4320199.pdf (884.76 kB)

MicroRNA-7 targets IGF1R (insulin-like growth factor 1 receptor) in tongue squamous cell carcinoma cells

Download (884.76 kB)
journal contribution
posted on 03.12.2013 by Lu Juiang, Xiqiang Lui, Zujian Chen, Yi Jin, Caroline E. Heidbreder, Antonia Kolokythas, Anxun Wang, Yang Dai, Xiaofeng Zhou
miR-7 (microRNA-7) has been characterized as a tumour suppressor in several human cancers. It targets a number of proto-oncogenes that contribute to cell proliferation and survival. However, the mechanism(s) by which miR-7 suppresses tumorigenesis in TSCC (tongue squamous cell carcinoma) is unknown. The present bioinformatics analysis revealed that IGF1R (insulin-like growth factor 1 receptor) mRNA is a potential target for miR-7. Ectopic transfection of miR-7 led to a significant reduction in IGF1R at both the mRNA and protein levels in TSCC cells. Knockdown of miR-7 in TSCC cells enhanced IGF1R expression. Direct targeting of miR-7 to three candidate binding sequences located in the 3'-untranslated region of IGF1R mRNA was confirmed using luciferase-reporter-gene assays. The miR-7-mediated down-regulation of IGF1R expression attenuated the IGF1 (insulin-like growth factor 1)-induced activation of Akt (protein kinase B) in TSCC cell lines, which in turn resulted in a reduction in cell proliferation and cell-cycle arrest, and an enhanced apoptotic rate. Taken together, the present results demonstrated that miR-7 regulates the IGF1R/Akt signalling pathway by post-transcriptional regulation of IGF1R. Our results indicate that miR-7 plays an important role in TSCC and may serve as a novel therapeutic target for TSCC patients.


This work was supported in part by the National Institutes of Health Public Health Service [grant numbers K22DE014847, RO1CA139596 and RO3CA135992] and the Prevent Cancer Foundation (to X.Z.).


Publisher Statement

The final version of record is available at http://www.biochemj.org/bj/default.htm


Portland Press





Issue date