MicroRNAs (miRNAs) are a family of small non-coding RNAs with the length of 21- to 25-nucleotides that regulate the expression of various kinds of cellular proteins by targeting their mRNA expression levels.

The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Ĭompeting interests: The authors have declared that no competing interests exist. 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.įunding: The authors acknowledge financial support from the National Basic Research Program of China grants 2007CB9470CB947001 the National Natural Science Foundation of China 3047030962 grants State High Technology Developing Project (2008AA02Z115), and the National Cancer Institute, National Institutes of Health (NIH) CA109460 grant. Received: DecemAccepted: MaPublished: April 22, 2011Ĭopyright: © 2011 Liu et al. PLoS ONE 6(4):Įditor: Alfons Navarro, University of Barcelona, Spain (2011) MiR-21 Induced Angiogenesis through AKT and ERK Activation and HIF-1α Expression. Therefore, we demonstrate that miR-21 induces tumor angiogenesis through targeting PTEN, leading to activate AKT and ERK1/2 signaling pathways, and thereby enhancing HIF-1α and VEGF expression HIF-1α is a key downstream target of miR-21 in regulating tumor angiogenesis.Ĭitation: Liu L-Z, Li C, Chen Q, Jing Y, Carpenter R, Jiang Y, et al. Moreover, inhibition of HIF-1α expression alone abolished miR-21-inducing tumor angiogenesis, indicating that HIF-1α is required for miR-21-upregulated angiogenesis. The AKT and ERK inhibitors, LY294002 and U0126, suppressed HIF-1α and VEGF expression and angiogenesis.

Overexpression of the miR-21 target, PTEN, also inhibited tumor angiogenesis by partially inactivating AKT and ERK and decreasing the expression of HIF-1 and VEGF. Inhibition of miR-21 by the antigomir blocked this process. AKT and extracellular regulated kinases (ERK) 1/2 are activated by miR-21.

We found that overexpression of miR-21 in DU145 cells increased the expression of HIF-1α and VEGF, and induced tumor angiogenesis. In this study, miR-21 was overexpressed by transfecting pre-miR-21 into human prostate cancer cells and tumor angiogenesis was assayed using chicken chorioallantoic membrane (CAM). Recent studies have indicated that miR-21 is one of the important miRNAs associated with tumor growth and metastasis, but the role and molecular mechanism of miR-21 in regulating tumor angiogenesis remain to be elucidated. MicroRNAs (miRNAs) are endogenous, small noncoding RNAs that play important roles in various cellular functions and tumor development.

Jing ling zhi san