Adenosine-to-inosine RNA editing mediated by ADARs in Esophageal Squamous Cell Carcinoma (Cancer Research, Dec 2013)

Esophageal Squamous Cell Carcinoma (ESCC), the major histological form of esophageal cancer, is a heterogeneous tumor displaying a complex variety of genetic and epigenetic changes. Aberrant RNA editing of adenosine-to-inosine (A-to-I) as it is catalyzed by adenosine deaminases (ADARs) represents a common post-transcriptional modification in certain human diseases. In this study, we investigated the status and role of ADARs and altered A-to-I RNA editing in ESCC tumorigenesis. Among the three ADAR enzymes expressed in human cells only ADAR1 was overexpressed in primary ESCC tumors. ADAR1 overexpression was due to gene amplification. ESCC patients with tumoral overexpression of ADAR1 displayed a poor prognosis. In vitro and in vivo functional assays established that ADAR1 functions as an oncogene during ESCC progression. Differential expression of ADAR1 resulted in altered gene-specific editing activities, as reflected by hyperediting of FLNB and AZIN1 messages in primary ESCC. Notably, the edited form of AZIN1 conferred a gain-of-function phenotype associated with aggressive tumor behavior. Our findings reveal that altered gene-specific A-to-I editing events mediated by ADAR1 drive the development of ESCC, with potential implications in diagnosis, prognosis and treatment of this disease.


Yan-Ru Qin1,*,#,Jun-Jing Qiao1,2,*,Tim Hon Man Chan2, Ying-Hui Zhu3, Fang-Fang Li4, Haibo Liu5, Jing Fei2, Yan Li3, Xin-Yuan Guan3,6,#, Leilei Chen2,#

1Department of Clinical Oncology, the First Affiliated Hospital, Zhengzhou University, Zhengzhou, China
2Cancer Science Institute of Singapore, National University of Singpaore, Singapore
3State Key Laboratory of Oncology in Southern China, Sun Yat-Sen University Cancer Centre, Guangzhou, China;
4Department of Clinical Oncology, Nanyang city first people’s hospital, Henan, China
5 Key laboratory for Major Obstetric Disease of Guangdong Province, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
6 Department of Clinical Oncology, The University of Hong Kong, Hong Kong

* These two authors contributed equally to this project
# Corresponding author

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