Oncogene

An oncogene is a gene that can cause a cell to develop into a tumor cell, possibly resulting in cancer.

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A proto-oncogene is a gene which is involved in signal transduction and execution of mitogenic signals, usually through its protein product. Upon activation, it (or its product) becomes a tumor inducing agent, an oncogene.

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Activation

The proto-oncogene can become an oncogene by a relatively small modification of its original function. There are two basic activation types:

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• A mutation within a protooncogene can cause a change in the protein structure, caused by
• an increase in protein (enzyme) activity
• a loss of regulation
• the creation of a hybrid protein, through a chromosomal aberration during cell division. A distinct aberration in a dividing stem cell in the bone marrow leads to adult leukemia
• An increase in protein concentration, caused by
• an increase of protein expression (through misregulation)
• an increase of protein stability, prolonging its existence and thus its activity in the cell
• a gene duplication, resulting in an increased amount of protein in the cell

Gene: :For the band called Gene, see Gene (band)...

Cell: A cell is a single unit or compartment, enclosed by a border or wall. A cell is usually part of a larger structure. More specific meanings depend on the context in which the work is used....

Tumor: See the article about cancer for the main article about malignant tumors....