Editing Insulin-like growth factor (section)

== Diseases affected by IGF ==

Studies of recent interest show that the Insulin/IGF axis play an important role in [[Senescence|aging]].<ref name="The genetics of ageing">{{cite journal | vauthors = Kenyon CJ | title = The genetics of ageing | journal = Nature | volume = 464 | issue = 7288 | pages = 504–12 | date = March 2010 | pmid = 20336132 | doi = 10.1038/nature08980 | bibcode = 2010Natur.464..504K | s2cid = 2781311 }}</ref> [[Nematode]]s, [[Drosophila melanogaster|fruit-flies]], and other organisms have an increased life span when the gene equivalent to the mammalian insulin is [[Gene knockout|knocked out]].  It is somewhat difficult to relate this finding to the mammals, however, because in the smaller organism there are many genes (at least 37 in the nematode ''Caenorhabditis elegans''<ref name="pmid11274053">
{{cite journal | vauthors = Pierce SB, Costa M, Wisotzkey R, Devadhar S, Homburger SA, Buchman AR, Ferguson KC, Heller J, Platt DM, Pasquinelli AA, Liu LX, Doberstein SK, Ruvkun G | display-authors = 6 | title = Regulation of DAF-2 receptor signaling by human insulin and ins-1, a member of the unusually large and diverse C. elegans insulin gene family | journal = Genes & Development | volume = 15 | issue = 6 | pages = 672–86 | date = March 2001 | pmid = 11274053 | pmc = 312654 | doi = 10.1101/gad.867301 }}</ref>) that are "insulin-like" or "IGF-1-like", whereas in the mammals insulin-like proteins comprise only seven members ([[insulin]], IGFs, [[relaxin]]s, EPIL, and relaxin-like factor).<ref>{{Cite journal |last1=Honnen |first1=Sebastian J. |last2=Büchter |first2=Christian |last3=Schröder |first3=Verena |last4=Hoffmann |first4=Michael |last5=Kohara |first5=Yuji |last6=Kampkötter |first6=Andreas |last7=Bossinger |first7=Olaf |date=2012-02-16 |title=C. elegans VANG-1 Modulates Life Span via Insulin/IGF-1-Like Signaling |journal=PLOS ONE |volume=7 |issue=2 |pages=e32183 |doi=10.1371/journal.pone.0032183 |issn=1932-6203 |pmc=3281126 |pmid=22359667|bibcode=2012PLoSO...732183H |doi-access=free }}</ref> The human insulin-like genes have apparently distinct roles with some but less crosstalk presumably because there are multiple insulin-receptor-like proteins in humans. Simpler organisms typically have fewer receptors; for example, only one insulin-like receptor exists in the nematode ''C. elegans''.<ref>{{cite journal | vauthors = Kimura KD, Tissenbaum HA, Liu Y, Ruvkun G | title = daf-2, an insulin receptor-like gene that regulates longevity and diapause in Caenorhabditis elegans | journal = Science | volume = 277 | issue = 5328 | pages = 942–6 | date = August 1997 | pmid = 9252323 | doi = 10.1126/science.277.5328.942 }}</ref> Additionally, ''C. elegans'' do not have specialized organs such as the ([[Islets of Langerhans]]), which sense insulin in response to glucose homeostasis. Moreover, IGF1 affects lifespan in nematodes by causing [[Dauer larva|dauer]] formation, a developmental stage of ''C. elegans'' larva. There is no mammalian correlate. Therefore, it is an open question as to whether either IGF-1 or insulin in the mammal may perturb aging, although there is the suggestion that dietary restriction phenomena may be related.<ref>{{Cite journal |last1=Venz |first1=Richard |last2=Pekec |first2=Tina |last3=Katic |first3=Iskra |last4=Ciosk |first4=Rafal |last5=Ewald |first5=Collin Yvès |date=2021-09-10 |title=End-of-life targeted degradation of DAF-2 insulin/IGF-1 receptor promotes longevity free from growth-related pathologies |journal=eLife |volume=10 |pages=e71335 |doi=10.7554/eLife.71335 |issn=2050-084X |pmc=8492056 |pmid=34505574 |doi-access=free }}</ref>

Other studies are beginning to uncover the important role the IGFs play in diseases such as [[cancer]] and [[diabetes]], showing for instance that IGF-1 stimulates growth of both prostate and breast cancer cells.  Researchers are not in complete agreement about the degree of cancer risk that IGF-1 poses.<ref name="pmid9483550">
{{cite journal | vauthors = Woods AG, Guthrie KM, Kurlawalla MA, Gall CM | title = Deafferentation-induced increases in hippocampal insulin-like growth factor-1 messenger RNA expression are severely attenuated in middle aged and aged rats | journal = Neuroscience | volume = 83 | issue = 3 | pages = 663–8 | date = April 1998 | pmid = 9483550 | doi = 10.1016/S0306-4522(97)00539-3 | s2cid = 208782267 }}</ref>