View source for MiR-27

{{Short description|Family of microRNA precursors found in animals}}
{{Infobox rfam
| Name = miR-27
| image = Mir-27_SS.png
| width =
| caption = Conserved secondary structure of miR-27 prescursor
| Symbol = miR-27
| AltSymbols =
| Rfam = RF00644
| miRBase = MI0000085
| miRBase_family = MIPF0000036
| RNA_type = miRNA
| Tax_domain = [[Animalia]]
| GO =
| SO =
| CAS_number =
| EntrezGene = 407018
| HGNCid = 31613
| OMIM =
| PDB =
| RefSeq =
| Chromosome = 19
| Arm =
| Band =
| LocusSupplementaryData =
}} {{lowercase}}
'''miR-27''' is a family of [[microRNA]] precursors found in animals, including [[human]]s.<ref>{{cite journal|last=Landgraf|first=P|author2=Rusu, M |author3=Sheridan, R |author4=Sewer, A |author5=Iovino, N |author6=Aravin, A |author7=Pfeffer, S |author8=Rice, A|title=A mammalian microRNA expression atlas based on small RNA library sequencing.|journal=Cell|date=Jun 29, 2007|volume=129|issue=7|pages=1401–14|pmid=17604727|doi=10.1016/j.cell.2007.04.040|pmc=2681231|display-authors=etal}}</ref> MicroRNAs are typically transcribed as ~70 [[nucleotide]] precursors and subsequently processed by the [[Dicer]] enzyme to give a ~22 nucleotide product.<ref>{{cite journal | last = Ambros | first = V | year = 2001 | title = microRNAs: tiny regulators with great potential | journal = Cell | volume = 107 | pages = 823&ndash;826 | pmid = 11779458 | doi = 10.1016/S0092-8674(01)00616-X | issue = 7| s2cid = 14574186 | doi-access = free }}</ref> The excised region or, mature product, of the miR-27 precursor is the microRNA mir-27.
''[[Herpesvirus saimiri]]'' expresses several non-coding RNAs ([[HSUR]]s) which have been found to significantly reduce the level of mir-27 in a host cell.<ref>{{cite journal|last=Cazalla|first=D|author2=Yario, T |author3=Steitz, JA |title=Down-regulation of a host microRNA by a Herpesvirus saimiri noncoding RNA.|journal=Science|date=Jun 18, 2010|volume=328|issue=5985|pages=1563–6|pmid=20558719|doi=10.1126/science.1187197|pmc=3075239|bibcode=2010Sci...328.1563C}}</ref> It has been proposed that miR-27 operates together with miR-23 and mir-24 in a co-operative cluster.<ref>{{cite journal|last=Chhabra|first=R|author2=Dubey, R |author3=Saini, N |title=Cooperative and individualistic functions of the microRNAs in the miR-23a~27a~24-2 cluster and its implication in human diseases.|journal=Molecular Cancer|date=Sep 3, 2010|volume=9|pages=232|pmid=20815877|doi=10.1186/1476-4598-9-232|pmc=2940846|doi-access=free}}</ref>
==Regulation of adipocyte differentiation==
miR-27 is one of a number of microRNAs implicated in [[cholesterol]] homeostasis and [[fatty acid metabolism]].<ref>{{cite journal|last=Fernández-Hernando|first=C|author2=Suárez, Y |author3=Rayner, KJ |author4=Moore, KJ |title=MicroRNAs in lipid metabolism.|journal=Current Opinion in Lipidology|date=April 2011|volume=22|issue=2|pages=86–92|pmid=21178770|doi=10.1097/MOL.0b013e3283428d9d|pmc=3096067}}</ref> The miR-27 gene family has been shown to be downregulated during the differentiation of adipocytes. miR-27 inhibits adipocyte formation when overexpressed, acting by blocking the expression of two main regulators of [[adipogenesis]].<ref name="pmid19348006">{{cite journal|vauthors=Lin Q, Gao Z, Alarcon RM, Ye J, Yun Z | title=A role of miR-27 in the regulation of adipogenesis. | journal=FEBS J | year= 2009 | volume= 276 | issue= 8 | pages= 2348–58 | pmid=19348006 | doi= 10.1111/j.1742-4658.2009.06967.x| pmc= 5330386}}</ref> MicroRNAs miR-27a and -27b have been found to negatively regulate adipocyte differentiation through regulation of the [[peroxisome proliferator-activated receptor gamma|peroxisome proliferator-activated receptor gamma (PPARγ)]] post-transcriptionally, as well as [[CEBPA|C/EBP alpha]] in the case of miR-27b.<ref name="pmid20060380">{{cite journal |vauthors=Kim SY, Kim AY, Lee HW, Son YH, Lee GY, Lee JW, etal | title=miR-27a is a negative regulator of adipocyte differentiation via suppressing PPARgamma expression. | journal=Biochem Biophys Res Commun | year= 2010 | volume= 392 | issue= 3 | pages= 323–8 | pmid=20060380 | doi=10.1016/j.bbrc.2010.01.012 | url=https://pubmed.ncbi.nlm.nih.gov/20060380  }}</ref>   miR-27 can be identified both as an adipogenic inhibitor and as playing an important role in the development of obesity.<ref name="pmid19348006"/>
==Wnt signalling pathway==
miR-27 is an activator of the [[Wnt signalling pathway]], affecting the differentiation of mesenchymal stem cells into osteoblasts.<ref>{{cite journal|last=Wang|first=T|author2=Xu, Z|title=miR-27 promotes osteoblast differentiation by modulating Wnt signaling.|journal=Biochemical and Biophysical Research Communications|date=Nov 12, 2010|volume=402|issue=2|pages=186–9|pmid=20708603|doi=10.1016/j.bbrc.2010.08.031}}</ref> miR-27 has been found to target and inhibit gene expression of the [[adenomatous polyposis coli|adenomatous polyposis coli (APC)]] protein, enabling it to regulate osteoblast differentiation. Expression levels of miR-27 are positively correlated with [[beta-catenin]],<ref name="pmid20708603">{{cite journal|vauthors=Wang T, Xu Z | title=miR-27 promotes osteoblast differentiation by modulating Wnt signaling. | journal=Biochem Biophys Res Commun | year= 2010 | volume= 402 | issue= 2 | pages= 186–9 | pmid=20708603 | doi=10.1016/j.bbrc.2010.08.031 | url=https://pubmed.ncbi.nlm.nih.gov/20708603  }}</ref> a key protein in Wnt signalling. There is activation of Wnt signalling through nuclear accumulation of this protein, which is in response to inhibition of the beta-catenin destruction complex. This in turn is brought about by APC inhibition of miR-27.<ref name="pmid20708603"/>
==Cancer Regulation==
miR-27 is known to regulate components involved in numerous types of cancer, including [[breast cancer|breast]]<ref>{{cite journal|last=Li|first=X |author2=Mertens-Talcott, SU |author3=Zhang, S |author4=Kim, K |author5=Ball, J |author6=Safe, S|title=MicroRNA-27a Indirectly Regulates Estrogen Receptor {alpha} Expression and Hormone Responsiveness in MCF-7 Breast Cancer Cells.|journal=Endocrinology|date=June 2010|volume=151|issue=6|pages=2462–73|pmid=20382698|doi=10.1210/en.2009-1150|pmc=2875816}}</ref><ref>{{cite journal|last=Guttilla|first=IK|author2=White, BA|title=Coordinate regulation of FOXO1 by miR-27a, miR-96, and miR-182 in breast cancer cells.|journal=The Journal of Biological Chemistry|date=Aug 28, 2009|volume=284|issue=35|pages=23204–16|pmid=19574223|doi=10.1074/jbc.M109.031427|pmc=2749094|doi-access=free }}</ref> and [[ovarian cancer|ovarian]].<ref>{{cite journal|last=Kontorovich|first=T|author2=Levy, A |author3=Korostishevsky, M |author4=Nir, U |author5=Friedman, E |title=Single nucleotide polymorphisms in miRNA binding sites and miRNA genes as breast/ovarian cancer risk modifiers in Jewish high-risk women.|journal=International Journal of Cancer|date=Aug 1, 2010|volume=127|issue=3|pages=589–97|pmid=19950226|doi=10.1002/ijc.25065|s2cid=29984487}}</ref> miR-27a has been identified as an oncogenic microRNA and, specifically, is highly expressed in breast cancer cells. mir-27b expression is associated with survival in triple negative breast cancer patients.<ref>{{Cite journal|last1=Lánczky|first1=András|last2=Nagy|first2=Ádám|last3=Bottai|first3=Giulia|last4=Munkácsy|first4=Gyöngyi|last5=Szabó|first5=András|last6=Santarpia|first6=Libero|last7=Győrffy|first7=Balázs|date=2016-12-01|title=miRpower: a web-tool to validate survival-associated miRNAs utilizing expression data from 2178 breast cancer patients|journal=Breast Cancer Research and Treatment|volume=160|issue=3|pages=439–446|doi=10.1007/s10549-016-4013-7|issn=1573-7217|pmid=27744485|s2cid=11165696}}</ref> Inhibition of miR-27 by antisense molecules decreases cell proliferation.<ref name="pmid18006846">{{cite journal|vauthors=Mertens-Talcott SU, Chintharlapalli S, Li X, Safe S | title=The oncogenic microRNA-27a targets genes that regulate specificity protein transcription factors and the G2-M checkpoint in MDA-MB-231 breast cancer cells. | journal=Cancer Res | year= 2007 | volume= 67 | issue= 22 | pages= 11001–11 | pmid=18006846 | doi=10.1158/0008-5472.CAN-07-2416 | doi-access=free }}</ref> Antisense RNA directed against miR-27a has been shown to decrease the percentage of cells in S phase whilst also increasing those in the G2-M phase.<ref name="pmid19574223">{{cite journal|vauthors=Guttilla IK, White BA | title=Coordinate regulation of FOXO1 by miR-27a, miR-96, and miR-182 in breast cancer cells. | journal=J Biol Chem | year= 2009 | volume= 284 | issue= 35 | pages= 23204–16 | pmid=19574223 | doi=10.1074/jbc.M109.031427 | pmc=2749094 | doi-access=free }}</ref>
The [[FOXO|FOXO (Forkhead Box O)]] gene sub-family encodes tumour-suppressive transcription factors that regulate multiple aspects of cell cycle progression and survival. FOXO1 protein expression is down-regulated in breast tumour tissue samples; miR-27a has been identified as one of three miRNAS (along with miR-96 and miR-182) which directly target FOXO1 and regulate its endogenous expression. Suppression of miR-27a results in a FOXO1 protein increase and a consequent cell number decrease.<ref name="pmid19574223"/>
==References==
{{reflist|30em}}
==External links==
* {{Rfam|id=RF00644|name=microRNA mir-27}}
{{miRNA precursor families}}
[[Category:MicroRNA]]