MicroRNA-7 inhibits tumor growth and metastasis by targeting the phosphoinositide 3-kinase/Akt pathway in hepatocellular carcinoma
MicroRNAs (miRNAs) are known to be involved in carcinogenesis and tumor progression in hepatocellular carcinoma (HCC). Recently, microRNA‐7 (miR‐7) has been proven to play a substantial role in glioblastoma and breast cancer, but its functions in the context of HCC remain unknown. Here, we demonstra...
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Published in | Hepatology (Baltimore, Md.) Vol. 55; no. 6; pp. 1852 - 1862 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
Hoboken
Wiley Subscription Services, Inc., A Wiley Company
01.06.2012
Wiley Wolters Kluwer Health, Inc |
Subjects | |
Online Access | Get full text |
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Summary: | MicroRNAs (miRNAs) are known to be involved in carcinogenesis and tumor progression in hepatocellular carcinoma (HCC). Recently, microRNA‐7 (miR‐7) has been proven to play a substantial role in glioblastoma and breast cancer, but its functions in the context of HCC remain unknown. Here, we demonstrate that miR‐7 inhibits HCC cell growth and metastasis invitro and in vivo. We first screened and identified a novel miR‐7 target, phosphoinositide 3‐kinase catalytic subunit delta (PIK3CD). Overexpression of miR‐7 would specifically and markedly down‐regulate its expression. miR‐7‐overexpressing subclones showed significant cell growth inhibition by G0/G1‐phase cell‐cycle arrest and significant impairment of cell migration in vitro. To identify the mechanisms, we investigated the phosphoinositide 3‐kinase (PI3K)/Akt pathway and found that Akt, mammalian target of rapamycin (mTOR), and p70S6K were down‐regulated, whereas 4EBP1 was up‐regulated in miR‐7‐overexpressing subclones. We also identified two novel, putative miR‐7 target genes, mTOR and p70S6K, which further suggests that miR‐7 may be a key regulator of the PI3K/Akt pathway. In xenograft animal experiments, we found that overexpressed miR‐7 effectively repressed tumor growth (3.5‐fold decrease in mean tumor volume; n = 5) and abolished extrahepatic migration from liver to lung in a nude mouse model of metastasis (n = 5). The number of visible nodules on the lung surface was reduced by 32‐fold. A correlation between miR‐7 and PIK3CD expression was also confirmed in clinical samples of HCC. Conclusion: These findings indicate that miR‐7 functions as a tumor suppressor and plays a substantial role in inhibiting the tumorigenesis and reversing the metastasis of HCC through the PI3K/Akt/mTOR‐signaling pathway in vitro and in vivo. By targeting PIK3CD, mTOR, and p70S6K, miR‐7 efficiently regulates the PI3K/Akt pathway. Given these results, miR‐7 may be a potential therapeutic or diagnostic/prognostic target for treating HCC. (HEPATOLOGY 2012;55:1852–1862) |
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Bibliography: | ark:/67375/WNG-06BJ2NGN-G This work was supported by the National Basic Research Program of China (973 Program) (grant no. 2010CB529902) and the National Natural Science Foundation of China (grant no. 81172030). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript for this article. Potential conflict of interest: Nothing to report. ArticleID:HEP25576 National Natural Science Foundation of China - No. 81172030 istex:0A35FDB5C9B6E714491EBC57222B33AB16D2DAAB National Basic Research Program of China - No. 973 Program; No. 2010CB529902 fax: 86‐21‐65643627 ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 14 content type line 23 |
ISSN: | 0270-9139 1527-3350 1527-3350 |
DOI: | 10.1002/hep.25576 |