Get access

Expression of NEDD-1, a PTEN regulator, in gastric and colorectal carcinomas

Authors


  • Received 14 November 2007.

    Accepted 15 January 2008.

Sug Hyung Lee, Department of Pathology, College of Medicine, The Catholic University of Korea, 505 Banpo-dong, Socho-gu, Seoul 137-701, Korea. e-mail suhulee@catholic.ac.kr

Abstract

Recent studies have disclosed that NEDD4-1 regulates PTEN activity by ubiquitination. NEDD4-1 negatively regulates PTEN in cytosol and acts as an oncogenic protein. By contrast, NEDD4-1 promotes PTEN nuclear import and acts as a tumor suppressor. Despite the importance of NEDD4-1 in PTEN regulation in cancer cells, expression of NEDD4-1 protein in cancer tissues is unknown. The aim of this study was to analyze NEDD4-1 expression in colorectal and gastric cancer tissues. We investigated NEDD4-1 protein expression in 103 colorectal and 60 gastric carcinoma tissues by immunohistochemistry using a tissue microarray approach. In the cancers, expression of NEDD4-1 was detected in 82 (80%) of the colorectal carcinomas and 45 (75%) of the gastric carcinomas in cytoplasm. By contrast, the normal mucosal cells of both stomach and colon showed no or very weak expression of NEDD4-1. There was no significant association of NEDD4-1 expression with clinicopathologic characteristics, including invasion, metastasis and stage. Our data indicate that NEDD4-1 overexpression is a feature of both colorectal and gastric carcinomas. The increased expression of NEDD4-1 in malignant gastric and colorectal cells compared to their normal epithelial cells suggests that NEDD4-1 expression may play a role in colorectal and gastric cancer development.

Ancillary