Table of Contents Author Guidelines Submit a Manuscript
BioMed Research International
Volume 2014, Article ID 374598, 11 pages
http://dx.doi.org/10.1155/2014/374598
Research Article

miR-375 Suppresses IGF1R Expression and Contributes to Inhibition of Cell Progression in Laryngeal Squamous Cell Carcinoma

1Department of Otorhinolaryngology, The First Affiliated Hospital of Sun Yat-sen University, Otorhinolaryngology Institute, Sun Yat-sen University, Guangzhou, China
2Department of Surgery, Queen Mary Hospital, The University of Hong Kong, Hong Kong
3Department of Otorhinolaryngology, The First People’s Hospital of Foshan, Foshan, China
4Otorhinolaryngology Hospital, The First Affiliated Hospital, Sun Yat-sen University, 58 Zhongshan Road II, Guangzhou, Guangdong 510080, China

Received 16 March 2014; Revised 17 June 2014; Accepted 24 June 2014; Published 12 August 2014

Academic Editor: Mouldy Sioud

Copyright © 2014 Jie Luo et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

MicroRNAs (miRNAs) are small noncoding RNA molecules which are involved in tumorigenesis and development. To investigate their role in primary laryngeal squamous cell carcinoma (LSCC), miRNA GeneChips were used to screen the differentially expressed miRNA, and then validated by real-time quantitative PCR in LSCC samples, we found that miR-375 was frequently downregulated in primary LSCC tissues. The tumor-suppressive effect of miR-375 was determined by in vitro assays; through gain-of-function studies we demonstrated that miR-375 can inhibit LSCC cell (SNU-48 and SNU-899) proliferation, motility, and invasion, and promote their apoptosis. In addition, bioinformatics tools TargetScan, PicTar, and Miranda were used to investigate the potential target of miR-375; bioinformatics analysis and dual-luciferase reporter assay indicated that IGF1R was a novel direct target of miR-375. Ectopic transfection of miR-375 led to a significant reduction in IGF1R and its downstream signaling molecule AKT at both the mRNA and protein levels in LSCC cells. Our results suggested that downregulation of miR-375 is one of the molecular mechanisms for the development and progression of LSCC by directly targeting IGF1R and affecting its downstream AKT signaling pathways. Furthermore, miR-375 and IGF1R may serve as a novel therapeutic target for LSCC.