Letters To The Editor
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World J Gastroenterol. Nov 21, 2012; 18(43): 6345-6348
Published online Nov 21, 2012. doi: 10.3748/wjg.v18.i43.6345
Is NEDD4-1 a negative regulator of phosphatase and tensin homolog in gastric carcinogenesis?
Zhen Yang, Xiao-Gang Yuan, Jiang Chen, Nong-Hua Lu
Zhen Yang, Xiao-Gang Yuan, Jiang Chen, Nong-Hua Lu, Department of Gastroenterology, the First Affiliated Hospital of Nanchang University, Nanchang 330006, Jiangxi Province, China
Author contributions: Yang Z and Lu NH designed the study; Yang Z, Yuan XG and Chen J performed the study; Yang Z analyzed the data; Yang Z and Lu NH drafted the manuscript.
Supported by Grants from the National Natural Science Foundation of China, No. 81060038; and the Graduate Innovative Fund of Jiangxi Province, No. YC10A020
Correspondence to: Nong-Hua Lu, MD, Department of Gastroenterology, the First Affiliated Hospital of Nanchang University, Nanchang 330006, Jiangxi Province, China. lunonghua@ncu.edu.cn
Telephone: +86-791-88692705 Fax: +86-791-88623153
Received: April 11, 2012
Revised: August 3, 2012
Accepted: August 14, 2012
Published online: November 21, 2012
Abstract

The expression of phosphatase and tensin homolog (PTEN), a tumor suppressor gene, is frequently down-regulated in gastric carcinomas due to mutation, loss of heterozygosity, and promoter hypermethylation. However, it is unknown if additional mechanisms may account for the down-regulation of PTEN expression. While neuronal precursor cell-expressed developmentally down-regulated 4-1 (NEDD4-1) is believed to be a potential dual regulator of PTEN, there are conflicting reports regarding their interaction. To gain further insight into the role of NEDD4-1 and its association with PTEN in gastric carcinoma development, we measured the protein expression of NEDD4-1 and PTEN in gastric mucosae with various pathological lesions and found that NEDD4-1 increased from normal gastric mucosa to intestinal metaplasia and decreased from dysplasia to gastric carcinoma. These changes did not correlate with PTEN expression changes during gastric carcinogenesis. Moreover, we found similar results in protein levels in the primary tumors and adjacent non-tumorous tissues. These results differ from a previous report showing that expression of NEDD4-1 is up-regulated in gastric carcinomas, and show a more complex pattern of NEDD4-1 gene expression during gastric carcinogenesis.

Keywords: Neuronal precursor cell-expressed developmentally down-regulated 4-1; Phosphatase and tensin homolog; Gastric carcinogenesis; Immunohistochemistry