Home | Sources Directory | News Releases | Calendar | Articles | | Contact |  

Growth factor

A growth factor is a naturally occurring substance capable of stimulating cellular growth,[1] proliferation and cellular differentiation. Usually it is a protein or a steroid hormone. Growth factors are important for regulating a variety of cellular processes.

Growth factors typically act as signaling molecules between cells. Examples are cytokines and hormones that bind to specific receptors on the surface of their target cells.

They often promote cell differentiation and maturation, which varies between growth factors. For example, bone morphogenic proteins stimulate bone cell differentiation, while fibroblast growth factors and vascular endothelial growth factors stimulate blood vessel differentiation (angiogenesis).

Contents

[edit] Growth factors versus cytokines

Growth factor is sometimes used interchangeably among scientists with the term cytokine. Historically, cytokines were associated with hematopoietic (blood forming) cells and immune system cells (e.g., lymphocytes and tissue cells from spleen, thymus, and lymph nodes). For the circulatory system and bone marrow in which cells can occur in a liquid suspension and not bound up in solid tissue, it makes sense for them to communicate by soluble, circulating protein molecules. However, as different lines of research converged, it became clear that some of the same signaling proteins the hematopoietic and immune systems used were also being used by all sorts of other cells and tissues, during development and in the mature organism.

While growth factor implies a positive effect on cell division, cytokine is a neutral term with respect to whether a molecule affects proliferation. While some cytokines can be growth factors, such as G-CSF and GM-CSF, others have an inhibitory effect on cell growth or proliferation. Some cytokines, such as Fas ligand are used as "death" signals; they cause target cells to undergo programmed cell death or apoptosis.

[edit] Classes of growth factors

Individual growth factor proteins tend to occur as members of larger families of structurally and evolutionarily related proteins. There are many families which are listed below:


Stimulates cell cycle from G0 phase to G1 phase

[edit] Uses in medicine

For the last two decades, growth factors have been increasingly used in the treatment of hematologic and oncologic diseases and cardiovascular diseases like:

[edit] See also

[edit] References

[edit] External links



Related Articles & Resources

Sources Subject Index - Experts, Sources, Spokespersons

Sources Select Resources Articles







This article is based on one or more articles in Wikipedia, with modifications and additional content by SOURCES editors. This article is covered by a Creative Commons Attribution-Sharealike 3.0 License (CC-BY-SA) and the GNU Free Documentation License (GFDL). The remainder of the content of this website, except where otherwise indicated, is copyright SOURCES and may not be reproduced without written permission. (For information use the Contact form.)

SOURCES.COM is an online portal and directory for journalists, news media, researchers and anyone seeking experts, spokespersons, and reliable information resources. Use SOURCES.COM to find experts, media contacts, news releases, background information, scientists, officials, speakers, newsmakers, spokespeople, talk show guests, story ideas, research studies, databases, universities, associations and NGOs, businesses, government spokespeople. Indexing and search applications by Ulli Diemer and Chris DeFreitas.

For information about being included in SOURCES as a expert or spokesperson see the FAQ . For partnerships, content and applications, and domain name opportunities contact us.


Sources home page