Editing MicroRNA (section)

===Cancer===
[[File:Role of miRNA in a cancer cell.svg|right|thumb|Role of miRNA in a cancer cell]]

The first human disease known to be associated with miRNA deregulation was [[chronic lymphocytic leukemia]].<ref name="pmid15284443">{{cite journal | vauthors = Calin GA, Liu CG, Sevignani C, Ferracin M, Felli N, Dumitru CD, Shimizu M, Cimmino A, Zupo S, Dono M, Dell'Aquila ML, Alder H, Rassenti L, Kipps TJ, Bullrich F, Negrini M, Croce CM | title = MicroRNA profiling reveals distinct signatures in B cell chronic lymphocytic leukemias | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 101 | issue = 32 | pages = 11755–11760 | date = August 2004 | pmid = 15284443 | pmc = 511048 | doi = 10.1073/pnas.0404432101 | doi-access = free | bibcode = 2004PNAS..10111755C }}</ref> Many other miRNAs also have links with cancer and accordingly are sometimes referred to as "[[oncomir]]s".<ref>{{cite journal | vauthors = Velle A, Pesenti C, Grassi T, Beltrame L, Martini P, Jaconi M, Agostinis F, Calura E, Katsaros D, Borella F, Fruscio R, D'Incalci M, Marchini S, Romualdi C | title = A comprehensive investigation of histotype-specific microRNA and their variants in Stage I epithelial ovarian cancers | journal = International Journal of Cancer | volume = 152 | issue = 9 | pages = 1989–2001 | date = May 2023 | pmid = 36541726 | doi = 10.1002/ijc.34408 | s2cid = 255034585 | doi-access = free | hdl = 11577/3478062 | hdl-access = free }}</ref> In malignant B cells miRNAs participate in pathways fundamental to B cell development like [[B-cell receptor]] (BCR) signalling, B-cell migration/adhesion, cell-cell interactions in immune niches and the production and class-switching of immunoglobulins. MiRNAs influence B cell maturation, generation of pre-, marginal zone, follicular, B1, plasma and memory B cells.<ref name="pmid36010971">{{cite journal | vauthors = Kyriakidis I, Kyriakidis K, Tsezou A | title = MicroRNAs and the Diagnosis of Childhood Acute Lymphoblastic Leukemia: Systematic Review, Meta-Analysis and Re-Analysis with Novel Small RNA-Seq Tools | journal = Cancers | volume = 14 | issue = 16 | pages = 3976 | date = August 2022 | pmid = 36010971 | pmc = 9406077 | doi = 10.3390/cancers14163976 | doi-access = free }}</ref>

Another role for miRNA in cancers is to use their expression level for prognosis. In [[non-small-cell lung carcinoma|NSCLC]] samples, low [[MiR-324-5p|miR-324]]<nowiki/>a levels may serve as an indicator of poor survival.<ref name="pmid21748820">{{cite journal | vauthors = Võsa U, Vooder T, Kolde R, Fischer K, Välk K, Tõnisson N, Roosipuu R, Vilo J, Metspalu A, Annilo T | title = Identification of miR-374a as a prognostic marker for survival in patients with early-stage nonsmall cell lung cancer | journal = Genes, Chromosomes & Cancer | volume = 50 | issue = 10 | pages = 812–22 | date = October 2011 | pmid = 21748820 | doi = 10.1002/gcc.20902 | s2cid = 9746594 | url = https://zenodo.org/record/1119590 }}</ref> Either high miR-185 or low miR-133b levels may correlate with [[metastasis]] and poor survival in [[colorectal cancer]].<ref name="pmid21573504">{{cite journal | vauthors = Akçakaya P, Ekelund S, Kolosenko I, Caramuta S, Ozata DM, Xie H, Lindforss U, Olivecrona H, Lui WO | title = miR-185 and miR-133b deregulation is associated with overall survival and metastasis in colorectal cancer | journal = International Journal of Oncology | volume = 39 | issue = 2 | pages = 311–18 | date = August 2011 | pmid = 21573504 | doi = 10.3892/ijo.2011.1043 | doi-access = free }}</ref>

Furthermore, specific miRNAs may be associated with certain histological subtypes of colorectal cancer. For instance, expression levels of miR-205 and miR-373 have been shown to be increased in mucinous colorectal cancers and mucin-producing Ulcerative Colitis-associated colon cancers, but not in sporadic colonic adenocarcinoma that lack mucinous components.<ref name="pmid27271572">{{cite journal | vauthors = Eyking A, Reis H, Frank M, Gerken G, Schmid KW, Cario E | title = MiR-205 and MiR-373 Are Associated with Aggressive Human Mucinous Colorectal Cancer | journal = PLOS ONE | volume = 11 | issue = 6 | pages = e0156871 | year = 2016 | pmid = 27271572 | pmc = 4894642 | doi = 10.1371/journal.pone.0156871 | bibcode = 2016PLoSO..1156871E | doi-access = free }}</ref> In-vitro studies suggested that miR-205 and miR-373 may functionally induce different features of mucinous-associated neoplastic progression in intestinal epithelial cells.<ref name="pmid27271572"/>

Hepatocellular carcinoma cell proliferation may arise from miR-21 interaction with MAP2K3, a tumor repressor gene.<ref name="pmid24112539">MicroRNA-21 promotes hepatocellular carcinoma HepG2 cell proliferation through repression of mitogen-activated protein kinase-kinase 3. Guangxian Xu et al., 2013</ref> Optimal treatment for cancer involves accurately identifying patients for risk-stratified therapy. Those with a rapid response to initial treatment may benefit from truncated treatment regimens, showing the value of accurate disease response measures. Cell-free circulating miRNAs (cimiRNAs) are highly stable in blood, are overexpressed in cancer and are quantifiable within the diagnostic laboratory. In classical [[Hodgkin lymphoma]], plasma miR-21, miR-494, and miR-1973 are promising disease response biomarkers.<ref>{{cite journal | vauthors = Jones K, Nourse JP, Keane C, Bhatnagar A, Gandhi MK | title = Plasma microRNA are disease response biomarkers in classical Hodgkin lymphoma | journal = Clinical Cancer Research | volume = 20 | issue = 1 | pages = 253–64 | date = January 2014 | pmid = 24222179 | doi = 10.1158/1078-0432.CCR-13-1024 | doi-access = free }}</ref> Circulating miRNAs have the potential to assist clinical decision making and aid interpretation of [[positron emission tomography]] combined with [[computerized tomography]]. They can be performed at each consultation to assess disease response and detect relapse.

MicroRNAs have the potential to be used as tools or targets for treatment of different cancers.<ref name= Hosseinahli2018>{{cite journal | vauthors = Hosseinahli N, Aghapour M, Duijf PH, Baradaran B | title = Treating cancer with microRNA replacement therapy: A literature review | journal = Journal of Cellular Physiology | volume = 233 | issue = 8 | pages = 5574–5588 | date = August 2018 | pmid = 29521426 | doi = 10.1002/jcp.26514 | s2cid = 3766576 | doi-access = free }}</ref> The specific microRNA, miR-506 has been found to work as a tumor antagonist in several studies.  A significant number of cervical cancer samples were found to have downregulated expression of miR-506.  Additionally, miR-506 works to promote apoptosis of cervical cancer cells, through its direct target hedgehog pathway transcription factor, Gli3.<ref name="Liu_2014">{{cite journal | vauthors = Liu G, Sun Y, Ji P, Li X, Cogdell D, Yang D, Parker Kerrigan BC, Shmulevich I, Chen K, Sood AK, Xue F, Zhang W | title = MiR-506 suppresses proliferation and induces senescence by directly targeting the CDK4/6-FOXM1 axis in ovarian cancer | journal = The Journal of Pathology | volume = 233 | issue = 3 | pages = 308–18 | date = July 2014 | pmid = 24604117 | pmc = 4144705 | doi = 10.1002/path.4348 }}</ref><ref name="Wen_2015">{{cite journal | vauthors = Wen SY, Lin Y, Yu YQ, Cao SJ, Zhang R, Yang XM, Li J, Zhang YL, Wang YH, Ma MZ, Sun WW, Lou XL, Wang JH, Teng YC, Zhang ZG | title = miR-506 acts as a tumor suppressor by directly targeting the hedgehog pathway transcription factor Gli3 in human cervical cancer | journal = Oncogene | volume = 34 | issue = 6 | pages = 717–25 | date = February 2015 | pmid = 24608427 | doi = 10.1038/onc.2014.9 | s2cid = 20603801 | doi-access = free }}</ref>