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MiR-205 secondary structure.png
miR-205 microRNA secondary structure and sequence conservation
Symbol mir-205
Rfam RF00656
miRBase family MIPF0000058
Entrez 406988
HUGO 31583
OMIM 613147
Other data
RNA type microRNA
Domain(s) Eukaryota; Euteleostomi;
SO {{{SO}}}

In molecular biology miR-205 microRNA is a short RNA molecule. MicroRNAs function to regulate the expression levels of other genes by several mechanisms. They are involved in numerous cellular processes, including development, proliferation, and apoptosis. Currently, it is believed that miRNAs elicit their effect by silencing the expression of target genes.[1]

The miR-200 family (miR-200a, miR-200b, miR-200c, miR-141 and miR-429) and miR-205 are frequently silenced in advanced cancer. Studies has shown that—by targeting the transcriptional repressors of E-cadherin, ZEB1 and ZEB2 miR-205 is involved in epithelial to mesenchymal transition (EMT) and tumor invasion.[2]

Recently, miR-200 silencing was also reported in cancer stem cells, implying that miR-200 deregulation is a key event in multiple levels of tumor biology. The cause of miR-200 silencing in naturally occurring cancer cells, however, remains largely unknown.[3]

Genomic locations[edit]

Members of miR-200 family including miR -205 are found clustered at two locations in the human genome : 1142000 - 1144500 in chromosome 1 and 6942000 - 6944500 in chromosome 12. Short genomic distance between members suggests that they may function collaboratively and are highly related in sequence.[2]

miR-205 targets[edit]

Role of miR-205 in Cancer[edit]

Studies have demonstrated that miR-205 has a role in both normal development and cancer.

Breast Cancer[edit]

miR-205 was found to be highly expressed in stem cell-enriched populations from the mouse mammary gland, and thus may play a function in normal mammary stem cell maintenance.[4]

An increasing amount of experimental evidence shows that microRNAs can have a causal role in breast cancer tumorigenesis as a novel class of oncogenes or tumor suppressor genes, depending on the targets they regulate. It was found down-modulated in breast tumors compared with normal breast tissue.[5][6] This down regulation was also observed in breast cancer cell lines, including MCF-7 and MDA-MB-231 compared to the non-malignant cell line MCF-10A. It directly targets HER3 receptor, vascular endothelial growth factor A (VEGF-A) through interaction with putative binding site in the 3'-untranslated region (3'-UTR) of ErbB3 and VEGF-A. miR-205 inhibits the activation of the downstream mediator Akt. miR-205 was found to be able to interfere with the proliferative pathway mediated by HER receptor family.[5][6]

Ectopic expression of miR-205 significantly inhibits cell proliferation and anchorage independent growth, as well as cell invasion. Furthermore, miR-205 was shown to suppress lung metastasis in an animal model.[5]

Prostate cancer[edit]

Research has shown that miR-205 was significantly down-regulated in prostate cancer compared with match normal tissue. Its re-expression induced apoptosis and cell cycle arrest and resulted in a mesenchymal-to-epithelial transition, such as up-regulation of E-cadherin and reduction of cell locomotion and invasion, and in the down-regulation of several oncogenes known to be involved in disease progression (i.e., interleukin 6, caveolin-1, EZH2).[7]

It also impaired cell growth, migration, clonability, and invasiveness of prostate cancer cells. Micro-RNA-205 induced the expression of tumor suppressor genes IL-24 and IL-32 at both the messenger RNA and protein levels.

miR-205 exerts a tumor-suppressive effect in human prostate by counteracting epithelial-to-mesenchymal transition and reducing cell migration/invasion, at least in part through the down-regulation of protein kinase Cepsilon.[7] miR-205 activated tumor suppressor genes by targeting specific sites in their promoters. These results corroborate a newly identified function that miRNAs have in regulating gene expression at the transcriptional level. The specific activation of tumor suppressor genes (e.g., IL-24, IL-32) or other dysregulated genes by miRNA may contribute to a novel therapeutic approach for the treatment of prostate cancer.[8]

Bladder Cancer[edit]

From a study on transcriptional regulation of the miR-200 and miR-205 loci in bladder tumors and bladder cell lines, the miR-200 and miR-205 loci were found specifically silenced and gain promoter hypermethylation and repressive chromatin marks in muscle invasive bladder tumors and undifferentiated bladder cell lines. miR-200c expression is significantly correlated with early stage T1 bladder tumor progression, and propose miR-200 and miR-205 silencing and DNA hypermethylation as possible prognostic markers in bladder cancer.[3]

Lung Cancer[edit]

has-miR-205 was identified as a highly specific marker for squamous cell lung carcinoma. Has-miR-205 is a highly accurate marker for lung cancer of squamous histology. Diagnostic assay can provide highly accurate subclassification of NSCLC patients.[9]

Colorectal Cancer[edit]

Mir-205 has been found to be significantly deregulated in colorectal cancer. [10] Elevated expression levels of miR-205 have been shown to be associated with mucinous colorectal cancers and mucin-producing ulcerative colitis-associated colon cancers, but not with sporadic colonic adenocarcinoma that lack mucinous components. [11] Overexpression of miR-205 in an intestinal epithelial cell line (Caco-2 subclone) promoted accumulation of mucus-secreting goblet cell-like cells and mucin production and MUC2 mRNA expression were enhanced in-vitro. [11]

Cellular and molecular biological functions[edit]

It is still not clear how miR-205 plays in directing stem cell fate. A study on mammary-gland stem or progenitor cells showed that miR-205 over expression led to an expansion of the progenitor-cell population, decreased cell size and increased cellular proliferation.[4]

Research also shows miR-205 might regulate the expression of the tumor-suppressor protein PTEN. Several other putative and previously validated miR-205 targets include ZEB1 and ZEB2.[12]

Inhibition of microRNA-205 increased the number of phosphorylated FAK and phosphorylated Pax, and decreased filamentous actin. microRNA-205 has down-regulating effect on cell motility in NHCEKs.[13]

microRNA-205 (miR-205) and miR-184 coordinately regulate the lipid phosphatase SHIP2 for Akt survival signaling in keratinocytes.[14]

miR-205 also interacts with a specific target in the 3'-UTR sequence of MED1, which plays an important role in placental development, and silences MED1 expression in human trophoblasts exposed to hypoxia.[15]

Potentials in clinical applications[edit]

microRNA (miRNA) expression profiles are being intensively investigated for their involvement in carcinogenesis.

Detection of metastatic head and neck squamous cell carcinoma

The presence of cervical lymph node metastases in head and neck squamous cell carcinoma (HNSCC) is the strongest determinant of patient prognosis. Owing to the impact of nodal metastases on patient survival, a system for sensitive and accurate detection is required. Studies has shown that the expression of microRNA-205 (miR-205) is highly specific for squamous epithelium and can be used as a molecular marker for the detection of metastatic HNSCC.[16]

See also[edit]


  1. ^ Bartel DP (2004). "MicroRNAs: genomics, biogenesis, mechanism, and function.". Cell. 116 (2): 281–97. doi:10.1016/S0092-8674(04)00045-5. PMID 14744438. 
  2. ^ a b Gregory PA, Bert AG, Paterson EL, Barry SC, Tsykin A, Farshid G, Vadas MA, Khew-Goodall Y, Goodall GJ (2008). "The miR-200 family and miR-205 regulate epithelial to mesenchymal transition by targeting ZEB1 and SIP1.". Nat Cell Biol. 10 (5): 593–601. doi:10.1038/ncb1722. PMID 18376396. 
  3. ^ a b Wiklund ED, Bramsen JB, Hulf T, Dyrskjøt L, Ramanathan R, Hansen TB, Villadsen SB, Gao S, Ostenfeld MS, Borre M, Peter ME, Ørntoft TF, Kjems J, Clark SJ (2010). "Coordinated epigenetic repression of the miR-200 family and miR-205 in invasive bladder cancer.". Int J Cancer. 128 (6): 1327–34. doi:10.1002/ijc.25461. PMID 20473948. 
  4. ^ a b Greene SB, Herschkowitz JI, Rosen JM (2010). "The ups and downs of miR-205: Identifying the roles of miR-205 in mammary gland development and breast cancer". RNA Biol. 7 (3): 300–4. doi:10.4161/rna.7.3.11837. PMC 3008649Freely accessible. PMID 20436283. 
  5. ^ a b c Iorio MV, Casalini P, Piovan C, Di Leva G, Merlo A, Triulzi T, Ménard S, Croce CM, Tagliabue E (2009). "microRNA-205 regulates HER3 in human breast cancer.". Cancer Res. 69 (6): 2195–200. doi:10.1158/0008-5472.CAN-08-2920. PMID 19276373. 
  6. ^ a b Wu H, Zhu S, Mo YY (2009). "Suppression of cell growth and invasion by miR-205 in breast cancer.". Cell Res. 19 (4): 439–48. doi:10.1038/cr.2009.18. PMC 2664859Freely accessible. PMID 19238171. 
  7. ^ a b Gandellini P, Folini M, Longoni N, Pennati M, Binda M, Colecchia M, Salvioni R, Supino R, Moretti R, Limonta P, Valdagni R, Daidone MG, Zaffaroni N (2009). "miR-205 Exerts tumor-suppressive functions in human prostate through down-regulation of protein kinase Cepsilon.". Cancer Res. 69 (6): 2287–95. doi:10.1158/0008-5472.CAN-08-2894. PMID 19244118. 
  8. ^ Majid S, Dar AA, Saini S, Yamamura S, Hirata H, Tanaka Y, Deng G, Dahiya R (2010). "MicroRNA-205–directed transcriptional activation of tumor suppressor genes in prostate cancer". Cancer. 116 (24): 5637–49. doi:10.1002/cncr.25488. PMC 3940365Freely accessible. PMID 20737563. 
  9. ^ Lebanony D, Benjamin H, Gilad S, Ezagouri M, Dov A, Ashkenazi K, Gefen N, Izraeli S, Rechavi G, Pass H, Nonaka D, Li J, Spector Y, Rosenfeld N, Chajut A, Cohen D, Aharonov R, Mansukhani M (2009). "Diagnostic assay based on hsa-miR-205 expression distinguishes squamous from nonsquamous non-small-cell lung carcinoma.". J Clin Oncol. 27 (12): 2030–7. doi:10.1200/JCO.2008.19.4134. PMID 19273703. 
  10. ^ Kara M, Yumrutas O, Ozcan O, Celik O, Bozgeyik E, Bozgeyik I, Tasdemir S (2015). "Differential expression of cancer-associated genes and their regulatory miRNAs in colorectal carcinoma". Gene. 567 (1): 81–6. doi:10.1016/j.gene.2015.04.065. PMID 25925209. 
  11. ^ a b Eyking A, Reis H, Frank M, Gerken G, Schmid KW, Cario E (2016). "MiR-205 and MiR-373 Are Associated with Aggressive Human Mucinous Colorectal Cancer". PloS One. 11 (6): e0156871. doi:10.1371/journal.pone.0156871. PMC 4894642Freely accessible. PMID 27271572. 
  12. ^ Greene SB, Gunaratne PH, Hammond SM, Rosen JM (2010). "A putative role for microRNA-205 in mammary epithelial cell progenitors". J Cell Sci. 123 (Pt 4): 606–18. doi:10.1242/jcs.056812. PMC 2818197Freely accessible. PMID 20103531. 
  13. ^ Li J, Bai H, Zhu Y, Wang XY, Wang F, Zhang JW, Lavker RM, Yu J (2010). "Antagomir dependent microRNA-205 reduction enhances adhesion ability of human corneal epithelial keratinocytes.". Chin Med Sci J. 25 (2): 65–70. doi:10.1016/s1001-9294(10)60024-7. PMID 20598226. 
  14. ^ Yu J, Peng H, Ruan Q, Fatima A, Getsios S, Lavker RM (2010). "MicroRNA-205 promotes keratinocyte migration via the lipid phosphatase SHIP2". FASEB J. 24 (10): 3950–9. doi:10.1096/fj.10-157404. PMC 2996908Freely accessible. PMID 20530248. 
  15. ^ Mouillet JF, Chu T, Nelson DM, Mishima T, Sadovsky Y (2010). "MiR-205 silences MED1 in hypoxic primary human trophoblasts.". FASEB J. 24 (6): 2030–9. doi:10.1096/fj.09-149724. PMC 2874470Freely accessible. PMID 20065103. 
  16. ^ Fletcher AM, Heaford AC, Trask DK (2008). "Detection of metastatic head and neck squamous cell carcinoma using the relative expression of tissue-specific mir-205.". Transl Oncol. 1 (4): 202–8. PMC 2582169Freely accessible. PMID 19043531. 

Further reading[edit]

External links[edit]