permit the descendants of a single initiated cell to survive and expand in number, i.e. to resist apoptosis and to undergo clonal growth. This is a step toward tumor progression. In order for a tumor cell to survive, it must decrease its expression of tumor suppressor genes such as p53, BRCA1, BRCA2, RB1, or the fas receptor. A tumor suppressor would trigger an apoptotic pathway in a cancer cell if there were DNA damage, polyploidy, or uncontrolled cell growth. Simultaneously, tumor cells need to upregulate oncogenes An oncogene is a gene that has the potential to cause cancer. In tumor cells, these genes are often mutated, or expressed at high levels. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carcinogenesis
Carcinogenesis, also called oncogenesis or tumorigenesis, is the formation of a cancer, whereby normal cell (biology), cells are malignant transformation, transformed into cancer cells. The process is characterized by changes at the cellular, Genetics, genetic, and Epigenetics, epigenetic levels and abnormal cell division. Cell division is a physiological process that occurs in almost all Tissue (biology), tissues and under a variety of circumstances. Normally, the balance between proliferation and programmed cell death, in the form of apoptosis, is maintained to ensure the integrity of tissues and Organ (anatomy), organs. According to the prevailing accepted theory of carcinogenesis, the somatic mutation theory, mutations in DNA and Epigenetics, epimutations that lead to cancer disrupt these orderly processes by interfering with the programming regulating the processes, upsetting the normal balance between proliferation and cell death. This results in uncontrolled cell division ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tumor Initiation
Tumor initiation is defined as "a process in which normal cells are changed so that they are able to form tumors". It is the first phase in tumor development. Mutagens, substances that cause cancer can be tumor initiators. See also * Tumor promotion Tumor promotion is a process in carcinogenesis by which various factors permit the descendants of a single initiated cell to survive and expand in number, i.e. to resist apoptosis and to undergo clonal growth. This is a step toward tumor progres ... * Tumor progression References Carcinogenesis {{Oncology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apoptosis
Apoptosis (from ) is a form of programmed cell death that occurs in multicellular organisms and in some eukaryotic, single-celled microorganisms such as yeast. Biochemistry, Biochemical events lead to characteristic cell changes (Morphology (biology), morphology) and death. These changes include Bleb (cell biology), blebbing, Plasmolysis, cell shrinkage, Karyorrhexis, nuclear fragmentation, Pyknosis, chromatin condensation, Apoptotic DNA fragmentation, DNA fragmentation, and mRNA decay. The average adult human loses 50 to 70 1,000,000,000, billion cells each day due to apoptosis. For the average human child between 8 and 14 years old, each day the approximate loss is 20 to 30 billion cells. In contrast to necrosis, which is a form of traumatic cell death that results from acute cellular injury, apoptosis is a highly regulated and controlled process that confers advantages during an organism's life cycle. For example, the separation of fingers and toes in a developing human embryo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clone (cell Biology)
A clone is a group of ''identical'' cells that share a ''common ancestry'', meaning they are derived from the same cell. Clonality implies the state of a cell or a substance being derived from one source or the other. Thus there are terms like ''polyclonal''—derived from many clones; ''oligoclonal''—derived from a few clones; and ''monoclonal''—derived from one clone. These terms are most commonly used in context of antibodies or immunocytes. Contexts This concept of clone assumes importance as all the cells that form a clone share common ancestry, which has a very significant consequence: shared genotype. # One of the most prominent usage is in describing a clone of B cells. The B cells in the body have two important phenotypes (functional forms)—the antibody secreting, terminally differentiated (that is, they cannot divide further) plasma cells, and the memory and the naive cells—both of which retain their proliferative potential. # Another important area where o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tumor Progression
Tumor progression is the third and last phase in tumor development. This phase is characterised by increased growth speed and invasiveness of the tumor cells. As a result of the progression, phenotypical changes occur and the tumor becomes more aggressive and acquires greater malignant potential. Together with the progression, more and more aneuploidy occurs. This may be evident as nuclear polymorphism. See also * Tumor initiation * Tumor promotion Tumor promotion is a process in carcinogenesis by which various factors permit the descendants of a single initiated cell to survive and expand in number, i.e. to resist apoptosis and to undergo clonal growth. This is a step toward tumor progres ... References External links Progressionentry in the public domain NCI Dictionary of Cancer Terms Carcinogenesis {{Oncology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tumor Suppressor Genes
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, and when mutated, can cause ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BRCA1
Breast cancer type 1 susceptibility protein is a protein that in humans is encoded by the ''BRCA1'' () gene. Orthologs are common in other vertebrate species, whereas invertebrate genomes may encode a more distantly related gene. ''BRCA1'' is a human tumor suppressor gene (also known as a caretaker gene) and is responsible for repairing DNA. ''BRCA1'' and ''BRCA2'' are unrelated proteins, but both are normally expressed in the cells of breast and other tissues, where they help repair damaged DNA, or destroy cells if DNA cannot be repaired. They are involved in the repair of chromosomal damage with an important role in the error-free repair of DNA double-strand breaks. If ''BRCA1'' or ''BRCA2'' itself is damaged by a BRCA mutation, damaged DNA is not repaired properly, and this increases the risk for breast cancer. ''BRCA1'' and ''BRCA2'' have been described as "breast cancer susceptibility genes" and "breast cancer susceptibility proteins". The predominant allele has a no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BRCA2
''BRCA2'' and BRCA2 () are human genes and their protein products, respectively. The official symbol (BRCA2, italic for the gene, nonitalic for the protein) and the official name (originally breast cancer 2; currently BRCA2, DNA repair associated) are gene nomenclature, maintained by the HUGO Gene Nomenclature Committee. One alternative symbol, FANCD1, recognizes its association with the FANC proteins, FANC protein complex. Orthologs, styled ''Brca2'' and Brca2, are common in other vertebrate species. May 2021 ''BRCA2'' is a human tumor suppressor gene (specifically, a caretaker gene), found in all humans; its protein, also called by the synonym breast cancer type 2 susceptibility protein, is responsible for repairing DNA. ''BRCA2'' and ''BRCA1'' are normally expressed in the cells of breast and other tissue, where they help repair damaged DNA or destroy cells if DNA cannot be repaired. They are involved in the repair of chromosome, chromosomal damage with an important role in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retinoblastoma Protein
Retinoblastoma (Rb) is a rare form of cancer that rapidly develops from the immature cells of a retina, the light-detecting tissue of the eye. It is the most common primary malignant intraocular cancer in children, and 80% of retinoblastoma cases are first detected in those under 3 years old. Though most children in high income countries survive this cancer, they may lose their vision in the affected eye(s) or need to have the eye removed. Almost half of children with retinoblastoma have a hereditary genetic defect associated with it. In other cases, retinoblastoma is caused by a congenital mutation in the chromosome 13 gene 13q14 ( retinoblastoma protein). Signs and symptoms Retinoblastoma is the most intrusive intraocular cancer among children. The chance of survival and preservation of the eye depends fully on the severity. Retinoblastoma is extremely rare as there are only about 200 to 300 cases every year in the United States. Globally, only 1 in about 15,000 childre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fas Receptor
The Fas receptor, also known as Fas, FasR, apoptosis antigen 1 (APO-1 or APT), cluster of differentiation 95 (CD95) or tumor necrosis factor receptor superfamily member 6 (TNFRSF6), is a protein that in humans is encoded by the ''FAS'' gene. Fas was first identified using a monoclonal antibody generated by immunizing mice with the FS-7 cell line. Thus, the name Fas is derived from ''F''S-7-''a''ssociated ''s''urface antigen. The Fas receptor is a death receptor on the surface of cells that leads to programmed cell death (apoptosis) if it binds its ligand, Fas ligand (FasL). It is one of two apoptosis pathways, the other being the mitochondrial pathway. Gene FAS receptor gene is located on the long arm of chromosome 10 (10q24.1) in humans and on chromosome 19 in mice. The gene lies on the plus ( Watson strand) and is 25,255 bases in length organized into nine protein encoding exons. Similar sequences related by evolution ( orthologs) are found in most mammals. Protein ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oncogenes
An oncogene is a gene that has the potential to cause cancer. In tumor cells, these genes are often mutated, or expressed at high levels.Kimball's Biology Pages. "Oncogenes" Free full text Most normal cells undergo a preprogrammed rapid cell death () if critical functions are altered and then malfunction. Activated oncogenes can cause those cells designated for apoptosis to survive and proliferate instead. Most oncogenes began as proto-oncogenes: normal genes involved in cell growth and proliferation or inhibition of apoptosis. If, through mutation, normal genes promoting cellular growth are up-regulated (gain-of-function mutation), they predispose the cel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mitogen-activated Protein Kinase Kinase
Mitogen-activated protein kinase kinase (also known as MAP2K, MEK, MAPKK) is a dual-specificity kinase enzyme which phosphorylates mitogen-activated protein kinase (MAPK). MAP2K is classified as . There are seven genes: * (a.k.a. MEK1) * (a.k.a. MEK2) * (a.k.a. MKK3) * (a.k.a. MKK4) * (a.k.a. MKK5) * (a.k.a. MKK6) * (a.k.a. MKK7) The activators of p38 (MKK3 and MKK6), JNK (MKK4 and MKK7), and ERK (MEK1 and MEK2) define independent MAP kinase signal transduction pathways. The acronym MEK derives from MAPK/ERK Kinase. Role in melanoma MEK is a member of the MAPK signaling cascade that is activated in melanoma. When MEK is inhibited, cell proliferation is blocked and apoptosis (controlled cell death) is induced. See also * Signal transduction * MAP kinase * MAP kinase kinase kinase Mitogen Activated Protein (MAP) kinase kinase kinase (MAPKKK, MKKK, M3K, or, MAP3K) is a serine/threonine-specific protein kinase which acts upon MAP kinase kinase. Subsequ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
