Navigation Links

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



A protooncogene is a gene that 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.


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

  • A mutation within a protooncogene can cause a change in the protein structure, caused by
  • 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 a doubled amount of protein in the cell


Growth factors

Growth factors are usually secreted by a few special cells to induce cell proliferation in other cells. If a cell that usually does not produce growth factors suddenly starts to do so (because it developed an oncogene), it will thereby induce its own uncontrolled proliferation (autocrine loop ), as well as the proliferation of neighboring cells.

Protein kinases and related proteins

There are six known classes of protein kinases and related proteins that can become an oncogene:

  1. Receptor tyrosine kinases that become constitutive (permanently) active like the epidermal growth factor receptor (EGFR), platelet-derived growth factor receptor (PDGFR), vascular endothelial growth factor receptor (VEGFR), etc.
  2. Cytoplasmic tyrosine kinases like the Src-family, Syk-ZAP-70 family and BTK family of tyrosine kinases.
  3. Regulatory GTPases, for example, the Ras protein.
  4. Cytoplasmic Serine/Threonine kinases and their regulatory subunits, for example, the Raf kinase , and cyclin-dependent kinases (through overexpression).
  5. Adaptor proteins in signal transduction.
  6. Transcription factors.

Related articles


(Date:8/19/2014)... German . , , ... of plants can switch off individual genes and study ... Planck Institute for Plant Breeding Research in Cologne and ... different approach. They identify small molecules that block specific ... prevent the downstream reactions. In their search for these ...
(Date:8/19/2014)... young have bigger brains than counterparts that don,t care ... study. , Stickleback fish are well known in the ... the species, rather than the female, cares for offspring. ... researchers wanted to find out if the difference in ... , In the study, published recently in Ecology ...
(Date:8/18/2014)... Ariz. Half of the Earth,s land mass is ... yet they are being transformed at an alarming rate. ... in and taking over, leading to a loss of ... ability of ecosystems to produce food specifically meat. ... Life Sciences led an investigation that quantified this loss ...
Breaking Biology News(10 mins):Researchers block plant hormone 2Researchers block plant hormone 3Trees and shrubs invading critical grasslands, diminish cattle production 2Trees and shrubs invading critical grasslands, diminish cattle production 3
... N.Y. Proteins are critically important to life and the ... in nature, and there is much we still don,t know ... the stability of enzymes, a particular type of protein that ... natural environment in the cell or body, enzymes can quickly ...
... that nanoparticles, which are now present in everything from ... irreparably damaging effects on soil systems and the environment. ... every year, including silver nanoparticles which are popular as ... Department of Biology. "We started to wonder what the ...
... (April 6, 2011) -- A new drug delivery device ... Peter Rentzepis promises to unlock the potential of photosensitive ... as well. Photosensitive chemicals are molecules that ... These radicals are very active chemically, and can rip ...
Cached Biology News:Nano fit-ness: Helping enzymes stay active and keep in shape 2Common nanoparticles found to be highly toxic to Arctic ecosystem 2New device promises safer way to deliver powerful drugs 2
Other biology definitionOther Tags