Signaling autocrine

Autocrine signaling occurs when a growth factor produced by a cell binds to a receptor on that same cell. 

Fig. 3.5. Endocrine, paracrine and autocrine signal transduction, a) endocrine signal transduction the hormone is formed in the specialized endocrine tissue, released into the extracellular medium and transported via the circulatory system to the target cells, b) paracrine signal transduction the hormone reaches the target cell, which is found in close juxtaposition to the hormone producing cell, via diffusion, c) autocrine signal transduction the hormone acts on the same ceU type as the one in which it is produced.

In autocrine signaling, cells of the same type commimicate with one other. The hormone produced by the signaling cell affects a cell of the same type by binding to recep-... 

IL-9 can support cell proliferation in the absence of an antigen or APC, Overproduction of it may lead to T-cell tumors, particularly of Th2 lymphocytes. In certain lymphomas, such as Hodgkin s lymphoma, it may act as an autocrine signal for cellular proliferation. IL-9 may play a role in the development of acute myeloblastic leukemia by stimulating leukemic cells to enter the S-phase rather than preventing cell death. In addition, IL-9 acts synergisticaUy with stem cell factor for recruitmg quiescent leukemic cells in the cell cycle. ... 

In autocrine signaling, cells of the same type communicate with one another. The hormone produced by the signaling cell affects a cell of the same type by binding to receptors on these cells and initiating an intracellular signal cascade. If an autocrine hormone is secreted simultaneously by many cells then a strong response occurs in the cells. Autocrine mechanisms are of particular importance in the immune response (see Chapter 11). 

In autocrine signaling, cells respond to substances that they themselves release. Some growth factors act in this fashion, and cultured cells often secrete growth factors that stimulate their own growth and proliferation. This type of signaling is particularly common in tumor cells, many of which overproduce and release growth factors that stimulate inappropriate, unregulated proliferation of themselves as well as adjacent nontumor cells this process may lead to formation of a tumor mass. 

Signaling by soluble extracellular molecules can be classified Into three types endocrine, paracrine, and autocrine. Describe how these three methods of cellular signaling differ. Growth hormone Is secreted from the pituitary, which Is located at the base of the brain, and acts through growth hormone receptors located on the liver. Is this an example of endocrine, paracrine, or autocrine signaling Why ... 

Autocrine signaling occurs when the same cell produces both the receptor and its ligand. 

Liu C. Human herpesvirus 8 (HHV-8)-encoded cytokines induce expression of and autocrine signaling by vascular endothelial growth factor (VEGF) in HHV- 8-infected primary-effusion lymphoma cell lines and mediate VEGF- independent antiapoptotic effects. J Virol 2001 75(22) 10933-40. 

Marek L, Ware KE, Fritzsche A. et al. Fibroblast growth factor (FGF) and FGF receptor-mediated autocrine signaling in non-small-cell lung cancer cells. Mol Pharmacol 2009 75 196-207. 

Cells receive extracellular cues from ligands circulating in the bloodstream as well as those released from neighboring cells. Autocrine signaling occurs when the cell secretes a ligand that eventually binds... 

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