- Zhang Neuroscience Research Laboratories, Loma Linda University School of Medicine, Loma Linda, CA 92350 USA
- Department of Neurosurgery, Ankara Atatügrk Research and Education Hospital, Ankara 06800, Turkey
John H Zhang
Zhang Neuroscience Research Laboratories, Loma Linda University School of Medicine, Loma Linda, CA 92350 USA
DOI:10.4103/2152-7806.68706© 2010 Solaroglu I This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
How to cite this article: Solaroglu I, Zhang JH. The microRNAs: Small size, big value,…. Surg Neurol Int 25-Aug-2010;1:45
How to cite this URL: Solaroglu I, Zhang JH. The microRNAs: Small size, big value,…. Surg Neurol Int 25-Aug-2010;1:45. Available from: http://sni.wpengine.com/surgicalint_articles/the-micrornas-small-size-big-value/
During the past decade, the role of miRNAs in a variety of pathological processes including neuronal development, apoptosis, inflammation, and angiogenesis has been discovered. A few studies assessed the role of miRNAs in Alzheimer disease and amyotrophic lateral sclerosis. However, a significant attention has been focused on the role of miRNAs in brain tumor development and progression.
Although still not well characterized, recent evidences indicate that miRNAs can function as tumor suppressors and oncogenes, and may have a central role in tumorigenesis. For example, it is well established that both epidermal growth factor receptor (EGFR) and the phosphatidylinositol 3-kinase (PI3K)/Akt pathways play a major role in the pathogenesis of human gliomas. In glioblastoma multiforme (GBM), EGFR overexpression and/or expression of its constitutively activated variant, EGFRvIII, result in the downstream activation of the PI3K/Akt pathway. The Akt activation is correlated with the increased tumorigenicity and invasiveness in gliomas. It has been shown that miR-7 potently and directly regulates EGFR, and the Akt pathway is directly inhibited by miR-7. The Notch pathway, which also plays an important role in glioma cell survival, has been shown to be inhibited by miR-326.[
Moreover, aberrant expression of miRNAs has also been shown to be involved in tumorigenesis. EGFR amplification and phosphatase tensin homolog on chromosome ten (PTEN) loss are two common genetic alterations seen in gliomas. PTEN, a tumor suppressor gene, is lost in up to 70% of glioblastomas. Downregulation of miR-21 with a specific antisense oligonucleotide inhibits EGFR pathway and suppresses the growth of human GBM cells, independent of PTEN status.[
As summary, the miRNAs contribute to various cellular processes, but the detailed mechanisms remain poorly understood. A detailed knowledge of the biogenesis, functions, and targets of miRNAs would be important for a better understanding of their potential in the treatment or prevention of CNS disorders.
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