Journal Article

MiR-145 modulates multiple components of the insulin-like growth factor pathway in hepatocellular carcinoma

Priscilla T.-Y. Law, Arthur K.-K. Ching, Anthony W.-H. Chan, Queenie W.-L. Wong, Chun-Kwok Wong, Ka-Fai To and Nathalie Wong

in Carcinogenesis

Volume 33, issue 6, pages 1134-1141
Published in print June 2012 | ISSN: 0143-3334
Published online March 2012 | e-ISSN: 1460-2180 | DOI: http://dx.doi.org/10.1093/carcin/bgs130
MiR-145 modulates multiple components of the insulin-like growth factor pathway in hepatocellular carcinoma

More Like This

Show all results sharing this subject:

  • Clinical Cytogenetics and Molecular Genetics

GO

Show Summary Details

Preview

Profiling of microRNA expression in human cancers has highlighted downregulation of miR-145 as a common event in epithelial malignancies. Here, we describe recurrent underexpression of miR-145 in hepatocellular carcinoma (HCC) and the identification of a biological pathway by which miR-145 exerts its functional effects in liver tumorigenesis. In a cohort of 80 HCC patients, quantitative reverse transcription polymerase chain reaction corroborated reduced miR-145 expression in 50% of tumors, which also correlated with a shorter disease-free survival of patients. One HCC tumor analyzed with low endogenous miR-145 was propagated as cell line. This in vitro model HKCI-C2 maintained low miR-145 level and upon restoration of miR-145 expression, a consistent inhibitory effect on cell viability and proliferation was readily found. Flow cytometric analysis indicated that miR-145 re-expression could induce G2–M cell cycle arrest and apoptosis. Multiple in silico algorithms predicted that miR-145 could target a number of genes along the insulin-like growth factor (IGF) signaling, including insulin receptor substrate (IRS1)-1, IRS2 and insulin-like growth factor 1 receptor. We found protein expression of these putative targets was concordantly downregulated in the presence of miR-145. Luciferase reporter assay further verified direct target association of miR-145 to specific sites of the IRS1 and IRS2 3′-untranslated regions. Subsequent analysis also affirmed miR-145 modulation on the IGF signaling cascade by reducing its downstream mediator, namely the active β-catenin level. Taken together, our study shows for the first time the pleiotropic effect of miR-145 in targeting multiple components of the oncogenic IGF signaling pathway in HCC.

Journal Article.  4399 words.  Illustrated.

Subjects: Clinical Cytogenetics and Molecular Genetics

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.