tumor suppressor gene

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gene

 [jēn]
one of the biologic units of heredity, self-reproducing, and located at a definite position (locus) on a particular chromosome. Genes make up segments of the complex deoxyribonucleic acid (DNA) molecule that controls cellular reproduction and function. There are thousands of genes in the chromosomes of each cell nucleus; they play an important role in heredity because they control the individual physical, biochemical, and physiologic traits inherited by offspring from their parents. Through the genetic code of DNA they also control the day-to-day functions and reproduction of all cells in the body. For example, the genes control the synthesis of structural proteins and also the enzymes that regulate various chemical reactions that take place in a cell.

The gene is capable of replication. When a cell multiplies by mitosis each daughter cell carries a set of genes that is an exact replica of that of the parent cell. This characteristic of replication explains how genes can carry hereditary traits through successive generations without change.
allelic gene allele.
complementary g's two independent pairs of nonallelic genes, neither of which will produce its effect in the absence of the other.
DCC gene (deleted in colorectal carcinoma) a gene normally expressed in the mucosa of the colon but reduced or absent in a small proportion of patients with colorectal cancer.
dominant gene one that produces an effect (the phenotype) in the organism regardless of the state of the corresponding allele. An example of a trait determined by a dominant gene is brown eye color. See also heredity.
histocompatibility gene one that determines the specificity of tissue antigenicity (hla antigens) and thus the compatibility of donor and recipient in tissue transplantation and blood transfusion.
holandric g's genes located on the Y chromosome and appearing only in male offspring.
immune response (Ir) g's genes of the major histocompatibility complex that govern the immune response to individual immunogens.
immune suppressor (Is) g's genes that govern the formation of suppressor T lymphocytes.
immunoglobulin g's the genes coding for immunoglobulin heavy and light chains, which are organized in three loci coding for κ light chains, λ light chains, and heavy chains.
K-ras gene a type of oncogene.
lethal gene one whose presence brings about the death of the organism or permits survival only under certain conditions.
major gene a gene whose effect on the phenotype is always evident, regardless of how this effect is modified by other genes.
mutant gene one that has undergone a detectable mutation.
operator gene one serving as a starting point for reading the genetic code, and which, through interaction with a repressor, controls the activity of structural genes associated with it in the operon.
gene pool all of the genes possessed by all of the members of a population that will reproduce.
recessive gene one that produces an effect in the organism only when it is transmitted by both parents, i.e., only when the individual is homozygous. See also heredity.
regulator gene (repressor gene) one that synthesizes repressor, a substance which, through interaction with the operator gene, switches off the activity of the structural genes associated with it in the operon.
sex-linked gene a gene carried on a sex chromosome (X or Y); only X linkage has clinical significance. See X-linked gene.
structural gene one that forms templates for messenger RNA and is thereby responsible for the amino acid sequence of specific polypeptides.
tumor suppressor gene a gene whose function is to limit cell proliferation and loss of whose function leads to cell transformation and tumor growth; called also antioncogene.
X-linked gene a gene carried on the X chromosome; the corresponding trait, whether dominant or recessive, is always expressed in males, who have only one X chromosome. the term “X-linked” is sometimes used synonymously with “sex-linked,” since no genetic disorders have as yet been associated with genes on the Y chromosome.

tumor suppressor gene

a gene that encodes a protein involved in controlling cellular growth; inactivation of this type of gene leads to deregulated cellular proliferation, as in cancer.
See also: oncogene.
Synonym(s): antioncogene

In a person born with two normal copies of a tumor suppressor gene, both copies must be inactivated by spontaneous point mutation, deletion, or failure of expression before tumor formation occurs. An inherited mutation in a tumor suppressor gene is the basis of most familial predispositions to cancer. In a person so predisposed, malignant cellular proliferation does not occur until the remaining intact copy of the gene is inactivated by deletion of part or all of its chromosome. Of many tumor suppressor genes thus far identified, the p53 gene on chromosome 17, which encodes a phosphoprotein that suppresses cell proliferation, appears to be the most important. Mutations of p53 have been found in the DNA of more than half of all human cancers studied. Li-Fraumeni syndrome, characterized by early-onset carcinomas and sarcomas, is an inherited (autosomal dominant) mutation in the p53 tumor suppressor gene. BRCA1 and BRCA2, involved in familial early-onset breast cancer as well as ovarian and other cancers in people of both sexes, are tumor suppressor genes.

tumor suppressor gene

n.
Any of various genes that normally suppress cellular proliferation and that, when mutated, are associated with the development of certain cancers, including many familial cancers. Also called antioncogene.

tumor suppressor gene

a gene whose function is to limit cell proliferation and loss of whose function leads to cell transformation and tumor growth. Also called antioncogene.

tu·mor sup·pres·sor gene

(tū'mŏr sŭ-pres'ŏr jēn)
1. A gene the function of which is to suppress cellular proliferation. Also known as an antioncogene because it suppresses neoplastic transformation. Loss of a tumor suppressor gene through chromosomal aberration leads to heightened susceptibility to neoplasia.
2. Synonym(s): antioncogene. Synonym(s): tumour supressor gene.

tu·mor sup·pres·sor gene

(tū'mŏr sŭ-pres'ŏr jēn)
Gene that encodes a protein involved in controlling cellular growth.
Synonym(s): tumour suppressor gene.
References in periodicals archive ?
When researchers checked to see if any of the CYCLOPS genes were neighbors of missing tumor suppressor genes, as Frei had hypothesized two decades earlier, they found that, indeed, many were.
Nicotine-derived nitrosamine ketone (NNK) was originally considered only to lead to genetic mutation, but the research study further revealed how NNK would induce epigenetic alteration in the process of cancer formation, inhibiting the tumor suppressor genes and leading to lung cancer.
The particular gene the researchers were studying was p16, a so-called tumor suppressor gene.
Being able to deliver cancer-specific tumor suppressor genes, such as FUS1 and p53, may provide new therapeutic options for cancer patients.
Hypermethylation of tumor suppressor genes is common in many cancers, and has been particularly associated with the clinical progression from MDS to AML.
The tumor suppressor genes we have identified may also be important in preventing the development of multiple types of human cancers since similar abnormalities have been found in renal, breast, head and neck, ovarian, and cervical cancers.
Li and Cohen's gene discovery strategy may have many uses beyond finding tumor suppressor genes.
His research on tumor suppressor genes has not only advanced our understanding of cancer, but it also has provided valuable insight in the role that hereditary predisposition plays into developing cancer," said Dr.
AUSTIN, Texas -- Two powerful tumor suppressor genes, p53 and FUS1, administered intravenously in nanoparticle formulations were capable of significantly shrinking metastatic tumors in models of human lung cancer, according to investigators at The University of Texas M.
In the study entitled "Successful Treatment of Primary and Disseminated Human Lung Cancers by Systemic Delivery of Tumor Suppressor Genes Using an Improved Liposome Vector" conducted at the M.
First they found oncogenes, which stimulate tumor development, then tumor suppressor genes, so named because they normally keep uncontrolled cell growth in check.
In fact, LOH analysis played a key role in the original discovery of tumor suppressor genes (TSGs), whose functional loss is associated with tumor initiation.